.eslintignore

@@ -0,0 +1,25 @@
+.rvmrc
+.DS_Store
+/tmp/
+*.sublime-project
+*.sublime-workspace
+npm-debug.log
+sauce_connect.log*
+.idea
+yarn-error.log
+node_modules
+/handlebars-release.tgz
+.nyc_output
+
+# Generated files
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+
+# Third-party or files that must remain unchanged
+/spec/expected/
+/spec/vendor
+
+# JS-Snippets
+src/*.js

.eslintrc.js

@@ -1,117 +1,66 @@
 module.exports = {
-  "extends": ["eslint:recommended","plugin:compat/recommended"],
-  "globals": {
-    "self": false
+  extends: ['eslint:recommended', 'plugin:compat/recommended', 'prettier'],
+  globals: {
+    self: false
   },
-  "env": {
-    "node": true,
-    "es6": true
+  env: {
+    node: true,
+    es6: true
   },
-  "rules": {
-    // overrides eslint:recommended defaults
-    "no-sparse-arrays": "off",
-    "no-func-assign": "off",
-    "no-console": "warn",
-    "no-debugger": "warn",
-    "no-unreachable": "warn",
-
-    // Possible Errors //
-    //-----------------//
-    "no-unsafe-negation": "error",
+  rules: {
+    'no-console': 'warn',
 
+    // temporarily disabled until the violating places are fixed.
+    'no-func-assign': 'off',
+    'no-sparse-arrays': 'off',
 
     // Best Practices //
     //----------------//
-    "curly": "error",
-    "default-case": "warn",
-    "dot-notation": ["error", { "allowKeywords": false }],
-    "guard-for-in": "warn",
-    "no-alert": "error",
-    "no-caller": "error",
-    "no-div-regex": "warn",
-    "no-eval": "error",
-    "no-extend-native": "error",
-    "no-extra-bind": "error",
-    "no-floating-decimal": "error",
-    "no-implied-eval": "error",
-    "no-iterator": "error",
-    "no-labels": "error",
-    "no-lone-blocks": "error",
-    "no-loop-func": "error",
-    "no-multi-spaces": "error",
-    "no-multi-str": "warn",
-    "no-global-assign": "error",
-    "no-new": "error",
-    "no-new-func": "error",
-    "no-new-wrappers": "error",
-    "no-octal-escape": "error",
-    "no-process-env": "error",
-    "no-proto": "error",
-    "no-return-assign": "error",
-    "no-script-url": "error",
-    "no-self-compare": "error",
-    "no-sequences": "error",
-    "no-throw-literal": "error",
-    "no-unused-expressions": "error",
-    "no-warning-comments": "warn",
-    "no-with": "error",
-    "radix": "error",
-    "wrap-iife": "error",
-
+    'default-case': 'warn',
+    'guard-for-in': 'warn',
+    'no-alert': 'error',
+    'no-caller': 'error',
+    'no-div-regex': 'warn',
+    'no-eval': 'error',
+    'no-extend-native': 'error',
+    'no-extra-bind': 'error',
+    'no-floating-decimal': 'error',
+    'no-implied-eval': 'error',
+    'no-iterator': 'error',
+    'no-labels': 'error',
+    'no-lone-blocks': 'error',
+    'no-loop-func': 'error',
+    'no-multi-str': 'warn',
+    'no-global-assign': 'error',
+    'no-new': 'error',
+    'no-new-func': 'error',
+    'no-new-wrappers': 'error',
+    'no-octal-escape': 'error',
+    'no-process-env': 'error',
+    'no-proto': 'error',
+    'no-return-assign': 'error',
+    'no-script-url': 'error',
+    'no-self-compare': 'error',
+    'no-sequences': 'error',
+    'no-throw-literal': 'error',
+    'no-unused-expressions': 'error',
+    'no-warning-comments': 'warn',
+    'no-with': 'error',
+    radix: 'error',
 
     // Variables //
     //-----------//
-    "no-catch-shadow": "error",
-    "no-label-var": "error",
-    "no-shadow-restricted-names": "error",
-    "no-undef-init": "error",
-    "no-use-before-define": ["error", "nofunc"],
-
-
-    // Stylistic Issues //
-    //------------------//
-    "comma-dangle": ["error", "never"],
-    "quote-props": ["error", "as-needed", { "keywords": true, "unnecessary": false }],
-    "brace-style": ["error", "1tbs", { "allowSingleLine": true }],
-    "camelcase": "error",
-    "comma-spacing": ["error", { "before": false, "after": true }],
-    "comma-style": ["error", "last"],
-    "consistent-this": ["warn", "self"],
-    "eol-last": "error",
-    "func-style": ["error", "declaration"],
-    "key-spacing": ["error", {
-      "beforeColon": false,
-      "afterColon": true
-    }],
-    "new-cap": "error",
-    "new-parens": "error",
-    "no-array-constructor": "error",
-    "no-lonely-if": "error",
-    "no-mixed-spaces-and-tabs": "error",
-    "no-nested-ternary": "warn",
-    "no-new-object": "error",
-    "no-spaced-func": "error",
-    "no-trailing-spaces": "error",
-    "no-extra-parens": ["error", "functions"],
-    "quotes": ["error", "single", "avoid-escape"],
-    "semi": "error",
-    "semi-spacing": ["error", { "before": false, "after": true }],
-    "keyword-spacing": "error",
-    "space-before-blocks": ["error", "always"],
-    "space-before-function-paren": ["error", { "anonymous": "never", "named": "never" }],
-    "space-in-parens": ["error", "never"],
-    "space-infix-ops": "error",
-    "space-unary-ops": "error",
-    "spaced-comment": ["error", "always", { "markers": [","] }],
-    "wrap-regex": "warn",
+    'no-label-var': 'error',
+    'no-undef-init': 'error',
+    'no-use-before-define': ['error', 'nofunc'],
 
     // ECMAScript 6 //
     //--------------//
-    "no-var": "warn"
+    'no-var': 'error'
   },
-  "parserOptions": {
-    "sourceType": "module",
-    "ecmaVersion": 6,
-    "ecmaFeatures": {}
+  parserOptions: {
+    sourceType: 'module',
+    ecmaVersion: 6,
+    ecmaFeatures: {}
   }
-}
+};

.gitignore

@@ -1,15 +1,20 @@
-vendor
 .rvmrc
 .DS_Store
-lib/handlebars/compiler/parser.js
-/dist/
 /tmp/
-/coverage/
-node_modules
 *.sublime-project
 *.sublime-workspace
 npm-debug.log
 sauce_connect.log*
 .idea
-yarn-error.log
+/yarn-error.log
+/yarn.lock
+node_modules
 /handlebars-release.tgz
+.nyc_output
+
+# Generated files
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+/spec/tmp/*

.prettierignore

@@ -0,0 +1,22 @@
+.rvmrc
+.DS_Store
+/tmp/
+*.sublime-project
+*.sublime-workspace
+npm-debug.log
+sauce_connect.log*
+.idea
+yarn-error.log
+node_modules
+/handlebars-release.tgz
+.nyc_output
+
+# Generated files
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+
+# Third-party or files that must remain unchanged
+/spec/expected/
+/spec/vendor

.travis.yml

@@ -1,26 +1,39 @@
 language: node_js
-before_install:
-- npm install -g grunt-cli
-script:
-- grunt --stack travis
+jobs:
+  include:
+  - stage: test
+    name: check javascript (eslint)
+    node_js: lts/*
+    script: npm run lint
+  - stage: test
+    name: check formatting (prettier)
+    node_js: lts/*
+    script: npm run check-format
+  - stage: test
+    name: check typescript definitions (dtslint)
+    node_js: lts/*
+    script: npm run dtslint
+  - stage: test
+    name: extensive tests and publish to aws
+    script: npm run extensive-tests-and-publish-to-aws
+    env:
+    - S3_BUCKET_NAME=builds.handlebarsjs.com
+    - secure: ckyEe5dzjdFDjmZ6wIrhGm0CFBEnKq8c1dYptfgVV/Q5/nJFGzu8T0yTjouS/ERxzdT2H327/63VCxhFnLCRHrsh4rlW/rCy4XI3O/0TeMLgFPa4TXkO8359qZ4CB44TBb3NsJyQXNMYdJpPLTCVTMpuiqqkFFOr+6OeggR7ufA=
+    - secure: Nm4AgSfsgNB21kgKrF9Tl7qVZU8YYREhouQunFracTcZZh2NZ2XH5aHuSiXCj88B13Cr/jGbJKsZ4T3QS3wWYtz6lkyVOx3H3iI+TMtqhD9RM3a7A4O+4vVN8IioB2YjhEu0OKjwgX5gp+0uF+pLEi7Hpj6fupD3AbbL5uYcKg8=
+    - SAUCE_USERNAME=handlebars
+    - secure: 1VkLQhbsEug4ZMQ52tTOus/WLvW3Etqe7GbCzZfzsI8d2ygJPjFfzU8fNm4pVVwoTI21MaM5AQq7SVPu8DWN1YbDjJycMdY1zO3DsB9aZBxTal98fIB7ZIUce9r5z2EP6mETrsbYjZkeckzIBI0A4UVa+F2BO4KbRDXP1Db3u3I=
+    node_js: '10'
+  - stage: test
+    name: test with latest nodejs-lts
+    node_js: lts/*
+    script: npm run test
+  - stage: test
+    name: test with active nodejs
+    node_js: node
+    script: npm run test
+cache: npm
 email:
   on_failure: change
   on_success: never
-env:
-  global:
-  - S3_BUCKET_NAME=builds.handlebarsjs.com
-  - secure: ckyEe5dzjdFDjmZ6wIrhGm0CFBEnKq8c1dYptfgVV/Q5/nJFGzu8T0yTjouS/ERxzdT2H327/63VCxhFnLCRHrsh4rlW/rCy4XI3O/0TeMLgFPa4TXkO8359qZ4CB44TBb3NsJyQXNMYdJpPLTCVTMpuiqqkFFOr+6OeggR7ufA=
-  - secure: Nm4AgSfsgNB21kgKrF9Tl7qVZU8YYREhouQunFracTcZZh2NZ2XH5aHuSiXCj88B13Cr/jGbJKsZ4T3QS3wWYtz6lkyVOx3H3iI+TMtqhD9RM3a7A4O+4vVN8IioB2YjhEu0OKjwgX5gp+0uF+pLEi7Hpj6fupD3AbbL5uYcKg8=
-matrix:
-  include:
-  - node_js: '10'
-    env:
-    - PUBLISH=true
-    - secure: pLTzghtVll9yGKJI0AaB0uI8GypfWxLTaIB0ZL8//yN3nAEIKMhf/RRilYTsn/rKj2NUa7vt2edYILi3lttOUlCBOwTc9amiRms1W8Lwr/3IdWPeBLvLuH1zNJRm2lBAwU4LBSqaOwhGaxOQr6KHTnWudhNhgOucxpZfvfI/dFw=
-    - secure: yERYCf7AwL11D9uMtacly/THGV8BlzsMmrt+iQVvGA3GaY6QMmfYqf6P6cCH98sH5etd1Y+1e6YrPeMjqI6lyRllT7FptoyOdHulazQe86VQN4sc0EpqMlH088kB7gGjTut9Z+X9ViooT5XEh9WA5jXEI9pXhQJNoIHkWPuwGuY=
-cache:
-  directories:
-  - node_modules
-
 git:
   depth: 100

CONTRIBUTING.md

@@ -12,15 +12,16 @@ Documentation issues on the handlebarsjs.com site should be reported on [handleb
 
 ## Branches
 
-* The branch `4.x` contains the currently released version. Bugfixes should be made in this branch.
-* The branch `master` contains the next version. A release date is not yet specified. Maintainers
+- The branch `4.x` contains the currently released version. Bugfixes should be made in this branch.
+- The branch `master` contains the next version. A release date is not yet specified. Maintainers
   should merge the branch `4.x` into the master branch regularly.
 
 ## Pull Requests
 
 We also accept [pull requests][pull-request]!
 
 Generally we like to see pull requests that
+
 - Maintain the existing code style
 - Are focused on a single change (i.e. avoid large refactoring or style adjustments in untouched code if not the primary goal of the pull request)
 - Have [good commit messages](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
@@ -31,8 +32,8 @@ Generally we like to see pull requests that
 
 To build Handlebars.js you'll need a few things installed.
 
-* Node.js
-* [Grunt](http://gruntjs.com/getting-started)
+- Node.js
+- [Grunt](http://gruntjs.com/getting-started)
 
 Before building, you need to make sure that the Git submodule `spec/mustache` is included (i.e. the directory `spec/mustache` should not be empty). To include it, if using Git version 1.6.5 or newer, use `git clone --recursive` rather than `git clone`. Or, if you already cloned without `--recursive`, use `git submodule update --init`.
 
@@ -51,22 +52,43 @@ If you notice any problems, please report them to the GitHub issue tracker at
 ##Running Tests
 
 To run tests locally, first install all dependencies.
+
 ```sh
 npm install
 ```
 
 Clone the mustache specs into the spec/mustache folder.
+
 ```sh
 cd spec
 rm -r mustache
 git clone https://github.com/mustache/spec.git mustache
 ```
 
 From the root directory, run the tests.
+
 ```sh
 npm test
 ```
 
+## Linting and Formatting
+
+Handlebars uses `eslint` to enforce best-practices and `prettier` to auto-format files.
+We do linting and formatting in two phases:
+
+- Committed files are linted and formatted in a pre-commit hook. In this stage eslint-errors are forbidden,
+  while warnings are allowed.
+- The travis-ci job also lints all files and checks if they are formatted correctly. In this stage, warnings
+  are forbidden.
+
+You can use the following scripts to make sure that the travis-job does not fail:
+
+- **npm run lint** will run `eslint` and fail on warnings
+- **npm run format** will run `prettier` on all files
+- **npm run check-before-pull-request** will perform all most checks that travis does in its build-job, excluding the "integration-test".
+- **npm run integration-test** will run integration tests (using old NodeJS versions and integrations with webpack, babel and so on)
+  These tests only work on a Linux-machine with `nvm` installed (for running tests in multiple versions of NodeJS).
+
 ## Ember testing
 
 The current ember distribution should be tested as part of the handlebars release process. This requires building the `handlebars-source` gem locally and then executing the ember test script.
@@ -83,7 +105,7 @@ npm test
 
 ## Releasing the latest version
 
-*When releasing a previous version of Handlebars, please look into the CONTRIBUNG.md in the corresponding branch.*
+_When releasing a previous version of Handlebars, please look into the CONTRIBUNG.md in the corresponding branch._
 
 Handlebars utilizes the [release yeoman generator][generator-release] to perform most release tasks.
 
@@ -103,10 +125,10 @@ gem push handlebars-source-*.gem
 After the release, you should check that all places have really been updated. Especially verify that the `latest`-tags
 in those places still point to the latest version
 
-* [The npm-package](https://www.npmjs.com/package/handlebars) (check latest-tag)
-* [The bower package](https://github.com/components/handlebars.js) (check the package.json)
-* [The AWS S3 Bucket](https://s3.amazonaws.com/builds.handlebarsjs.com) (check latest-tag)
-* [RubyGems](https://rubygems.org/gems/handlebars-source)
+- [The npm-package](https://www.npmjs.com/package/handlebars) (check latest-tag)
+- [The bower package](https://github.com/components/handlebars.js) (check the package.json)
+- [The AWS S3 Bucket](https://s3.amazonaws.com/builds.handlebarsjs.com) (check latest-tag)
+- [RubyGems](https://rubygems.org/gems/handlebars-source)
 
 When everything is OK, the handlebars site needs to be updated to point to the new version numbers. The jsfiddle link should be updated to point to the most recent distribution for all instances in our documentation.
 

Gruntfile.js

@@ -1,45 +1,42 @@
 /* eslint-disable no-process-env */
 module.exports = function(grunt) {
-
   grunt.initConfig({
     pkg: grunt.file.readJSON('package.json'),
 
-    eslint: {
-      files: [
-        '*.js',
-        'bench/**/*.js',
-        'tasks/**/*.js',
-        'lib/**/!(*.min|parser).js',
-        'spec/**/!(*.amd|json2|require).js',
-        'integration-testing/multi-nodejs-test/*.js',
-        'integration-testing/webpack-test/*.js',
-        'integration-testing/webpack-test/src/*.js'
-      ]
-    },
-
-    clean: ['tmp', 'dist', 'lib/handlebars/compiler/parser.js', 'integration-testing/**/node_modules'],
+    clean: [
+      'tmp',
+      'dist',
+      'lib/handlebars/compiler/parser.js',
+      'integration-testing/**/node_modules'
+    ],
 
     copy: {
       dist: {
         options: {
           processContent: function(content) {
-            return grunt.template.process('/**!\n\n @license\n <%= pkg.name %> v<%= pkg.version %>\n\n<%= grunt.file.read("LICENSE") %>\n*/\n')
-                + content;
+            return (
+              grunt.template.process(
+                '/**!\n\n @license\n <%= pkg.name %> v<%= pkg.version %>\n\n<%= grunt.file.read("LICENSE") %>\n*/\n'
+              ) + content
+            );
           }
         },
-        files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/'}
-        ]
+        files: [{ expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/' }]
       },
       cdnjs: {
         files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/cdnjs'}
+          { expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/cdnjs' }
         ]
       },
       components: {
         files: [
-          {expand: true, cwd: 'components/', src: ['**'], dest: 'dist/components'},
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/components'}
+          {
+            expand: true,
+            cwd: 'components/',
+            src: ['**'],
+            dest: 'dist/components'
+          },
+          { expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/components' }
         ]
       }
     },
@@ -54,24 +51,28 @@ module.exports = function(grunt) {
         options: {
           modules: 'amd'
         },
-        files: [{
-          expand: true,
-          cwd: 'lib/',
-          src: '**/!(index).js',
-          dest: 'dist/amd/'
-        }]
+        files: [
+          {
+            expand: true,
+            cwd: 'lib/',
+            src: '**/!(index).js',
+            dest: 'dist/amd/'
+          }
+        ]
       },
 
       cjs: {
         options: {
           modules: 'common'
         },
-        files: [{
-          cwd: 'lib/',
-          expand: true,
-          src: '**/!(index).js',
-          dest: 'dist/cjs/'
-        }]
+        files: [
+          {
+            cwd: 'lib/',
+            expand: true,
+            src: '**/!(index).js',
+            dest: 'dist/cjs/'
+          }
+        ]
       }
     },
     webpack: {
@@ -80,7 +81,12 @@ module.exports = function(grunt) {
         module: {
           loaders: [
             // the optional 'runtime' transformer tells babel to require the runtime instead of inlining it.
-            { test: /\.jsx?$/, exclude: /node_modules/, loader: 'babel-loader?optional=runtime&loose=es6.modules&auxiliaryCommentBefore=istanbul%20ignore%20next' }
+            {
+              test: /\.jsx?$/,
+              exclude: /node_modules/,
+              loader:
+                'babel-loader?optional=runtime&loose=es6.modules&auxiliaryCommentBefore=istanbul%20ignore%20next'
+            }
           ]
         },
         output: {
@@ -129,15 +135,17 @@ module.exports = function(grunt) {
         preserveComments: /(?:^!|@(?:license|preserve|cc_on))/
       },
       dist: {
-        files: [{
-          cwd: 'dist/',
-          expand: true,
-          src: ['handlebars*.js', '!*.min.js'],
-          dest: 'dist/',
-          rename: function(dest, src) {
-            return dest + src.replace(/\.js$/, '.min.js');
+        files: [
+          {
+            cwd: 'dist/',
+            expand: true,
+            src: ['handlebars*.js', '!*.min.js'],
+            dest: 'dist/',
+            rename: function(dest, src) {
+              return dest + src.replace(/\.js$/, '.min.js');
+            }
           }
-        }]
+        ]
       }
     },
 
@@ -161,44 +169,51 @@ module.exports = function(grunt) {
       all: {
         options: {
           build: process.env.TRAVIS_JOB_ID,
-          urls: ['http://localhost:9999/spec/?headless=true', 'http://localhost:9999/spec/amd.html?headless=true'],
+          urls: [
+            'http://localhost:9999/spec/?headless=true',
+            'http://localhost:9999/spec/amd.html?headless=true'
+          ],
           detailedError: true,
           concurrency: 4,
           browsers: [
-            {browserName: 'chrome'},
-            {browserName: 'firefox', platform: 'Linux'},
+            { browserName: 'chrome' },
+            { browserName: 'firefox', platform: 'Linux' },
             // {browserName: 'safari', version: 9, platform: 'OS X 10.11'},
             // {browserName: 'safari', version: 8, platform: 'OS X 10.10'},
-            {browserName: 'internet explorer', version: 11, platform: 'Windows 8.1'},
-            {browserName: 'internet explorer', version: 10, platform: 'Windows 8'}
+            {
+              browserName: 'internet explorer',
+              version: 11,
+              platform: 'Windows 8.1'
+            },
+            {
+              browserName: 'internet explorer',
+              version: 10,
+              platform: 'Windows 8'
+            }
           ]
         }
       },
       sanity: {
         options: {
           build: process.env.TRAVIS_JOB_ID,
-          urls: ['http://localhost:9999/spec/umd.html?headless=true', 'http://localhost:9999/spec/amd-runtime.html?headless=true', 'http://localhost:9999/spec/umd-runtime.html?headless=true'],
+          urls: [
+            'http://localhost:9999/spec/umd.html?headless=true',
+            'http://localhost:9999/spec/amd-runtime.html?headless=true',
+            'http://localhost:9999/spec/umd-runtime.html?headless=true'
+          ],
           detailedError: true,
           concurrency: 2,
-          browsers: [
-            {browserName: 'chrome'}
-          ]
+          browsers: [{ browserName: 'chrome' }]
         }
       }
     },
 
     bgShell: {
-      checkTypes: {
-        cmd: 'npm run checkTypes',
-        bg: false,
-        fail: true
-      },
       integrationTests: {
         cmd: './integration-testing/run-integration-tests.sh',
         bg: false,
         fail: true
       }
-
     },
 
     watch: {
@@ -208,26 +223,11 @@ module.exports = function(grunt) {
         },
 
         files: ['src/*', 'lib/**/*.js', 'spec/**/*.js'],
-        tasks: ['build', 'amd', 'tests', 'test']
+        tasks: ['on-file-change']
       }
     }
   });
 
-  // Build a new version of the library
-  this.registerTask('build', 'Builds a distributable version of the current project', [
-                    'eslint',
-                    'bgShell:checkTypes',
-                    'parser',
-                    'node',
-                    'globals']);
-
-  this.registerTask('amd', ['babel:amd', 'requirejs']);
-  this.registerTask('node', ['babel:cjs']);
-  this.registerTask('globals', ['webpack']);
-  this.registerTask('tests', ['concat:tests']);
-
-  this.registerTask('release', 'Build final packages', ['eslint', 'amd', 'uglify', 'test:min', 'copy:dist', 'copy:components', 'copy:cdnjs']);
-
   // Load tasks from npm
   grunt.loadNpmTasks('grunt-contrib-clean');
   grunt.loadNpmTasks('grunt-contrib-concat');
@@ -238,18 +238,61 @@ module.exports = function(grunt) {
   grunt.loadNpmTasks('grunt-contrib-watch');
   grunt.loadNpmTasks('grunt-babel');
   grunt.loadNpmTasks('grunt-bg-shell');
-  grunt.loadNpmTasks('grunt-eslint');
   grunt.loadNpmTasks('@knappi/grunt-saucelabs');
   grunt.loadNpmTasks('grunt-webpack');
 
   grunt.task.loadTasks('tasks');
 
+  this.registerTask(
+    'build',
+    'Builds a distributable version of the current project',
+    ['parser', 'node', 'globals']
+  );
+
+  this.registerTask('node', ['babel:cjs']);
+  this.registerTask('globals', ['webpack']);
+
+  this.registerTask('release', 'Build final packages', [
+    'amd',
+    'uglify',
+    'test:min',
+    'copy:dist',
+    'copy:components',
+    'copy:cdnjs'
+  ]);
+
+  this.registerTask('amd', ['babel:amd', 'requirejs']);
+
+  this.registerTask('test', ['test:bin', 'test:cov']);
+
   grunt.registerTask('bench', ['metrics']);
-  grunt.registerTask('sauce', process.env.SAUCE_USERNAME ? ['tests', 'connect', 'saucelabs-mocha'] : []);
 
-  grunt.registerTask('travis', process.env.PUBLISH ? ['default', 'bgShell:integrationTests', 'sauce', 'metrics', 'publish:latest'] : ['default']);
+  if (process.env.SAUCE_ACCESS_KEY) {
+    grunt.registerTask('sauce', ['concat:tests', 'connect', 'saucelabs-mocha']);
+  } else {
+    grunt.registerTask('sauce', []);
+  }
+
+  // Requires secret properties (saucelabs-credentials etc.) from .travis.yaml
+  grunt.registerTask('extensive-tests-and-publish-to-aws', [
+    'default',
+    'bgShell:integrationTests',
+    'sauce',
+    'metrics',
+    'publish-to-aws'
+  ]);
+  grunt.registerTask('on-file-change', [
+    'build',
+    'amd',
+    'concat:tests',
+    'test'
+  ]);
 
+  // === Primary tasks ===
   grunt.registerTask('dev', ['clean', 'connect', 'watch']);
   grunt.registerTask('default', ['clean', 'build', 'test', 'release']);
-  grunt.registerTask('integration-tests', ['default', 'bgShell:integrationTests']);
+  grunt.registerTask('integration-tests', [
+    'default',
+    'bgShell:integrationTests'
+  ]);
 };

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2011-2017 by Yehuda Katz
+Copyright (C) 2011-2019 by Yehuda Katz
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.markdown

@@ -11,12 +11,12 @@ Handlebars.js and Mustache are both logicless templating languages that
 keep the view and the code separated like we all know they should be.
 
 Checkout the official Handlebars docs site at
-[http://www.handlebarsjs.com](http://www.handlebarsjs.com) and the live demo at [http://tryhandlebarsjs.com/](http://tryhandlebarsjs.com/).
+[https://handlebarsjs.com/](https://handlebarsjs.com) and the live demo at [http://tryhandlebarsjs.com/](http://tryhandlebarsjs.com/).
 
 Installing
 ----------
 
-See our [installation documentation](http://handlebarsjs.com/installation.html).
+See our [installation documentation](https://handlebarsjs.com/installation/).
 
 Usage
 -----
@@ -46,23 +46,23 @@ var result = template(data);
 // </ul>
 ```
 
-Full documentation and more examples are at [handlebarsjs.com](http://handlebarsjs.com/).
+Full documentation and more examples are at [handlebarsjs.com](https://handlebarsjs.com/).
 
 Precompiling Templates
 ----------------------
 
-Handlebars allows templates to be precompiled and included as javascript code rather than the handlebars template allowing for faster startup time. Full details are located [here](http://handlebarsjs.com/precompilation.html).
+Handlebars allows templates to be precompiled and included as javascript code rather than the handlebars template allowing for faster startup time. Full details are located [here](https://handlebarsjs.com/installation/precompilation.html).
 
 Differences Between Handlebars.js and Mustache
 ----------------------------------------------
 Handlebars.js adds a couple of additional features to make writing
 templates easier and also changes a tiny detail of how partials work.
 
-- [Nested Paths](http://handlebarsjs.com/#paths)
-- [Helpers](http://handlebarsjs.com/#helpers)
-- [Block Expressions](http://handlebarsjs.com/#block-expressions)
-- [Literal Values](http://handlebarsjs.com/#literals)
-- [Delimited Comments](http://handlebarsjs.com/#comments)
+- [Nested Paths](https://handlebarsjs.com/guide/expressions.html#path-expressions)
+- [Helpers](https://handlebarsjs.com/guide/expressions.html#helpers)
+- [Block Expressions](https://handlebarsjs.com/guide/block-helpers.html#basic-blocks)
+- [Literal Values](https://handlebarsjs.com/guide/expressions.html#literal-segments)
+- [Delimited Comments](https://handlebarsjs.com/guide/#template-comments)
 
 Block expressions have the same syntax as mustache sections but should not be confused with one another. Sections are akin to an implicit `each` or `with` statement depending on the input data and helpers are explicit pieces of code that are free to implement whatever behavior they like. The [mustache spec](http://mustache.github.io/mustache.5.html) defines the exact behavior of sections. In the case of name conflicts, helpers are given priority.
 

appveyor.yml

@@ -13,8 +13,7 @@ install:
   # Clone submodules (mustache spec)
   - cmd: git submodule update --init --recursive
   # Install modules
-  - cmd: npm install
-  - cmd: npm install -g grunt-cli
+  - cmd: npm ci
 
 
 # Post-install test scripts
@@ -23,7 +22,7 @@ test_script:
   - cmd: node --version
   - cmd: npm --version
   # Run tests
-  - cmd: grunt --stack travis
+  - cmd: npm run test
 
 # Don't actually build
 build: off
@@ -34,4 +33,4 @@ on_failure:
 
 
 # Set build version format here instead of in the admin panel
-version: "{build}"
+version: "{build}"

bench/.eslintrc

@@ -1,4 +1,5 @@
 {
+  "extends": "prettier",
   "globals": {
     "require": true
   },
@@ -11,4 +12,4 @@
     "handle-callback-err": 0,
     "no-console": 0
   }
-}
+}

bench/dist-size.js

@@ -1,12 +1,14 @@
 var async = require('neo-async'),
-    fs = require('fs'),
-    zlib = require('zlib');
+  fs = require('fs'),
+  zlib = require('zlib');
 
 module.exports = function(grunt, callback) {
   var distFiles = fs.readdirSync('dist'),
-      distSizes = {};
+    distSizes = {};
 
-  async.each(distFiles, function(file, callback) {
+  async.each(
+    distFiles,
+    function(file, callback) {
       var content;
       try {
         content = fs.readFileSync('dist/' + file);
@@ -32,7 +34,10 @@ module.exports = function(grunt, callback) {
       });
     },
     function() {
-      grunt.log.writeln('Distribution sizes: ' + JSON.stringify(distSizes, undefined, 2));
+      grunt.log.writeln(
+        'Distribution sizes: ' + JSON.stringify(distSizes, undefined, 2)
+      );
       callback([distSizes]);
-    });
+    }
+  );
 };

bench/index.js

@@ -2,7 +2,7 @@ var fs = require('fs');
 
 var metrics = fs.readdirSync(__dirname);
 metrics.forEach(function(metric) {
-  if (metric === 'index.js' || !(/(.*)\.js$/.test(metric))) {
+  if (metric === 'index.js' || !/(.*)\.js$/.test(metric)) {
     return;
   }
 

bench/precompile-size.js

@@ -1,5 +1,5 @@
 var _ = require('underscore'),
-    templates = require('./templates');
+  templates = require('./templates');
 
 module.exports = function(grunt, callback) {
   // Deferring to here in case we have a build for parser, etc as part of this grunt exec
@@ -8,12 +8,17 @@ module.exports = function(grunt, callback) {
   var templateSizes = {};
   _.each(templates, function(info, template) {
     var src = info.handlebars,
-        compiled = Handlebars.precompile(src, {}),
-        knownHelpers = Handlebars.precompile(src, {knownHelpersOnly: true, knownHelpers: info.helpers});
+      compiled = Handlebars.precompile(src, {}),
+      knownHelpers = Handlebars.precompile(src, {
+        knownHelpersOnly: true,
+        knownHelpers: info.helpers
+      });
 
     templateSizes[template] = compiled.length;
     templateSizes['knownOnly_' + template] = knownHelpers.length;
   });
-  grunt.log.writeln('Precompiled sizes: ' + JSON.stringify(templateSizes, undefined, 2));
+  grunt.log.writeln(
+    'Precompiled sizes: ' + JSON.stringify(templateSizes, undefined, 2)
+  );
   callback([templateSizes]);
 };

bench/templates/arguments.js

@@ -8,5 +8,6 @@ module.exports = {
     bar: true
   },
 
-  handlebars: '{{foo person "person" 1 true foo=bar foo="person" foo=1 foo=true}}'
+  handlebars:
+    '{{foo person "person" 1 true foo=bar foo="person" foo=1 foo=true}}'
 };

bench/templates/array-each.js

@@ -1,5 +1,12 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#each names}}{{name}}{{/each}}',
   dust: '{#names}{name}{/names}',
   mustache: '{{#names}}{{name}}{{/names}}',

bench/templates/array-mustache.js

@@ -1,4 +1,11 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#names}}{{name}}{{/names}}'
 };

bench/templates/complex.js

@@ -7,9 +7,9 @@ module.exports = {
     },
     hasItems: true, // To make things fairer in mustache land due to no `{{if}}` construct on arrays
     items: [
-      {name: 'red', current: true, url: '#Red'},
-      {name: 'green', current: false, url: '#Green'},
-      {name: 'blue', current: false, url: '#Blue'}
+      { name: 'red', current: true, url: '#Red' },
+      { name: 'green', current: false, url: '#Green' },
+      { name: 'blue', current: false, url: '#Blue' }
     ]
   },
 

bench/templates/data.js

@@ -1,4 +1,11 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#each names}}{{@index}}{{name}}{{/each}}'
 };

bench/templates/depth-1.js

@@ -1,5 +1,13 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}], foo: 'bar' },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ],
+    foo: 'bar'
+  },
   handlebars: '{{#each names}}{{../foo}}{{/each}}',
   mustache: '{{#names}}{{foo}}{{/names}}',
   eco: '<% for item in @names: %><%= @foo %><% end %>'

bench/templates/depth-2.js

@@ -1,6 +1,16 @@
 module.exports = {
-  context: { names: [{bat: 'foo', name: ['Moe']}, {bat: 'foo', name: ['Larry']}, {bat: 'foo', name: ['Curly']}, {bat: 'foo', name: ['Shemp']}], foo: 'bar' },
-  handlebars: '{{#each names}}{{#each name}}{{../bat}}{{../../foo}}{{/each}}{{/each}}',
+  context: {
+    names: [
+      { bat: 'foo', name: ['Moe'] },
+      { bat: 'foo', name: ['Larry'] },
+      { bat: 'foo', name: ['Curly'] },
+      { bat: 'foo', name: ['Shemp'] }
+    ],
+    foo: 'bar'
+  },
+  handlebars:
+    '{{#each names}}{{#each name}}{{../bat}}{{../../foo}}{{/each}}{{/each}}',
   mustache: '{{#names}}{{#name}}{{bat}}{{foo}}{{/name}}{{/names}}',
-  eco: '<% for item in @names: %><% for child in item.name: %><%= item.bat %><%= @foo %><% end %><% end %>'
+  eco:
+    '<% for item in @names: %><% for child in item.name: %><%= item.bat %><%= @foo %><% end %><% end %>'
 };

bench/templates/index.js

@@ -2,7 +2,7 @@ var fs = require('fs');
 
 var templates = fs.readdirSync(__dirname);
 templates.forEach(function(template) {
-  if (template === 'index.js' || !(/(.*)\.js$/.test(template))) {
+  if (template === 'index.js' || !/(.*)\.js$/.test(template)) {
     return;
   }
   module.exports[RegExp.$1] = require('./' + RegExp.$1);

bench/templates/partial-recursion.js

@@ -1,5 +1,8 @@
 module.exports = {
-  context: { name: '1', kids: [{ name: '1.1', kids: [{name: '1.1.1', kids: []}] }] },
+  context: {
+    name: '1',
+    kids: [{ name: '1.1', kids: [{ name: '1.1.1', kids: [] }] }]
+  },
   partials: {
     mustache: { recursion: '{{name}}{{#kids}}{{>recursion}}{{/kids}}' },
     handlebars: { recursion: '{{name}}{{#each kids}}{{>recursion}}{{/each}}' }

bench/templates/partial.js

@@ -1,8 +1,16 @@
 module.exports = {
-  context: { peeps: [{name: 'Moe', count: 15}, {name: 'Larry', count: 5}, {name: 'Curly', count: 1}] },
+  context: {
+    peeps: [
+      { name: 'Moe', count: 15 },
+      { name: 'Larry', count: 5 },
+      { name: 'Curly', count: 1 }
+    ]
+  },
   partials: {
     mustache: { variables: 'Hello {{name}}! You have {{count}} new messages.' },
-    handlebars: { variables: 'Hello {{name}}! You have {{count}} new messages.' }
+    handlebars: {
+      variables: 'Hello {{name}}! You have {{count}} new messages.'
+    }
   },
 
   handlebars: '{{#each peeps}}{{>variables}}{{/each}}',

bench/templates/paths.js

@@ -1,7 +1,9 @@
 module.exports = {
-  context: { person: { name: {bar: {baz: 'Larry'}}, age: 45 } },
-  handlebars: '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}',
+  context: { person: { name: { bar: { baz: 'Larry' } }, age: 45 } },
+  handlebars:
+    '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}',
   dust: '{person.name.bar.baz}{person.age}{person.foo}{animal.age}',
-  eco: '<%= @person.name.bar.baz %><%= @person.age %><%= @person.foo %><% if @animal: %><%= @animal.age %><% end %>',
+  eco:
+    '<%= @person.name.bar.baz %><%= @person.age %><%= @person.foo %><% if @animal: %><%= @animal.age %><% end %>',
   mustache: '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}'
 };

bench/templates/variables.js

@@ -1,8 +1,7 @@
 module.exports = {
-  context: {name: 'Mick', count: 30},
+  context: { name: 'Mick', count: 30 },
   handlebars: 'Hello {{name}}! You have {{count}} new messages.',
   dust: 'Hello {name}! You have {count} new messages.',
   mustache: 'Hello {{name}}! You have {{count}} new messages.',
   eco: 'Hello <%= @name %>! You have <%= @count %> new messages.'
 };
-

bench/throughput.js

@@ -1,19 +1,27 @@
 var _ = require('underscore'),
-    runner = require('./util/template-runner'),
-
-    eco, dust, Handlebars, Mustache;
+  runner = require('./util/template-runner'),
+  eco,
+  dust,
+  Handlebars,
+  Mustache;
 
 try {
   dust = require('dustjs-linkedin');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 try {
   Mustache = require('mustache');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 try {
   eco = require('eco');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 function error() {
   throw new Error('EWOT');
@@ -22,21 +30,28 @@ function error() {
 function makeSuite(bench, name, template, handlebarsOnly) {
   // Create aliases to minimize any impact from having to walk up the closure tree.
   var templateName = name,
-
-      context = template.context,
-      partials = template.partials,
-
-      handlebarsOut,
-      compatOut,
-      dustOut,
-      ecoOut,
-      mustacheOut;
-
-  var handlebar = Handlebars.compile(template.handlebars, {data: false}),
-      compat = Handlebars.compile(template.handlebars, {data: false, compat: true}),
-      options = {helpers: template.helpers};
-  _.each(template.partials && template.partials.handlebars, function(partial, partialName) {
-    Handlebars.registerPartial(partialName, Handlebars.compile(partial, {data: false}));
+    context = template.context,
+    partials = template.partials,
+    handlebarsOut,
+    compatOut,
+    dustOut,
+    ecoOut,
+    mustacheOut;
+
+  var handlebar = Handlebars.compile(template.handlebars, { data: false }),
+    compat = Handlebars.compile(template.handlebars, {
+      data: false,
+      compat: true
+    }),
+    options = { helpers: template.helpers };
+  _.each(template.partials && template.partials.handlebars, function(
+    partial,
+    partialName
+  ) {
+    Handlebars.registerPartial(
+      partialName,
+      Handlebars.compile(partial, { data: false })
+    );
   });
 
   handlebarsOut = handlebar(context, options);
@@ -58,7 +73,9 @@ function makeSuite(bench, name, template, handlebarsOnly) {
       dustOut = false;
       dust.loadSource(dust.compile(template.dust, templateName));
 
-      dust.render(templateName, context, function(err, out) { dustOut = out; });
+      dust.render(templateName, context, function(err, out) {
+        dustOut = out;
+      });
 
       bench('dust', function() {
         dust.render(templateName, context, function() {});
@@ -84,7 +101,7 @@ function makeSuite(bench, name, template, handlebarsOnly) {
 
   if (Mustache) {
     var mustacheSource = template.mustache,
-        mustachePartials = partials && partials.mustache;
+      mustachePartials = partials && partials.mustache;
 
     if (mustacheSource) {
       mustacheOut = Mustache.to_html(mustacheSource, context, mustachePartials);
@@ -107,9 +124,16 @@ function makeSuite(bench, name, template, handlebarsOnly) {
     b = b.replace(/\s/g, '');
 
     if (handlebarsOut !== b) {
-      throw new Error('Template output mismatch: ' + name
-            + '\n\nHandlebars: ' + handlebarsOut
-            + '\n\n' + lang + ': ' + b);
+      throw new Error(
+        'Template output mismatch: ' +
+          name +
+          '\n\nHandlebars: ' +
+          handlebarsOut +
+          '\n\n' +
+          lang +
+          ': ' +
+          b
+      );
     }
   }
 

bench/util/benchwarmer.js

@@ -1,5 +1,5 @@
 var _ = require('underscore'),
-    Benchmark = require('benchmark');
+  Benchmark = require('benchmark');
 
 function BenchWarmer() {
   this.benchmarks = [];
@@ -29,20 +29,25 @@ BenchWarmer.prototype = {
     });
   },
   push: function(name, fn) {
-    if (this.names.indexOf(name) == -1) {
+    if (this.names.indexOf(name) === -1) {
       this.names.push(name);
     }
 
-    var first = this.first, suiteName = this.suiteName, self = this;
+    var first = this.first,
+      suiteName = this.suiteName,
+      self = this;
     this.first = false;
 
     var bench = new Benchmark(fn, {
       name: this.suiteName + ': ' + name,
       onComplete: function() {
-        if (first) { self.startLine(suiteName); }
+        if (first) {
+          self.startLine(suiteName);
+        }
         self.writeBench(bench);
         self.currentBenches.push(bench);
-      }, onError: function() {
+      },
+      onError: function() {
         self.errors[this.name] = this;
       }
     });
@@ -75,20 +80,23 @@ BenchWarmer.prototype = {
         });
         print('\n');
 
-        var errors = false, prop, bench;
+        var errors = false,
+          prop,
+          bench;
         for (prop in self.errors) {
-          if (self.errors.hasOwnProperty(prop)
-              && self.errors[prop].error.message !== 'EWOT') {
+          if (
+            Object.prototype.hasOwnProperty.call(self, prop) &&
+            self.errors[prop].error.message !== 'EWOT'
+          ) {
             errors = true;
             break;
           }
         }
 
         if (errors) {
           print('\n\nErrors:\n');
-          for (prop in self.errors) {
-            if (self.errors.hasOwnProperty(prop)
-                && self.errors[prop].error.message !== 'EWOT') {
+          Object.keys(self.errors).forEach(function(prop) {
+            if (self.errors[prop].error.message !== 'EWOT') {
               bench = self.errors[prop];
               print('\n' + bench.name + ':\n');
               print(bench.error.message);
@@ -97,7 +105,7 @@ BenchWarmer.prototype = {
               }
               print('\n');
             }
-          }
+          });
         }
 
         callback();
@@ -108,23 +116,39 @@ BenchWarmer.prototype = {
   },
 
   scaleTimes: function() {
-    var scaled = this.scaled = {};
-    _.each(this.times, function(times, name) {
-      var output = scaled[name] = {};
-
-      _.each(times, function(time, lang) {
-        output[lang] = ((time - this.minimum) / (this.maximum - this.minimum) * 100).toFixed(2);
-      }, this);
-    }, this);
+    var scaled = (this.scaled = {});
+    _.each(
+      this.times,
+      function(times, name) {
+        var output = (scaled[name] = {});
+
+        _.each(
+          times,
+          function(time, lang) {
+            output[lang] = (
+              ((time - this.minimum) / (this.maximum - this.minimum)) *
+              100
+            ).toFixed(2);
+          },
+          this
+        );
+      },
+      this
+    );
   },
 
   printHeader: function(title, winners) {
-    var benchSize = 0, names = this.names, i, l;
+    var benchSize = 0,
+      names = this.names,
+      i,
+      l;
 
     for (i = 0, l = names.length; i < l; i++) {
       var name = names[i];
 
-      if (benchSize < name.length) { benchSize = name.length; }
+      if (benchSize < name.length) {
+        benchSize = name.length;
+      }
     }
 
     this.nameSize = benchSize + 2;
@@ -147,7 +171,9 @@ BenchWarmer.prototype = {
   },
 
   startLine: function(name) {
-    var winners = Benchmark.map(this.winners(this.currentBenches), function(bench) {
+    var winners = Benchmark.map(this.winners(this.currentBenches), function(
+      bench
+    ) {
       return bench.name.split(': ')[1];
     });
 
@@ -165,9 +191,9 @@ BenchWarmer.prototype = {
 
     if (!bench.error) {
       var count = bench.hz,
-          moe = count * bench.stats.rme / 100,
-          minimum,
-          maximum;
+        moe = (count * bench.stats.rme) / 100,
+        minimum,
+        maximum;
 
       count = Math.round(count / 1000);
       moe = Math.round(moe / 1000);

bench/util/template-runner.js

@@ -1,12 +1,12 @@
 var _ = require('underscore'),
-    BenchWarmer = require('./benchwarmer'),
-    templates = require('../templates');
+  BenchWarmer = require('./benchwarmer'),
+  templates = require('../templates');
 
 module.exports = function(grunt, makeSuite, callback) {
   var warmer = new BenchWarmer();
 
   var handlebarsOnly = grunt.option('handlebars-only'),
-      grep = grunt.option('grep');
+    grep = grunt.option('grep');
   if (grep) {
     grep = new RegExp(grep);
   }

bin/handlebars

@@ -1,127 +1,123 @@
 #!/usr/bin/env node
 
-var optimist = require('optimist')
-    .usage('Precompile handlebar templates.\nUsage: $0 [template|directory]...', {
-      'f': {
-        'type': 'string',
-        'description': 'Output File',
-        'alias': 'output'
-      },
-      'map': {
-        'type': 'string',
-        'description': 'Source Map File'
-      },
-      'a': {
-        'type': 'boolean',
-        'description': 'Exports amd style (require.js)',
-        'alias': 'amd'
-      },
-      'c': {
-        'type': 'string',
-        'description': 'Exports CommonJS style, path to Handlebars module',
-        'alias': 'commonjs',
-        'default': null
-      },
-      'h': {
-        'type': 'string',
-        'description': 'Path to handlebar.js (only valid for amd-style)',
-        'alias': 'handlebarPath',
-        'default': ''
-      },
-      'k': {
-        'type': 'string',
-        'description': 'Known helpers',
-        'alias': 'known'
-      },
-      'o': {
-        'type': 'boolean',
-        'description': 'Known helpers only',
-        'alias': 'knownOnly'
-      },
-      'm': {
-        'type': 'boolean',
-        'description': 'Minimize output',
-        'alias': 'min'
-      },
-      'n': {
-        'type': 'string',
-        'description': 'Template namespace',
-        'alias': 'namespace',
-        'default': 'Handlebars.templates'
-      },
-      's': {
-        'type': 'boolean',
-        'description': 'Output template function only.',
-        'alias': 'simple'
-      },
-      'N': {
-        'type': 'string',
-        'description': 'Name of passed string templates. Optional if running in a simple mode. Required when operating on multiple templates.',
-        'alias': 'name'
-      },
-      'i': {
-        'type': 'string',
-        'description': 'Generates a template from the passed CLI argument.\n"-" is treated as a special value and causes stdin to be read for the template value.',
-        'alias': 'string'
-      },
-      'r': {
-        'type': 'string',
-        'description': 'Template root. Base value that will be stripped from template names.',
-        'alias': 'root'
-      },
-      'p': {
-        'type': 'boolean',
-        'description': 'Compiling a partial template',
-        'alias': 'partial'
-      },
-      'd': {
-        'type': 'boolean',
-        'description': 'Include data when compiling',
-        'alias': 'data'
-      },
-      'e': {
-        'type': 'string',
-        'description': 'Template extension.',
-        'alias': 'extension',
-        'default': 'handlebars'
-      },
-      'b': {
-        'type': 'boolean',
-        'description': 'Removes the BOM (Byte Order Mark) from the beginning of the templates.',
-        'alias': 'bom'
-      },
-      'v': {
-        'type': 'boolean',
-        'description': 'Prints the current compiler version',
-        'alias': 'version'
-      },
+const yargs = require('yargs')
+  .usage('Precompile handlebar templates.\nUsage: $0 [template|directory]...')
+  .option('f', {
+    type: 'string',
+    description: 'Output File',
+    alias: 'output'
+  })
+  .option('map', {
+    type: 'string',
+    description: 'Source Map File'
+  })
+  .option('a', {
+    type: 'boolean',
+    description: 'Exports amd style (require.js)',
+    alias: 'amd'
+  })
+  .option('c', {
+    type: 'string',
+    description: 'Exports CommonJS style, path to Handlebars module',
+    alias: 'commonjs',
+    default: null
+  })
+  .option('h', {
+    type: 'string',
+    description: 'Path to handlebar.js (only valid for amd-style)',
+    alias: 'handlebarPath',
+    default: ''
+  })
+  .option('k', {
+    type: 'string',
+    description: 'Known helpers',
+    alias: 'known'
+  })
+  .option('o', {
+    type: 'boolean',
+    description: 'Known helpers only',
+    alias: 'knownOnly'
+  })
+  .option('m', {
+    type: 'boolean',
+    description: 'Minimize output',
+    alias: 'min'
+  })
+  .option('n', {
+    type: 'string',
+    description: 'Template namespace',
+    alias: 'namespace',
+    default: 'Handlebars.templates'
+  })
+  .option('s', {
+    type: 'boolean',
+    description: 'Output template function only.',
+    alias: 'simple'
+  })
+  .option('N', {
+    type: 'string',
+    description:
+      'Name of passed string templates. Optional if running in a simple mode. Required when operating on multiple templates.',
+    alias: 'name'
+  })
+  .option('i', {
+    type: 'string',
+    description:
+      'Generates a template from the passed CLI argument.\n"-" is treated as a special value and causes stdin to be read for the template value.',
+    alias: 'string'
+  })
+  .option('r', {
+    type: 'string',
+    description:
+      'Template root. Base value that will be stripped from template names.',
+    alias: 'root'
+  })
+  .option('p', {
+    type: 'boolean',
+    description: 'Compiling a partial template',
+    alias: 'partial'
+  })
+  .option('d', {
+    type: 'boolean',
+    description: 'Include data when compiling',
+    alias: 'data'
+  })
+  .option('e', {
+    type: 'string',
+    description: 'Template extension.',
+    alias: 'extension',
+    default: 'handlebars'
+  })
+  .option('b', {
+    type: 'boolean',
+    description:
+      'Removes the BOM (Byte Order Mark) from the beginning of the templates.',
+    alias: 'bom'
+  })
+  .option('v', {
+    type: 'boolean',
+    description: 'Prints the current compiler version',
+    alias: 'version'
+  })
+  .option('help', {
+    type: 'boolean',
+    description: 'Outputs this message'
+  })
+  .wrap(120);
 
-      'help': {
-        'type': 'boolean',
-        'description': 'Outputs this message'
-      }
-    })
-
-    .wrap(120)
-    .check(function(argv) {
-      if (argv.version) {
-        return;
-      }
-    });
-
-
-var argv = optimist.argv;
+const argv = yargs.argv;
 argv.files = argv._;
 delete argv._;
 
-var Precompiler = require('../dist/cjs/precompiler');
+const Precompiler = require('../dist/cjs/precompiler');
 Precompiler.loadTemplates(argv, function(err, opts) {
+
   if (err) {
     throw err;
   }
 
   if (opts.help || (!opts.templates.length && !opts.version)) {
-    optimist.showHelp();
+    yargs.showHelp();
   } else {
     Precompiler.cli(opts);
   }

components/bower.json

@@ -1,6 +1,6 @@
 {
   "name": "handlebars",
-  "version": "4.5.1",
+  "version": "4.7.4",
   "main": "handlebars.js",
   "license": "MIT",
   "dependencies": {}

components/handlebars.js.nuspec

@@ -2,7 +2,7 @@
 <package>
 	<metadata>
 		<id>handlebars.js</id>
-		<version>4.5.1</version>
+		<version>4.7.4</version>
 		<authors>handlebars.js Authors</authors>
 		<licenseUrl>https://github.com/wycats/handlebars.js/blob/master/LICENSE</licenseUrl>
 		<projectUrl>https://github.com/wycats/handlebars.js/</projectUrl>

components/package.json

@@ -1,6 +1,6 @@
 {
   "name": "handlebars",
-  "version": "4.5.1",
+  "version": "4.7.4",
   "license": "MIT",
   "jspm": {
     "main": "handlebars",

integration-testing/multi-nodejs-test/.eslintrc.js

@@ -1,12 +1,13 @@
 module.exports = {
-  "extends": "eslint:recommended",
-  "globals": {
-    "self": false
+  extends: ['eslint:recommended', 'plugin:es5/no-es2015', 'prettier'],
+  globals: {
+    self: false
   },
-  "env": {
-    "node": true
+  env: {
+    node: true
   },
-  "rules": {
-    'no-console': 'off'
+  rules: {
+    'no-console': 'off',
+    'no-var': 'off'
   }
-}
+};

integration-testing/multi-nodejs-test/run-handlebars.js

@@ -5,7 +5,7 @@ var Handlebars = require('handlebars');
 console.log('Testing built Handlebars with Node version ' + process.version);
 
 var template = Handlebars.compile('Author: {{author}}');
-var output = template({author: 'Yehuda'});
+var output = template({ author: 'Yehuda' });
 assert.strictEqual(output, 'Author: Yehuda');
 
 console.log('Success');

integration-testing/multi-nodejs-test/test.sh

@@ -12,7 +12,8 @@ cd "$( dirname "$( readlink -f "$0" )" )" || exit 1
 # It does (almost) not test for correctness, because that is already done in the mocha-tests.
 # And it does not use any NodeJS based testing framwork to make this part independent of the Node version.
 
-# A list of NodeJS versions is expected as cli-args
+unset npm_config_prefix
+
 echo "Handlebars should be able to run in various versions of NodeJS"
 for i in  0.10 0.12 4 5 6 7 8 9 10 11 ; do
     rm target node_modules package-lock.json -rf
@@ -23,4 +24,4 @@ for i in  0.10 0.12 4 5 6 7 8 9 10 11 ; do
     nvm exec "$i" npm run test-precompile || exit 1
 
     echo Success
-done
+done

integration-testing/webpack-babel-test/src/handlebars-inline-precompile-test.js

@@ -1,12 +1,12 @@
-import * as Handlebars from 'handlebars/runtime'
+import * as Handlebars from 'handlebars/runtime';
 import hbs from 'handlebars-inline-precompile';
-import {assertEquals} from "../../webpack-test/src/lib/assert";
+import { assertEquals } from '../../webpack-test/src/lib/assert';
 
 Handlebars.registerHelper('loud', function(text) {
-    return text.toUpperCase();
+  return text.toUpperCase();
 });
 
 const template = hbs`{{loud name}}`;
-const output = template({name: 'yehuda'})
+const output = template({ name: 'yehuda' });
 
-assertEquals(output, 'YEHUDA')
+assertEquals(output, 'YEHUDA');

integration-testing/webpack-babel-test/src/lib/assert.js

@@ -1,5 +1,5 @@
 export function assertEquals(actual, expected) {
-    if (actual !== expected) {
-        throw new Error(`Expected "${actual}" to equal "${expected}"`);
-    }
+  if (actual !== expected) {
+    throw new Error(`Expected "${actual}" to equal "${expected}"`);
+  }
 }

integration-testing/webpack-babel-test/webpack.config.js

@@ -3,30 +3,30 @@ const fs = require('fs');
 const testFiles = fs.readdirSync('src');
 const entryPoints = {};
 testFiles
-    .filter(file => file.match(/-test.js$/))
-    .forEach(file => {
-        entryPoints[file] = `./src/${file}`;
-    });
+  .filter(file => file.match(/-test.js$/))
+  .forEach(file => {
+    entryPoints[file] = `./src/${file}`;
+  });
 
 module.exports = {
-    entry: entryPoints,
-    output: {
-        filename: '[name]',
-        path: __dirname + '/dist'
-    },
-    module: {
-        rules: [
-            {
-                test: /\.js?$/,
-                exclude: /node_modules/,
-                use: {
-                    loader: 'babel-loader',
-                    options: { cacheDirectory: false },
-                }
-            }
-        ]
-    },
-    optimization: {
-        minimize: false
-    }
+  entry: entryPoints,
+  output: {
+    filename: '[name]',
+    path: __dirname + '/dist'
+  },
+  module: {
+    rules: [
+      {
+        test: /\.js?$/,
+        exclude: /node_modules/,
+        use: {
+          loader: 'babel-loader',
+          options: { cacheDirectory: false }
+        }
+      }
+    ]
+  },
+  optimization: {
+    minimize: false
+  }
 };

integration-testing/webpack-test/src/handlebars-default-import-pre-4.2-test.js

@@ -1,6 +1,6 @@
 import Handlebars from 'handlebars/dist/handlebars';
 
-import {assertEquals} from './lib/assert';
+import { assertEquals } from './lib/assert';
 
 const template = Handlebars.compile('Author: {{author}}');
-assertEquals(template({author: 'Yehuda'}), 'Author: Yehuda');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-default-import-test.js

@@ -1,6 +1,5 @@
 import Handlebars from 'handlebars';
-import {assertEquals} from './lib/assert';
-
+import { assertEquals } from './lib/assert';
 
 const template = Handlebars.compile('Author: {{author}}');
-assertEquals(template({author: 'Yehuda'}), 'Author: Yehuda');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-loader-test.js

@@ -1,8 +1,10 @@
-import {assertEquals} from './lib/assert';
+import { assertEquals } from './lib/assert';
 
 import testTemplate from './test-template.handlebars';
-assertEquals(testTemplate({author: 'Yehuda'}).trim(), 'Author: Yehuda');
-
+assertEquals(testTemplate({ author: 'Yehuda' }).trim(), 'Author: Yehuda');
 
 const testTemplateRequire = require('./test-template.handlebars');
-assertEquals(testTemplateRequire({author: 'Yehuda'}).trim(), 'Author: Yehuda');
+assertEquals(
+  testTemplateRequire({ author: 'Yehuda' }).trim(),
+  'Author: Yehuda'
+);

integration-testing/webpack-test/src/handlebars-require-vs-import-test.js

@@ -1,10 +1,10 @@
 import * as HandlebarsViaImport from 'handlebars';
 const HandlebarsViaRequire = require('handlebars');
-import {assertEquals} from './lib/assert';
+import { assertEquals } from './lib/assert';
 
 HandlebarsViaImport.registerHelper('loud', function(text) {
-    return text.toUpperCase();
+  return text.toUpperCase();
 });
 
 const template = HandlebarsViaRequire.compile('Author: {{loud author}}');
-assertEquals(template({author: 'Yehuda'}), 'Author: YEHUDA');
+assertEquals(template({ author: 'Yehuda' }), 'Author: YEHUDA');

integration-testing/webpack-test/src/handlebars-wildcard-import-pre-4.2-test.js

@@ -1,6 +1,6 @@
 import * as Handlebars from 'handlebars/dist/handlebars';
 
-import {assertEquals} from './lib/assert';
+import { assertEquals } from './lib/assert';
 
 const template = Handlebars.compile('Author: {{author}}');
-assertEquals(template({author: 'Yehuda'}), 'Author: Yehuda');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-wildcard-import-test.js

@@ -1,5 +1,5 @@
 import * as Handlebars from 'handlebars';
-import {assertEquals} from './lib/assert';
+import { assertEquals } from './lib/assert';
 
 const template = Handlebars.compile('Author: {{author}}');
-assertEquals(template({author: 'Yehuda'}), 'Author: Yehuda');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/lib/assert.js

@@ -1,5 +1,5 @@
 export function assertEquals(actual, expected) {
-    if (actual !== expected) {
-        throw new Error(`Expected "${actual}" to equal "${expected}"`);
-    }
+  if (actual !== expected) {
+    throw new Error(`Expected "${actual}" to equal "${expected}"`);
+  }
 }

integration-testing/webpack-test/webpack.config.js

@@ -3,20 +3,18 @@ const fs = require('fs');
 const testFiles = fs.readdirSync('src');
 const entryPoints = {};
 testFiles
-    .filter(file => file.match(/-test.js$/))
-    .forEach(file => {
-        entryPoints[file] = `./src/${file}`;
-    });
+  .filter(file => file.match(/-test.js$/))
+  .forEach(file => {
+    entryPoints[file] = `./src/${file}`;
+  });
 
 module.exports = {
-    entry: entryPoints,
-    output: {
-        filename: '[name]',
-        path: __dirname + '/dist'
-    },
-    module: {
-        rules: [
-            {test: /\.handlebars$/, loader: 'handlebars-loader'}
-        ]
-    }
+  entry: entryPoints,
+  output: {
+    filename: '[name]',
+    path: __dirname + '/dist'
+  },
+  module: {
+    rules: [{ test: /\.handlebars$/, loader: 'handlebars-loader' }]
+  }
 };

lib/handlebars.js

@@ -2,7 +2,11 @@ import runtime from './handlebars.runtime';
 
 // Compiler imports
 import AST from './handlebars/compiler/ast';
-import { parser as Parser, parse, parseWithoutProcessing } from './handlebars/compiler/base';
+import {
+  parser as Parser,
+  parse,
+  parseWithoutProcessing
+} from './handlebars/compiler/base';
 import { Compiler, compile, precompile } from './handlebars/compiler/compiler';
 import JavaScriptCompiler from './handlebars/compiler/javascript-compiler';
 import Visitor from './handlebars/compiler/visitor';

lib/handlebars/base.js

@@ -1,10 +1,11 @@
-import {createFrame, extend, toString} from './utils';
+import { createFrame, extend, toString } from './utils';
 import Exception from './exception';
-import {registerDefaultHelpers} from './helpers';
-import {registerDefaultDecorators} from './decorators';
+import { registerDefaultHelpers } from './helpers';
+import { registerDefaultDecorators } from './decorators';
 import logger from './logger';
+import { resetLoggedProperties } from './internal/proto-access';
 
-export const VERSION = '4.5.1';
+export const VERSION = '4.7.4';
 export const COMPILER_REVISION = 8;
 export const LAST_COMPATIBLE_COMPILER_REVISION = 7;
 
@@ -38,7 +39,9 @@ HandlebarsEnvironment.prototype = {
 
   registerHelper: function(name, fn) {
     if (toString.call(name) === objectType) {
-      if (fn) { throw new Exception('Arg not supported with multiple helpers'); }
+      if (fn) {
+        throw new Exception('Arg not supported with multiple helpers');
+      }
       extend(this.helpers, name);
     } else {
       this.helpers[name] = fn;
@@ -53,7 +56,9 @@ HandlebarsEnvironment.prototype = {
       extend(this.partials, name);
     } else {
       if (typeof partial === 'undefined') {
-        throw new Exception(`Attempting to register a partial called "${name}" as undefined`);
+        throw new Exception(
+          `Attempting to register a partial called "${name}" as undefined`
+        );
       }
       this.partials[name] = partial;
     }
@@ -64,17 +69,26 @@ HandlebarsEnvironment.prototype = {
 
   registerDecorator: function(name, fn) {
     if (toString.call(name) === objectType) {
-      if (fn) { throw new Exception('Arg not supported with multiple decorators'); }
+      if (fn) {
+        throw new Exception('Arg not supported with multiple decorators');
+      }
       extend(this.decorators, name);
     } else {
       this.decorators[name] = fn;
     }
   },
   unregisterDecorator: function(name) {
     delete this.decorators[name];
+  },
+  /**
+   * Reset the memory of illegal property accesses that have already been logged.
+   * @deprecated should only be used in handlebars test-cases
+   */
+  resetLoggedPropertyAccesses() {
+    resetLoggedProperties();
   }
 };
 
 export let log = logger.log;
 
-export {createFrame, logger};
+export { createFrame, logger };

lib/handlebars/compiler/ast.js

@@ -5,24 +5,28 @@ let AST = {
     // * it is an eligible helper, and
     // * it has at least one parameter or hash segment
     helperExpression: function(node) {
-      return (node.type === 'SubExpression')
-          || ((node.type === 'MustacheStatement' || node.type === 'BlockStatement')
-            && !!((node.params && node.params.length) || node.hash));
+      return (
+        node.type === 'SubExpression' ||
+        ((node.type === 'MustacheStatement' ||
+          node.type === 'BlockStatement') &&
+          !!((node.params && node.params.length) || node.hash))
+      );
     },
 
     scopedId: function(path) {
-      return (/^\.|this\b/).test(path.original);
+      return /^\.|this\b/.test(path.original);
     },
 
     // an ID is simple if it only has one part, and that part is not
     // `..` or `this`.
     simpleId: function(path) {
-      return path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth;
+      return (
+        path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth
+      );
     }
   }
 };
 
-
 // Must be exported as an object rather than the root of the module as the jison lexer
 // must modify the object to operate properly.
 export default AST;

lib/handlebars/compiler/base.js

@@ -10,7 +10,9 @@ extend(yy, Helpers);
 
 export function parseWithoutProcessing(input, options) {
   // Just return if an already-compiled AST was passed in.
-  if (input.type === 'Program') { return input; }
+  if (input.type === 'Program') {
+    return input;
+  }
 
   parser.yy = yy;
 

lib/handlebars/compiler/code-gen.js

@@ -1,5 +1,5 @@
 /* global define */
-import {isArray} from '../utils';
+import { isArray } from '../utils';
 
 let SourceNode;
 
@@ -38,15 +38,14 @@ if (!SourceNode) {
       this.src = chunks + this.src;
     },
     toStringWithSourceMap: function() {
-      return {code: this.toString()};
+      return { code: this.toString() };
     },
     toString: function() {
       return this.src;
     }
   };
 }
 
-
 function castChunk(chunk, codeGen, loc) {
   if (isArray(chunk)) {
     let ret = [];
@@ -62,7 +61,6 @@ function castChunk(chunk, codeGen, loc) {
   return chunk;
 }
 
-
 function CodeGen(srcFile) {
   this.srcFile = srcFile;
   this.source = [];
@@ -94,17 +92,22 @@ CodeGen.prototype = {
   },
 
   empty: function() {
-    let loc = this.currentLocation || {start: {}};
+    let loc = this.currentLocation || { start: {} };
     return new SourceNode(loc.start.line, loc.start.column, this.srcFile);
   },
-  wrap: function(chunk, loc = this.currentLocation || {start: {}}) {
+  wrap: function(chunk, loc = this.currentLocation || { start: {} }) {
     if (chunk instanceof SourceNode) {
       return chunk;
     }
 
     chunk = castChunk(chunk, this, loc);
 
-    return new SourceNode(loc.start.line, loc.start.column, this.srcFile, chunk);
+    return new SourceNode(
+      loc.start.line,
+      loc.start.column,
+      this.srcFile,
+      chunk
+    );
   },
 
   functionCall: function(fn, type, params) {
@@ -113,34 +116,35 @@ CodeGen.prototype = {
   },
 
   quotedString: function(str) {
-    return '"' + (str + '')
-      .replace(/\\/g, '\\\\')
-      .replace(/"/g, '\\"')
-      .replace(/\n/g, '\\n')
-      .replace(/\r/g, '\\r')
-      .replace(/\u2028/g, '\\u2028') // Per Ecma-262 7.3 + 7.8.4
-      .replace(/\u2029/g, '\\u2029') + '"';
+    return (
+      '"' +
+      (str + '')
+        .replace(/\\/g, '\\\\')
+        .replace(/"/g, '\\"')
+        .replace(/\n/g, '\\n')
+        .replace(/\r/g, '\\r')
+        .replace(/\u2028/g, '\\u2028') // Per Ecma-262 7.3 + 7.8.4
+        .replace(/\u2029/g, '\\u2029') +
+      '"'
+    );
   },
 
   objectLiteral: function(obj) {
     let pairs = [];
 
-    for (let key in obj) {
-      if (obj.hasOwnProperty(key)) {
-        let value = castChunk(obj[key], this);
-        if (value !== 'undefined') {
-          pairs.push([this.quotedString(key), ':', value]);
-        }
+    Object.keys(obj).forEach(key => {
+      let value = castChunk(obj[key], this);
+      if (value !== 'undefined') {
+        pairs.push([this.quotedString(key), ':', value]);
       }
-    }
+    });
 
     let ret = this.generateList(pairs);
     ret.prepend('{');
     ret.add('}');
     return ret;
   },
 
-
   generateList: function(entries) {
     let ret = this.empty();
 
@@ -165,4 +169,3 @@ CodeGen.prototype = {
 };
 
 export default CodeGen;
-

lib/handlebars/compiler/compiler.js

@@ -1,7 +1,7 @@
 /* eslint-disable new-cap */
 
 import Exception from '../exception';
-import {isArray, indexOf, extend} from '../utils';
+import { isArray, indexOf, extend } from '../utils';
 import AST from './ast';
 
 const slice = [].slice;
@@ -24,8 +24,11 @@ Compiler.prototype = {
 
     for (let i = 0; i < len; i++) {
       let opcode = this.opcodes[i],
-          otherOpcode = other.opcodes[i];
-      if (opcode.opcode !== otherOpcode.opcode || !argEquals(opcode.args, otherOpcode.args)) {
+        otherOpcode = other.opcodes[i];
+      if (
+        opcode.opcode !== otherOpcode.opcode ||
+        !argEquals(opcode.args, otherOpcode.args)
+      ) {
         return false;
       }
     }
@@ -54,34 +57,28 @@ Compiler.prototype = {
 
     options.blockParams = options.blockParams || [];
 
-    // These changes will propagate to the other compiler components
-    let knownHelpers = options.knownHelpers;
-    options.knownHelpers = {
-      'helperMissing': true,
-      'blockHelperMissing': true,
-      'each': true,
-      'if': true,
-      'unless': true,
-      'with': true,
-      'log': true,
-      'lookup': true
-    };
-    if (knownHelpers) {
-      // the next line should use "Object.keys", but the code has been like this a long time and changing it, might
-      // cause backwards-compatibility issues... It's an old library...
-      // eslint-disable-next-line guard-for-in
-      for (let name in knownHelpers) {
-          this.options.knownHelpers[name] = knownHelpers[name];
-      }
-    }
+    options.knownHelpers = extend(
+      Object.create(null),
+      {
+        helperMissing: true,
+        blockHelperMissing: true,
+        each: true,
+        if: true,
+        unless: true,
+        with: true,
+        log: true,
+        lookup: true
+      },
+      options.knownHelpers
+    );
 
     return this.accept(program);
   },
 
   compileProgram: function(program) {
     let childCompiler = new this.compiler(), // eslint-disable-line new-cap
-        result = childCompiler.compile(program, this.options),
-        guid = this.guid++;
+      result = childCompiler.compile(program, this.options),
+      guid = this.guid++;
 
     this.usePartial = this.usePartial || result.usePartial;
 
@@ -107,7 +104,7 @@ Compiler.prototype = {
     this.options.blockParams.unshift(program.blockParams);
 
     let body = program.body,
-        bodyLength = body.length;
+      bodyLength = body.length;
     for (let i = 0; i < bodyLength; i++) {
       this.accept(body[i]);
     }
@@ -124,7 +121,7 @@ Compiler.prototype = {
     transformLiteralToPath(block);
 
     let program = block.program,
-        inverse = block.inverse;
+      inverse = block.inverse;
 
     program = program && this.compileProgram(program);
     inverse = inverse && this.compileProgram(inverse);
@@ -159,7 +156,7 @@ Compiler.prototype = {
   DecoratorBlock(decorator) {
     let program = decorator.program && this.compileProgram(decorator.program);
     let params = this.setupFullMustacheParams(decorator, program, undefined),
-        path = decorator.path;
+      path = decorator.path;
 
     this.useDecorators = true;
     this.opcode('registerDecorator', params.length, path.original);
@@ -175,17 +172,20 @@ Compiler.prototype = {
 
     let params = partial.params;
     if (params.length > 1) {
-      throw new Exception('Unsupported number of partial arguments: ' + params.length, partial);
+      throw new Exception(
+        'Unsupported number of partial arguments: ' + params.length,
+        partial
+      );
     } else if (!params.length) {
       if (this.options.explicitPartialContext) {
         this.opcode('pushLiteral', 'undefined');
       } else {
-        params.push({type: 'PathExpression', parts: [], depth: 0});
+        params.push({ type: 'PathExpression', parts: [], depth: 0 });
       }
     }
 
     let partialName = partial.name.original,
-        isDynamic = partial.name.type === 'SubExpression';
+      isDynamic = partial.name.type === 'SubExpression';
     if (isDynamic) {
       this.accept(partial.name);
     }
@@ -218,7 +218,6 @@ Compiler.prototype = {
     this.DecoratorBlock(decorator);
   },
 
-
   ContentStatement: function(content) {
     if (content.value) {
       this.opcode('appendContent', content.value);
@@ -241,8 +240,8 @@ Compiler.prototype = {
   },
   ambiguousSexpr: function(sexpr, program, inverse) {
     let path = sexpr.path,
-        name = path.parts[0],
-        isBlock = program != null || inverse != null;
+      name = path.parts[0],
+      isBlock = program != null || inverse != null;
 
     this.opcode('getContext', path.depth);
 
@@ -264,19 +263,27 @@ Compiler.prototype = {
 
   helperSexpr: function(sexpr, program, inverse) {
     let params = this.setupFullMustacheParams(sexpr, program, inverse),
-        path = sexpr.path,
-        name = path.parts[0];
+      path = sexpr.path,
+      name = path.parts[0];
 
     if (this.options.knownHelpers[name]) {
       this.opcode('invokeKnownHelper', params.length, name);
     } else if (this.options.knownHelpersOnly) {
-      throw new Exception('You specified knownHelpersOnly, but used the unknown helper ' + name, sexpr);
+      throw new Exception(
+        'You specified knownHelpersOnly, but used the unknown helper ' + name,
+        sexpr
+      );
     } else {
       path.strict = true;
       path.falsy = true;
 
       this.accept(path);
-      this.opcode('invokeHelper', params.length, path.original, AST.helpers.simpleId(path));
+      this.opcode(
+        'invokeHelper',
+        params.length,
+        path.original,
+        AST.helpers.simpleId(path)
+      );
     }
   },
 
@@ -285,8 +292,8 @@ Compiler.prototype = {
     this.opcode('getContext', path.depth);
 
     let name = path.parts[0],
-        scoped = AST.helpers.scopedId(path),
-        blockParamId = !path.depth && !scoped && this.blockParamIndex(name);
+      scoped = AST.helpers.scopedId(path),
+      blockParamId = !path.depth && !scoped && this.blockParamIndex(name);
 
     if (blockParamId) {
       this.opcode('lookupBlockParam', blockParamId, path.parts);
@@ -297,7 +304,13 @@ Compiler.prototype = {
       this.options.data = true;
       this.opcode('lookupData', path.depth, path.parts, path.strict);
     } else {
-      this.opcode('lookupOnContext', path.parts, path.falsy, path.strict, scoped);
+      this.opcode(
+        'lookupOnContext',
+        path.parts,
+        path.falsy,
+        path.strict,
+        scoped
+      );
     }
   },
 
@@ -323,8 +336,8 @@ Compiler.prototype = {
 
   Hash: function(hash) {
     let pairs = hash.pairs,
-        i = 0,
-        l = pairs.length;
+      i = 0,
+      l = pairs.length;
 
     this.opcode('pushHash');
 
@@ -339,7 +352,11 @@ Compiler.prototype = {
 
   // HELPERS
   opcode: function(name) {
-    this.opcodes.push({ opcode: name, args: slice.call(arguments, 1), loc: this.sourceNode[0].loc });
+    this.opcodes.push({
+      opcode: name,
+      args: slice.call(arguments, 1),
+      loc: this.sourceNode[0].loc
+    });
   },
 
   addDepth: function(depth) {
@@ -368,8 +385,7 @@ Compiler.prototype = {
     // An eligible helper is one that does not have a complex path, i.e. `this.foo`, `../foo` etc.
     if (isEligible && !isHelper) {
       let name = sexpr.path.parts[0],
-          options = this.options;
-
+        options = this.options;
       if (options.knownHelpers[name]) {
         isHelper = true;
       } else if (options.knownHelpersOnly) {
@@ -397,9 +413,7 @@ Compiler.prototype = {
 
     if (this.stringParams) {
       if (value.replace) {
-        value = value
-            .replace(/^(\.?\.\/)*/g, '')
-            .replace(/\//g, '.');
+        value = value.replace(/^(\.?\.\/)*/g, '').replace(/\//g, '.');
       }
 
       if (val.depth) {
@@ -417,7 +431,7 @@ Compiler.prototype = {
       if (this.trackIds) {
         let blockParamIndex;
         if (val.parts && !AST.helpers.scopedId(val) && !val.depth) {
-           blockParamIndex = this.blockParamIndex(val.parts[0]);
+          blockParamIndex = this.blockParamIndex(val.parts[0]);
         }
         if (blockParamIndex) {
           let blockParamChild = val.parts.slice(1).join('.');
@@ -426,9 +440,9 @@ Compiler.prototype = {
           value = val.original || value;
           if (value.replace) {
             value = value
-                .replace(/^this(?:\.|$)/, '')
-                .replace(/^\.\//, '')
-                .replace(/^\.$/, '');
+              .replace(/^this(?:\.|$)/, '')
+              .replace(/^\.\//, '')
+              .replace(/^\.$/, '');
           }
 
           this.opcode('pushId', val.type, value);
@@ -455,9 +469,13 @@ Compiler.prototype = {
   },
 
   blockParamIndex: function(name) {
-    for (let depth = 0, len = this.options.blockParams.length; depth < len; depth++) {
+    for (
+      let depth = 0, len = this.options.blockParams.length;
+      depth < len;
+      depth++
+    ) {
       let blockParams = this.options.blockParams[depth],
-          param = blockParams && indexOf(blockParams, name);
+        param = blockParams && indexOf(blockParams, name);
       if (blockParams && param >= 0) {
         return [depth, param];
       }
@@ -466,8 +484,14 @@ Compiler.prototype = {
 };
 
 export function precompile(input, options, env) {
-  if (input == null || (typeof input !== 'string' && input.type !== 'Program')) {
-    throw new Exception('You must pass a string or Handlebars AST to Handlebars.precompile. You passed ' + input);
+  if (
+    input == null ||
+    (typeof input !== 'string' && input.type !== 'Program')
+  ) {
+    throw new Exception(
+      'You must pass a string or Handlebars AST to Handlebars.precompile. You passed ' +
+        input
+    );
   }
 
   options = options || {};
@@ -479,13 +503,19 @@ export function precompile(input, options, env) {
   }
 
   let ast = env.parse(input, options),
-      environment = new env.Compiler().compile(ast, options);
+    environment = new env.Compiler().compile(ast, options);
   return new env.JavaScriptCompiler().compile(environment, options);
 }
 
 export function compile(input, options = {}, env) {
-  if (input == null || (typeof input !== 'string' && input.type !== 'Program')) {
-    throw new Exception('You must pass a string or Handlebars AST to Handlebars.compile. You passed ' + input);
+  if (
+    input == null ||
+    (typeof input !== 'string' && input.type !== 'Program')
+  ) {
+    throw new Exception(
+      'You must pass a string or Handlebars AST to Handlebars.compile. You passed ' +
+        input
+    );
   }
 
   options = extend({}, options);
@@ -500,8 +530,13 @@ export function compile(input, options = {}, env) {
 
   function compileInput() {
     let ast = env.parse(input, options),
-        environment = new env.Compiler().compile(ast, options),
-        templateSpec = new env.JavaScriptCompiler().compile(environment, options, undefined, true);
+      environment = new env.Compiler().compile(ast, options),
+      templateSpec = new env.JavaScriptCompiler().compile(
+        environment,
+        options,
+        undefined,
+        true
+      );
     return env.template(templateSpec);
   }
 

lib/handlebars/compiler/helpers.js

@@ -4,9 +4,12 @@ function validateClose(open, close) {
   close = close.path ? close.path.original : close;
 
   if (open.path.original !== close) {
-    let errorNode = {loc: open.path.loc};
+    let errorNode = { loc: open.path.loc };
 
-    throw new Exception(open.path.original + " doesn't match " + close, errorNode);
+    throw new Exception(
+      open.path.original + " doesn't match " + close,
+      errorNode
+    );
   }
 }
 
@@ -38,27 +41,26 @@ export function stripFlags(open, close) {
 }
 
 export function stripComment(comment) {
-  return comment.replace(/^\{\{~?!-?-?/, '')
-                .replace(/-?-?~?\}\}$/, '');
+  return comment.replace(/^\{\{~?!-?-?/, '').replace(/-?-?~?\}\}$/, '');
 }
 
 export function preparePath(data, parts, loc) {
   loc = this.locInfo(loc);
 
   let original = data ? '@' : '',
-      dig = [],
-      depth = 0;
+    dig = [],
+    depth = 0;
 
   for (let i = 0, l = parts.length; i < l; i++) {
     let part = parts[i].part,
-        // If we have [] syntax then we do not treat path references as operators,
-        // i.e. foo.[this] resolves to approximately context.foo['this']
-        isLiteral = parts[i].original !== part;
+      // If we have [] syntax then we do not treat path references as operators,
+      // i.e. foo.[this] resolves to approximately context.foo['this']
+      isLiteral = parts[i].original !== part;
     original += (parts[i].separator || '') + part;
 
     if (!isLiteral && (part === '..' || part === '.' || part === 'this')) {
       if (dig.length > 0) {
-        throw new Exception('Invalid path: ' + original, {loc});
+        throw new Exception('Invalid path: ' + original, { loc });
       } else if (part === '..') {
         depth++;
       }
@@ -80,9 +82,9 @@ export function preparePath(data, parts, loc) {
 export function prepareMustache(path, params, hash, open, strip, locInfo) {
   // Must use charAt to support IE pre-10
   let escapeFlag = open.charAt(3) || open.charAt(2),
-      escaped = escapeFlag !== '{' && escapeFlag !== '&';
+    escaped = escapeFlag !== '{' && escapeFlag !== '&';
 
-  let decorator = (/\*/.test(open));
+  let decorator = /\*/.test(open);
   return {
     type: decorator ? 'Decorator' : 'MustacheStatement',
     path,
@@ -118,21 +120,30 @@ export function prepareRawBlock(openRawBlock, contents, close, locInfo) {
   };
 }
 
-export function prepareBlock(openBlock, program, inverseAndProgram, close, inverted, locInfo) {
+export function prepareBlock(
+  openBlock,
+  program,
+  inverseAndProgram,
+  close,
+  inverted,
+  locInfo
+) {
   if (close && close.path) {
     validateClose(openBlock, close);
   }
 
-  let decorator = (/\*/.test(openBlock.open));
+  let decorator = /\*/.test(openBlock.open);
 
   program.blockParams = openBlock.blockParams;
 
-  let inverse,
-      inverseStrip;
+  let inverse, inverseStrip;
 
   if (inverseAndProgram) {
     if (decorator) {
-      throw new Exception('Unexpected inverse block on decorator', inverseAndProgram);
+      throw new Exception(
+        'Unexpected inverse block on decorator',
+        inverseAndProgram
+      );
     }
 
     if (inverseAndProgram.chain) {
@@ -166,7 +177,7 @@ export function prepareBlock(openBlock, program, inverseAndProgram, close, inver
 export function prepareProgram(statements, loc) {
   if (!loc && statements.length) {
     const firstLoc = statements[0].loc,
-          lastLoc = statements[statements.length - 1].loc;
+      lastLoc = statements[statements.length - 1].loc;
 
     /* istanbul ignore else */
     if (firstLoc && lastLoc) {
@@ -192,7 +203,6 @@ export function prepareProgram(statements, loc) {
   };
 }
 
-
 export function preparePartialBlock(open, program, close, locInfo) {
   validateClose(open, close);
 
@@ -207,4 +217,3 @@ export function preparePartialBlock(open, program, close, locInfo) {
     loc: this.locInfo(locInfo)
   };
 }
-

lib/handlebars/compiler/printer.js

@@ -24,13 +24,14 @@ PrintVisitor.prototype.pad = function(string) {
 
 PrintVisitor.prototype.Program = function(program) {
   let out = '',
-      body = program.body,
-      i, l;
+    body = program.body,
+    i,
+    l;
 
   if (program.blockParams) {
     let blockParams = 'BLOCK PARAMS: [';
     for (i = 0, l = program.blockParams.length; i < l; i++) {
-       blockParams += ' ' + program.blockParams[i];
+      blockParams += ' ' + program.blockParams[i];
     }
     blockParams += ' ]';
     out += this.pad(blockParams);
@@ -52,11 +53,14 @@ PrintVisitor.prototype.Decorator = function(mustache) {
   return this.pad('{{ DIRECTIVE ' + this.SubExpression(mustache) + ' }}');
 };
 
-PrintVisitor.prototype.BlockStatement =
-PrintVisitor.prototype.DecoratorBlock = function(block) {
+PrintVisitor.prototype.BlockStatement = PrintVisitor.prototype.DecoratorBlock = function(
+  block
+) {
   let out = '';
 
-  out += this.pad((block.type === 'DecoratorBlock' ? 'DIRECTIVE ' : '') + 'BLOCK:');
+  out += this.pad(
+    (block.type === 'DecoratorBlock' ? 'DIRECTIVE ' : '') + 'BLOCK:'
+  );
   this.padding++;
   out += this.pad(this.SubExpression(block));
   if (block.program) {
@@ -66,12 +70,16 @@ PrintVisitor.prototype.DecoratorBlock = function(block) {
     this.padding--;
   }
   if (block.inverse) {
-    if (block.program) { this.padding++; }
+    if (block.program) {
+      this.padding++;
+    }
     out += this.pad('{{^}}');
     this.padding++;
     out += this.accept(block.inverse);
     this.padding--;
-    if (block.program) { this.padding--; }
+    if (block.program) {
+      this.padding--;
+    }
   }
   this.padding--;
 
@@ -115,8 +123,8 @@ PrintVisitor.prototype.CommentStatement = function(comment) {
 
 PrintVisitor.prototype.SubExpression = function(sexpr) {
   let params = sexpr.params,
-      paramStrings = [],
-      hash;
+    paramStrings = [],
+    hash;
 
   for (let i = 0, l = params.length; i < l; i++) {
     paramStrings.push(this.accept(params[i]));
@@ -134,7 +142,6 @@ PrintVisitor.prototype.PathExpression = function(id) {
   return (id.data ? '@' : '') + 'PATH:' + path;
 };
 
-
 PrintVisitor.prototype.StringLiteral = function(string) {
   return '"' + string.value + '"';
 };
@@ -157,7 +164,7 @@ PrintVisitor.prototype.NullLiteral = function() {
 
 PrintVisitor.prototype.Hash = function(hash) {
   let pairs = hash.pairs,
-      joinedPairs = [];
+    joinedPairs = [];
 
   for (let i = 0, l = pairs.length; i < l; i++) {
     joinedPairs.push(this.accept(pairs[i]));

lib/handlebars/compiler/visitor.js

@@ -15,7 +15,14 @@ Visitor.prototype = {
       // Hacky sanity check: This may have a few false positives for type for the helper
       // methods but will generally do the right thing without a lot of overhead.
       if (value && !Visitor.prototype[value.type]) {
-        throw new Exception('Unexpected node type "' + value.type + '" found when accepting ' + name + ' on ' + node.type);
+        throw new Exception(
+          'Unexpected node type "' +
+            value.type +
+            '" found when accepting ' +
+            name +
+            ' on ' +
+            node.type
+        );
       }
       node[name] = value;
     }

lib/handlebars/compiler/whitespace-control.js

@@ -14,18 +14,18 @@ WhitespaceControl.prototype.Program = function(program) {
   let body = program.body;
   for (let i = 0, l = body.length; i < l; i++) {
     let current = body[i],
-        strip = this.accept(current);
+      strip = this.accept(current);
 
     if (!strip) {
       continue;
     }
 
     let _isPrevWhitespace = isPrevWhitespace(body, i, isRoot),
-        _isNextWhitespace = isNextWhitespace(body, i, isRoot),
-
-        openStandalone = strip.openStandalone && _isPrevWhitespace,
-        closeStandalone = strip.closeStandalone && _isNextWhitespace,
-        inlineStandalone = strip.inlineStandalone && _isPrevWhitespace && _isNextWhitespace;
+      _isNextWhitespace = isNextWhitespace(body, i, isRoot),
+      openStandalone = strip.openStandalone && _isPrevWhitespace,
+      closeStandalone = strip.closeStandalone && _isNextWhitespace,
+      inlineStandalone =
+        strip.inlineStandalone && _isPrevWhitespace && _isNextWhitespace;
 
     if (strip.close) {
       omitRight(body, i, true);
@@ -41,7 +41,7 @@ WhitespaceControl.prototype.Program = function(program) {
         // If we are on a standalone node, save the indent info for partials
         if (current.type === 'PartialStatement') {
           // Pull out the whitespace from the final line
-          current.indent = (/([ \t]+$)/).exec(body[i - 1].original)[1];
+          current.indent = /([ \t]+$)/.exec(body[i - 1].original)[1];
         }
       }
     }
@@ -62,17 +62,17 @@ WhitespaceControl.prototype.Program = function(program) {
   return program;
 };
 
-WhitespaceControl.prototype.BlockStatement =
-WhitespaceControl.prototype.DecoratorBlock =
-WhitespaceControl.prototype.PartialBlockStatement = function(block) {
+WhitespaceControl.prototype.BlockStatement = WhitespaceControl.prototype.DecoratorBlock = WhitespaceControl.prototype.PartialBlockStatement = function(
+  block
+) {
   this.accept(block.program);
   this.accept(block.inverse);
 
   // Find the inverse program that is involed with whitespace stripping.
   let program = block.program || block.inverse,
-      inverse = block.program && block.inverse,
-      firstInverse = inverse,
-      lastInverse = inverse;
+    inverse = block.program && block.inverse,
+    firstInverse = inverse,
+    lastInverse = inverse;
 
   if (inverse && inverse.chained) {
     firstInverse = inverse.body[0].program;
@@ -112,9 +112,11 @@ WhitespaceControl.prototype.PartialBlockStatement = function(block) {
     }
 
     // Find standalone else statments
-    if (!this.options.ignoreStandalone
-        && isPrevWhitespace(program.body)
-        && isNextWhitespace(firstInverse.body)) {
+    if (
+      !this.options.ignoreStandalone &&
+      isPrevWhitespace(program.body) &&
+      isNextWhitespace(firstInverse.body)
+    ) {
       omitLeft(program.body);
       omitRight(firstInverse.body);
     }
@@ -125,13 +127,15 @@ WhitespaceControl.prototype.PartialBlockStatement = function(block) {
   return strip;
 };
 
-WhitespaceControl.prototype.Decorator =
-WhitespaceControl.prototype.MustacheStatement = function(mustache) {
+WhitespaceControl.prototype.Decorator = WhitespaceControl.prototype.MustacheStatement = function(
+  mustache
+) {
   return mustache.strip;
 };
 
-WhitespaceControl.prototype.PartialStatement =
-    WhitespaceControl.prototype.CommentStatement = function(node) {
+WhitespaceControl.prototype.PartialStatement = WhitespaceControl.prototype.CommentStatement = function(
+  node
+) {
   /* istanbul ignore next */
   let strip = node.strip || {};
   return {
@@ -141,7 +145,6 @@ WhitespaceControl.prototype.PartialStatement =
   };
 };
 
-
 function isPrevWhitespace(body, i, isRoot) {
   if (i === undefined) {
     i = body.length;
@@ -150,13 +153,15 @@ function isPrevWhitespace(body, i, isRoot) {
   // Nodes that end with newlines are considered whitespace (but are special
   // cased for strip operations)
   let prev = body[i - 1],
-      sibling = body[i - 2];
+    sibling = body[i - 2];
   if (!prev) {
     return isRoot;
   }
 
   if (prev.type === 'ContentStatement') {
-    return (sibling || !isRoot ? (/\r?\n\s*?$/) : (/(^|\r?\n)\s*?$/)).test(prev.original);
+    return (sibling || !isRoot ? /\r?\n\s*?$/ : /(^|\r?\n)\s*?$/).test(
+      prev.original
+    );
   }
 }
 function isNextWhitespace(body, i, isRoot) {
@@ -165,13 +170,15 @@ function isNextWhitespace(body, i, isRoot) {
   }
 
   let next = body[i + 1],
-      sibling = body[i + 2];
+    sibling = body[i + 2];
   if (!next) {
     return isRoot;
   }
 
   if (next.type === 'ContentStatement') {
-    return (sibling || !isRoot ? (/^\s*?\r?\n/) : (/^\s*?(\r?\n|$)/)).test(next.original);
+    return (sibling || !isRoot ? /^\s*?\r?\n/ : /^\s*?(\r?\n|$)/).test(
+      next.original
+    );
   }
 }
 
@@ -184,12 +191,19 @@ function isNextWhitespace(body, i, isRoot) {
 // content is met.
 function omitRight(body, i, multiple) {
   let current = body[i == null ? 0 : i + 1];
-  if (!current || current.type !== 'ContentStatement' || (!multiple && current.rightStripped)) {
+  if (
+    !current ||
+    current.type !== 'ContentStatement' ||
+    (!multiple && current.rightStripped)
+  ) {
     return;
   }
 
   let original = current.value;
-  current.value = current.value.replace(multiple ? (/^\s+/) : (/^[ \t]*\r?\n?/), '');
+  current.value = current.value.replace(
+    multiple ? /^\s+/ : /^[ \t]*\r?\n?/,
+    ''
+  );
   current.rightStripped = current.value !== original;
 }
 
@@ -202,13 +216,17 @@ function omitRight(body, i, multiple) {
 // content is met.
 function omitLeft(body, i, multiple) {
   let current = body[i == null ? body.length - 1 : i - 1];
-  if (!current || current.type !== 'ContentStatement' || (!multiple && current.leftStripped)) {
+  if (
+    !current ||
+    current.type !== 'ContentStatement' ||
+    (!multiple && current.leftStripped)
+  ) {
     return;
   }
 
   // We omit the last node if it's whitespace only and not preceded by a non-content node.
   let original = current.value;
-  current.value = current.value.replace(multiple ? (/\s+$/) : (/[ \t]+$/), '');
+  current.value = current.value.replace(multiple ? /\s+$/ : /[ \t]+$/, '');
   current.leftStripped = current.value !== original;
   return current.leftStripped;
 }

lib/handlebars/decorators.js

@@ -3,4 +3,3 @@ import registerInline from './decorators/inline';
 export function registerDefaultDecorators(instance) {
   registerInline(instance);
 }
-

lib/handlebars/decorators/inline.js

@@ -1,4 +1,4 @@
-import {extend} from '../utils';
+import { extend } from '../utils';
 
 export default function(instance) {
   instance.registerDecorator('inline', function(fn, props, container, options) {

lib/handlebars/exception.js

@@ -1,12 +1,20 @@
-
-const errorProps = ['description', 'fileName', 'lineNumber', 'endLineNumber', 'message', 'name', 'number', 'stack'];
+const errorProps = [
+  'description',
+  'fileName',
+  'lineNumber',
+  'endLineNumber',
+  'message',
+  'name',
+  'number',
+  'stack'
+];
 
 function Exception(message, node) {
   let loc = node && node.loc,
-      line,
-      endLineNumber,
-      column,
-      endColumn;
+    line,
+    endLineNumber,
+    column,
+    endColumn;
 
   if (loc) {
     line = loc.start.line;

lib/handlebars/helpers/block-helper-missing.js

@@ -1,9 +1,9 @@
-import {appendContextPath, createFrame, isArray} from '../utils';
+import { appendContextPath, createFrame, isArray } from '../utils';
 
 export default function(instance) {
   instance.registerHelper('blockHelperMissing', function(context, options) {
     let inverse = options.inverse,
-        fn = options.fn;
+      fn = options.fn;
 
     if (context === true) {
       return fn(this);
@@ -22,8 +22,11 @@ export default function(instance) {
     } else {
       if (options.data && options.ids) {
         let data = createFrame(options.data);
-        data.contextPath = appendContextPath(options.data.contextPath, options.name);
-        options = {data: data};
+        data.contextPath = appendContextPath(
+          options.data.contextPath,
+          options.name
+        );
+        options = { data: data };
       }
 
       return fn(context, options);

lib/handlebars/helpers/each.js

@@ -1,4 +1,10 @@
-import {appendContextPath, blockParams, createFrame, isArray, isFunction} from '../utils';
+import {
+  appendContextPath,
+  blockParams,
+  createFrame,
+  isArray,
+  isFunction
+} from '../utils';
 import Exception from '../exception';
 
 export default function(instance) {
@@ -8,17 +14,20 @@ export default function(instance) {
     }
 
     let fn = options.fn,
-        inverse = options.inverse,
-        i = 0,
-        ret = '',
-        data,
-        contextPath;
+      inverse = options.inverse,
+      i = 0,
+      ret = '',
+      data,
+      contextPath;
 
     if (options.data && options.ids) {
-      contextPath = appendContextPath(options.data.contextPath, options.ids[0]) + '.';
+      contextPath =
+        appendContextPath(options.data.contextPath, options.ids[0]) + '.';
     }
 
-    if (isFunction(context)) { context = context.call(this); }
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
 
     if (options.data) {
       data = createFrame(options.data);
@@ -36,10 +45,15 @@ export default function(instance) {
         }
       }
 
-      ret = ret + fn(context[field], {
-        data: data,
-        blockParams: blockParams([context[field], field], [contextPath + field, null])
-      });
+      ret =
+        ret +
+        fn(context[field], {
+          data: data,
+          blockParams: blockParams(
+            [context[field], field],
+            [contextPath + field, null]
+          )
+        });
     }
 
     if (context && typeof context === 'object') {
@@ -62,18 +76,16 @@ export default function(instance) {
       } else {
         let priorKey;
 
-        for (let key in context) {
-          if (context.hasOwnProperty(key)) {
-            // We're running the iterations one step out of sync so we can detect
-            // the last iteration without have to scan the object twice and create
-            // an itermediate keys array.
-            if (priorKey !== undefined) {
-              execIteration(priorKey, i - 1);
-            }
-            priorKey = key;
-            i++;
+        Object.keys(context).forEach(key => {
+          // We're running the iterations one step out of sync so we can detect
+          // the last iteration without have to scan the object twice and create
+          // an itermediate keys array.
+          if (priorKey !== undefined) {
+            execIteration(priorKey, i - 1);
           }
-        }
+          priorKey = key;
+          i++;
+        });
         if (priorKey !== undefined) {
           execIteration(priorKey, i - 1, true);
         }

lib/handlebars/helpers/helper-missing.js

@@ -7,7 +7,9 @@ export default function(instance) {
       return undefined;
     } else {
       // Someone is actually trying to call something, blow up.
-      throw new Exception('Missing helper: "' + arguments[arguments.length - 1].name + '"');
+      throw new Exception(
+        'Missing helper: "' + arguments[arguments.length - 1].name + '"'
+      );
     }
   });
 }

lib/handlebars/helpers/if.js

@@ -3,8 +3,12 @@ import Exception from '../exception';
 
 export default function(instance) {
   instance.registerHelper('if', function(conditional, options) {
-    if (arguments.length != 2) { throw new Exception('#if requires exactly one argument');}
-    if (isFunction(conditional)) { conditional = conditional.call(this); }
+    if (arguments.length != 2) {
+      throw new Exception('#if requires exactly one argument');
+    }
+    if (isFunction(conditional)) {
+      conditional = conditional.call(this);
+    }
 
     // Default behavior is to render the positive path if the value is truthy and not empty.
     // The `includeZero` option may be set to treat the condtional as purely not empty based on the
@@ -17,7 +21,13 @@ export default function(instance) {
   });
 
   instance.registerHelper('unless', function(conditional, options) {
-    if (arguments.length != 2) { throw new Exception('#unless requires exactly one argument');}
-    return instance.helpers['if'].call(this, conditional, {fn: options.inverse, inverse: options.fn, hash: options.hash});
+    if (arguments.length != 2) {
+      throw new Exception('#unless requires exactly one argument');
+    }
+    return instance.helpers['if'].call(this, conditional, {
+      fn: options.inverse,
+      inverse: options.fn,
+      hash: options.hash
+    });
   });
 }

lib/handlebars/helpers/log.js

@@ -1,7 +1,7 @@
 export default function(instance) {
   instance.registerHelper('log', function(/* message, options */) {
     let args = [undefined],
-        options = arguments[arguments.length - 1];
+      options = arguments[arguments.length - 1];
     for (let i = 0; i < arguments.length - 1; i++) {
       args.push(arguments[i]);
     }
@@ -14,6 +14,6 @@ export default function(instance) {
     }
     args[0] = level;
 
-    instance.log(... args);
+    instance.log(...args);
   });
 }

lib/handlebars/helpers/lookup.js

@@ -1,11 +1,9 @@
 export default function(instance) {
-  instance.registerHelper('lookup', function(obj, field) {
+  instance.registerHelper('lookup', function(obj, field, options) {
     if (!obj) {
+      // Note for 5.0: Change to "obj == null" in 5.0
       return obj;
     }
-    if (field === 'constructor' && !obj.propertyIsEnumerable(field)) {
-      return undefined;
-    }
-    return obj[field];
+    return options.lookupProperty(obj, field);
   });
 }

lib/handlebars/helpers/with.js

@@ -1,18 +1,31 @@
-import { appendContextPath, blockParams, createFrame, isEmpty, isFunction } from '../utils';
+import {
+  appendContextPath,
+  blockParams,
+  createFrame,
+  isEmpty,
+  isFunction
+} from '../utils';
 import Exception from '../exception';
 
 export default function(instance) {
   instance.registerHelper('with', function(context, options) {
-    if (arguments.length != 2) { throw new Exception('#with requires exactly one argument');}
-    if (isFunction(context)) { context = context.call(this); }
+    if (arguments.length != 2) {
+      throw new Exception('#with requires exactly one argument');
+    }
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
 
     let fn = options.fn;
 
     if (!isEmpty(context)) {
       let data = options.data;
       if (options.data && options.ids) {
         data = createFrame(options.data);
-        data.contextPath = appendContextPath(options.data.contextPath, options.ids[0]);
+        data.contextPath = appendContextPath(
+          options.data.contextPath,
+          options.ids[0]
+        );
       }
 
       return fn(context, {

lib/handlebars/internal/create-new-lookup-object.js

@@ -0,0 +1,11 @@
+import { extend } from '../utils';
+
+/**
+ * Create a new object with "null"-prototype to avoid truthy results on prototype properties.
+ * The resulting object can be used with "object[property]" to check if a property exists
+ * @param {...object} sources a varargs parameter of source objects that will be merged
+ * @returns {object}
+ */
+export function createNewLookupObject(...sources) {
+  return extend(Object.create(null), ...sources);
+}

lib/handlebars/internal/proto-access.js

@@ -0,0 +1,70 @@
+import { createNewLookupObject } from './create-new-lookup-object';
+import * as logger from '../logger';
+
+const loggedProperties = Object.create(null);
+
+export function createProtoAccessControl(runtimeOptions) {
+  let defaultMethodWhiteList = Object.create(null);
+  defaultMethodWhiteList['constructor'] = false;
+  defaultMethodWhiteList['__defineGetter__'] = false;
+  defaultMethodWhiteList['__defineSetter__'] = false;
+  defaultMethodWhiteList['__lookupGetter__'] = false;
+
+  let defaultPropertyWhiteList = Object.create(null);
+  // eslint-disable-next-line no-proto
+  defaultPropertyWhiteList['__proto__'] = false;
+
+  return {
+    properties: {
+      whitelist: createNewLookupObject(
+        defaultPropertyWhiteList,
+        runtimeOptions.allowedProtoProperties
+      ),
+      defaultValue: runtimeOptions.allowProtoPropertiesByDefault
+    },
+    methods: {
+      whitelist: createNewLookupObject(
+        defaultMethodWhiteList,
+        runtimeOptions.allowedProtoMethods
+      ),
+      defaultValue: runtimeOptions.allowProtoMethodsByDefault
+    }
+  };
+}
+
+export function resultIsAllowed(result, protoAccessControl, propertyName) {
+  if (typeof result === 'function') {
+    return checkWhiteList(protoAccessControl.methods, propertyName);
+  } else {
+    return checkWhiteList(protoAccessControl.properties, propertyName);
+  }
+}
+
+function checkWhiteList(protoAccessControlForType, propertyName) {
+  if (protoAccessControlForType.whitelist[propertyName] !== undefined) {
+    return protoAccessControlForType.whitelist[propertyName] === true;
+  }
+  if (protoAccessControlForType.defaultValue !== undefined) {
+    return protoAccessControlForType.defaultValue;
+  }
+  logUnexpecedPropertyAccessOnce(propertyName);
+  return false;
+}
+
+function logUnexpecedPropertyAccessOnce(propertyName) {
+  if (loggedProperties[propertyName] !== true) {
+    loggedProperties[propertyName] = true;
+    logger.log(
+      'error',
+      `Handlebars: Access has been denied to resolve the property "${propertyName}" because it is not an "own property" of its parent.\n` +
+        `You can add a runtime option to disable the check or this warning:\n` +
+        `See https://handlebarsjs.com/api-reference/runtime-options.html#options-to-control-prototype-access for details`
+    );
+  }
+}
+
+export function resetLoggedProperties() {
+  Object.keys(loggedProperties).forEach(propertyName => {
+    delete loggedProperties[propertyName];
+  });
+}

lib/handlebars/internal/wrapHelper.js

@@ -0,0 +1,13 @@
+export function wrapHelper(helper, transformOptionsFn) {
+  if (typeof helper !== 'function') {
+    // This should not happen, but apparently it does in https://github.com/wycats/handlebars.js/issues/1639
+    // We try to make the wrapper least-invasive by not wrapping it, if the helper is not a function.
+    return helper;
+  }
+  let wrapper = function(/* dynamic arguments */) {
+    const options = arguments[arguments.length - 1];
+    arguments[arguments.length - 1] = transformOptionsFn(options);
+    return helper.apply(this, arguments);
+  };
+  return wrapper;
+}

lib/handlebars/logger.js

@@ -1,4 +1,4 @@
-import {indexOf} from './utils';
+import { indexOf } from './utils';
 
 let logger = {
   methodMap: ['debug', 'info', 'warn', 'error'],
@@ -22,9 +22,13 @@ let logger = {
   log: function(level, ...message) {
     level = logger.lookupLevel(level);
 
-    if (typeof console !== 'undefined' && logger.lookupLevel(logger.level) <= level) {
+    if (
+      typeof console !== 'undefined' &&
+      logger.lookupLevel(logger.level) <= level
+    ) {
       let method = logger.methodMap[level];
-      if (!console[method]) { // eslint-disable-line no-console
+      // eslint-disable-next-line no-console
+      if (!console[method]) {
         method = 'log';
       }
       console[method](...message); // eslint-disable-line no-console

lib/handlebars/no-conflict.js

@@ -1,8 +1,7 @@
-/* global window */
 export default function(Handlebars) {
   /* istanbul ignore next */
   let root = typeof global !== 'undefined' ? global : window,
-      $Handlebars = root.Handlebars;
+    $Handlebars = root.Handlebars;
   /* istanbul ignore next */
   Handlebars.noConflict = function() {
     if (root.Handlebars === Handlebars) {