.editorconfig

@@ -9,5 +9,4 @@ insert_final_newline = true
 trim_trailing_whitespace = true
 
 [*.md]
-insert_final_newline = true
-trim_trailing_whitespace = false
+trim_trailing_whitespace = false

.eslintignore

@@ -1,6 +1,4 @@
-*.snap
-/node_modules
+/coverage
 /dist
-/examples/build
-/coverage/
-/test/fixtures
+/node_modules
+/test/fixtures

.eslintrc.js

@@ -1,11 +1,4 @@
 module.exports = {
   root: true,
-  plugins: ['prettier'],
-  extends: ['@webpack-contrib/eslint-config-webpack'],
-  rules: {
-    'prettier/prettier': [
-      'error',
-      { singleQuote: true, trailingComma: 'es5', arrowParens: 'always' },
-    ],
-  },
+  extends: ['@webpack-contrib/eslint-config-webpack', 'prettier'],
 };

.gitattributes

@@ -1,3 +1,4 @@
 package-lock.json -diff
 * text=auto
 bin/* eol=lf
+yarn.lock -diff

.github/CONTRIBUTING.md

@@ -1,21 +1,21 @@
-## Contributing in @webpack-contrib
+# Contributing in @webpack-contrib
 
-We'd always love contributions to further improve the webpack / webpack-contrib ecosystem! 
+We'd always love contributions to further improve the webpack / webpack-contrib ecosystem!
 Here are the guidelines we'd like you to follow:
 
-* [Questions and Problems](#question)
-* [Issues and Bugs](#issue)
-* [Feature Requests](#feature)
-* [Pull Request Submission Guidelines](#submit-pr)
-* [Commit Message Conventions](#commit)
+- [Questions and Problems](#question)
+- [Issues and Bugs](#issue)
+- [Feature Requests](#feature)
+- [Pull Request Submission Guidelines](#submit-pr)
+- [Commit Message Conventions](#commit)
 
-### <a name="question"></a> Got a Question or Problem?
+## <a name="question"></a> Got a Question or Problem?
 
-Please submit support requests and questions to StackOverflow using the tag [[webpack]](http://stackoverflow.com/tags/webpack). 
-StackOverflow is better suited for this kind of support though you may also inquire in [Webpack Gitter](https://gitter.im/webpack/webpack). 
+Please submit support requests and questions to StackOverflow using the tag [[webpack]](http://stackoverflow.com/tags/webpack).
+StackOverflow is better suited for this kind of support though you may also inquire in [Webpack Gitter](https://gitter.im/webpack/webpack).
 The issue tracker is for bug reports and feature discussions.
 
-### <a name="issue"></a> Found an Issue or Bug?
+## <a name="issue"></a> Found an Issue or Bug?
 
 Before you submit an issue, please search the issue tracker, maybe an issue for your problem already exists and the discussion might inform you of workarounds readily available.
 
@@ -31,13 +31,13 @@ We will be insisting on a minimal reproduce scenario in order to save maintainer
 
 Unfortunately, we are not able to investigate / fix bugs without a minimal reproduction, so if we don't hear back from you we are going to close an issue that doesn't have enough info to be reproduced.
 
-### <a name="feature"></a> Feature Requests?
+## <a name="feature"></a> Feature Requests?
 
-You can *request* a new feature by creating an issue on Github. 
+You can _request_ a new feature by creating an issue on Github.
 
-If you would like to *implement* a new feature, please submit an issue with a proposal for your work `first`, to be sure that particular makes sense for the project.
+If you would like to _implement_ a new feature, please submit an issue with a proposal for your work `first`, to be sure that particular makes sense for the project.
 
-### <a name="submit-pr"></a> Pull Request Submission Guidelines
+## <a name="submit-pr"></a> Pull Request Submission Guidelines
 
 Before you submit your Pull Request (PR) consider the following guidelines:
 
@@ -46,9 +46,9 @@ Before you submit your Pull Request (PR) consider the following guidelines:
 - Fill out our `Pull Request Template`. Your pull request will not be considered if it is ignored.
 - Please sign the `Contributor License Agreement (CLA)` when a pull request is opened. We cannot accept your pull request without this. Make sure you sign with the primary email address associated with your local / github account.
 
-### <a name="commit"></a> Webpack Contrib Commit Conventions
+## <a name="commit"></a> Webpack Contrib Commit Conventions
 
-Each commit message consists of a **header**, a **body** and a **footer**.  The header has a special
+Each commit message consists of a **header**, a **body** and a **footer**. The header has a special
 format that includes a **type**, a **scope** and a **subject**:
 
 ```
@@ -66,48 +66,56 @@ to read on GitHub as well as in various git tools.
 
 The footer should contain a [closing reference to an issue](https://help.github.com/articles/closing-issues-via-commit-messages/) if any.
 
-Examples: 
+Examples:
+
 ```
 docs(readme): update install instructions
 ```
+
 ```
 fix: refer to the `entrypoint` instead of the first `module`
 ```
 
-#### Revert
-If the commit reverts a previous commit, it should begin with `revert: `, followed by the header of the reverted commit. 
+### Revert
+
+If the commit reverts a previous commit, it should begin with `revert:`, followed by the header of the reverted commit.
 In the body it should say: `This reverts commit <hash>.`, where the hash is the SHA of the commit being reverted.
 
-#### Type
+### Type
+
 Must be one of the following:
 
-* **build**: Changes that affect the build system or external dependencies (example scopes: babel, npm)
-* **chore**: Changes that fall outside of build / docs that do not effect source code (example scopes: package, defaults)
-* **ci**: Changes to our CI configuration files and scripts (example scopes: circleci, travis)
-* **docs**: Documentation only changes (example scopes: readme, changelog)
-* **feat**: A new feature
-* **fix**: A bug fix
-* **perf**: A code change that improves performance
-* **refactor**: A code change that neither fixes a bug nor adds a feature
-* **revert**: Used when reverting a committed change
-* **style**: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons)
-* **test**: Addition of or updates to Jest tests
-
-#### Scope
+- **build**: Changes that affect the build system or external dependencies (example scopes: babel, npm)
+- **chore**: Changes that fall outside of build / docs that do not effect source code (example scopes: package, defaults)
+- **ci**: Changes to our CI configuration files and scripts (example scopes: circleci, travis)
+- **docs**: Documentation only changes (example scopes: readme, changelog)
+- **feat**: A new feature
+- **fix**: A bug fix
+- **perf**: A code change that improves performance
+- **refactor**: A code change that neither fixes a bug nor adds a feature
+- **revert**: Used when reverting a committed change
+- **style**: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons)
+- **test**: Addition of or updates to Jest tests
+
+### Scope
+
 The scope is subjective & depends on the `type` see above. A good example would be a change to a particular class / module.
 
-#### Subject
+### Subject
+
 The subject contains a succinct description of the change:
 
-* use the imperative, present tense: "change" not "changed" nor "changes"
-* don't capitalize the first letter
-* no dot (.) at the end
+- use the imperative, present tense: "change" not "changed" nor "changes"
+- don't capitalize the first letter
+- no dot (.) at the end
+
+### Body
 
-#### Body
 Just as in the **subject**, use the imperative, present tense: "change" not "changed" nor "changes".
 The body should include the motivation for the change and contrast this with previous behavior.
 
-#### Footer
+### Footer
+
 The footer should contain any information about **Breaking Changes** and is also the place to
 reference GitHub issues that this commit **Closes**.
 
@@ -116,9 +124,37 @@ reference GitHub issues that this commit **Closes**.
 Example
 
 ```
-BREAKING CHANGE: Updates to `Chunk.mapModules`. 
+BREAKING CHANGE: Updates to `Chunk.mapModules`.
 
 This release is not backwards compatible with `Webpack 2.x` due to breaking changes in webpack/webpack#4764
 Migration: see webpack/webpack#5225
 
 ```
+
+## Testing Your Pull Request
+
+You may have the need to test your changes in a real-world project or dependent
+module. Thankfully, Github provides a means to do this. Add a dependency to the
+`package.json` for such a project as follows:
+
+```json
+{
+  "devDependencies": {
+    "terser-webpack-plugin": "webpack-contrib/terser-webpack-plugin#{id}/head"
+  }
+}
+```
+
+Where `{id}` is the # ID of your Pull Request.
+
+## Contributor License Agreement
+
+When submitting your contribution, a CLA (Contributor License Agreement) bot will come by to verify that you signed the [CLA](https://cla.js.foundation/webpack-contrib/terser-webpack-plugin).
+If it is your first time, it will link you to the right place to sign it.
+However, if you have committed your contributions using an email that is not the same as your email used on GitHub, the CLA bot can't accept your contribution.
+
+Run `git config user.email` to see your Git email, and verify it with [your GitHub email](https://github.com/settings/emails).
+
+## Thanks
+
+For your interest, time, understanding, and for following this simple guide.

.github/FUNDING.yml

@@ -0,0 +1 @@
+open_collective: webpack

.github/ISSUE_TEMPLATE.md

@@ -13,4 +13,4 @@
   existing template types, your issue may be closed as invalid. Our issue
   templates contain fields that help us help you, and without that important
   info, we might as well be ice-skating uphill, carrying a wooly mammoth.
--->
+-->

.github/ISSUE_TEMPLATE/BUG.md

@@ -1,7 +1,6 @@
 ---
 name: 🐛 Bug Report
 about: Something went awry and you'd like to tell us about it.
-
 ---
 
 <!--
@@ -15,11 +14,11 @@ about: Something went awry and you'd like to tell us about it.
   Head to StackOverflow or https://gitter.im/webpack/webpack.
 -->
 
-* Operating System:
-* Node Version:
-* NPM Version:
-* webpack Version:
-* terser-webpack-plugin Version:
+- Operating System:
+- Node Version:
+- NPM Version:
+- webpack Version:
+- terser-webpack-plugin Version:
 
 ### Expected Behavior
 
@@ -32,13 +31,13 @@ about: Something went awry and you'd like to tell us about it.
 ### Code
 
 ```js
-  // webpack.config.js
-  // If your bitchin' code blocks are over 20 lines, please paste a link to a gist
-  // (https://gist.github.com).
+// webpack.config.js
+// If your code blocks are over 20 lines, please paste a link to a gist
+// (https://gist.github.com).
 ```
 
 ```js
-  // additional code, HEY YO remove this block if you don't need it
+// additional code, HEY YO remove this block if you don't need it
 ```
 
 ### How Do We Reproduce?

.github/ISSUE_TEMPLATE/DOCS.md

@@ -1,7 +1,6 @@
 ---
 name: 📚 Documentation
 about: Are the docs lacking or missing something? Do they need some new 🔥 hotness? Tell us here.
-
 ---
 
 <!--
@@ -26,5 +25,4 @@ Documentation Is:
 
 ### Please Explain in Detail...
 
-
-### Your Proposal for Changes
+### Your Proposal for Changes

.github/ISSUE_TEMPLATE/FEATURE.md

@@ -1,7 +1,6 @@
 ---
 name: ✨ Feature Request
 about: Suggest an idea for this project
-
 ---
 
 <!--
@@ -15,14 +14,12 @@ about: Suggest an idea for this project
   Head to StackOverflow or https://gitter.im/webpack/webpack.
 -->
 
-* Operating System:
-* Node Version:
-* NPM Version:
-* webpack Version:
-* terser-webpack-plugin Version:
+- Operating System:
+- Node Version:
+- NPM Version:
+- webpack Version:
+- terser-webpack-plugin Version:
 
 ### Feature Proposal
 
-
-
 ### Feature Use Case

.github/ISSUE_TEMPLATE/MODIFICATION.md

@@ -1,7 +1,6 @@
 ---
 name: 🔧 Modification Request
 about: Would you like something work differently? Have an alternative approach? This is the template for you.
-
 ---
 
 <!--
@@ -15,19 +14,14 @@ about: Would you like something work differently? Have an alternative approach?
   Head to StackOverflow or https://gitter.im/webpack/webpack.
 -->
 
-* Operating System:
-* Node Version:
-* NPM Version:
-* webpack Version:
-* terser-webpack-plugin Version:
-
+- Operating System:
+- Node Version:
+- NPM Version:
+- webpack Version:
+- terser-webpack-plugin Version:
 
 ### Expected Behavior / Situation
 
-
-
 ### Actual Behavior / Situation
 
-
-
 ### Modification Proposal

.github/ISSUE_TEMPLATE/SUPPORT.md

@@ -1,7 +1,6 @@
 ---
 name: 🆘 Support, Help, and Advice
 about: 👉🏽 Need support, help, or advice? Don't open an issue! Head to StackOverflow or https://gitter.im/webpack/webpack.
-
 ---
 
 Hey there! If you need support, help, or advice then this is not the place to ask.

.github/workflows/nodejs.yml

@@ -0,0 +1,95 @@
+name: terser-webpack-plugin
+
+on:
+  push:
+    branches:
+      - master
+      - next
+  pull_request:
+    branches:
+      - master
+      - next
+
+jobs:
+  lint:
+    name: Lint - ${{ matrix.os }} - Node v${{ matrix.node-version }}
+
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        node-version: [12.x]
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Use Node.js ${{ env.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ env.node-version }}
+
+      - name: Use latest NPM
+        run: sudo npm i -g npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Security audit
+        run: npm run security
+
+      - name: Check commit message
+        uses: wagoid/commitlint-github-action@v1
+
+  test:
+    name: Test - ${{ matrix.os }} - Node v${{ matrix.node-version }}, Webpack ${{ matrix.webpack-version }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        node-version: [10.x, 12.x, 14.x]
+        webpack-version: [latest]
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Setup Git
+        if: matrix.os == 'windows-latest'
+        run: git config --global core.autocrlf input
+
+      - uses: actions/checkout@v2
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Use latest NPM on ubuntu/macos
+        if: matrix.os == 'ubuntu-latest' || matrix.os == 'macos-latest'
+        run: sudo npm i -g npm
+
+      - name: Use latest NPM on windows
+        if: matrix.os == 'windows-latest'
+        run: npm i -g npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Install webpack ${{ matrix.webpack-version }}
+        run: npm i webpack@${{ matrix.webpack-version }}
+
+      - name: Run tests for webpack version ${{ matrix.webpack-version }}
+        run: npm run test:coverage -- --ci
+
+      - name: Submit coverage data to codecov
+        uses: codecov/codecov-action@v1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}

.gitignore

@@ -8,6 +8,7 @@ npm-debug.log*
 /local
 /reports
 /node_modules
+/test/outputs
 
 .DS_Store
 Thumbs.db

.prettierignore

@@ -0,0 +1,5 @@
+/coverage
+/dist
+/node_modules
+/test/fixtures
+CHANGELOG.md

.prettierrc.js

@@ -0,0 +1 @@
+module.exports = { singleQuote: true };

babel.config.js

@@ -0,0 +1,19 @@
+const MIN_BABEL_VERSION = 7;
+
+module.exports = (api) => {
+  api.assertVersion(MIN_BABEL_VERSION);
+  api.cache(true);
+
+  return {
+    presets: [
+      [
+        '@babel/preset-env',
+        {
+          targets: {
+            node: '10.13.0',
+          },
+        },
+      ],
+    ],
+  };
+};

commitlint.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ['@commitlint/config-conventional'],
+};

husky.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  hooks: {
+    'pre-commit': 'lint-staged',
+    'commit-msg': 'commitlint -E HUSKY_GIT_PARAMS',
+  },
+};

jest.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+  testEnvironment: 'node',
+};

lint-staged.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  '*.js': ['eslint --fix', 'prettier --write'],
+  '*.{json,md,yml,css,ts}': ['prettier --write'],
+};

package.json

@@ -1,79 +1,80 @@
 {
   "name": "terser-webpack-plugin",
-  "version": "1.2.1",
+  "version": "5.0.0",
   "description": "Terser plugin for webpack",
   "license": "MIT",
   "repository": "webpack-contrib/terser-webpack-plugin",
   "author": "webpack Contrib Team",
   "homepage": "https://github.com/webpack-contrib/terser-webpack-plugin",
   "bugs": "https://github.com/webpack-contrib/terser-webpack-plugin/issues",
+  "funding": {
+    "type": "opencollective",
+    "url": "https://opencollective.com/webpack"
+  },
   "main": "dist/cjs.js",
   "engines": {
-    "node": ">= 6.9.0"
+    "node": ">= 10.13.0"
   },
   "scripts": {
     "start": "npm run build -- -w",
-    "build": "cross-env NODE_ENV=production babel src -d dist --ignore 'src/**/*.test.js' --copy-files",
     "clean": "del-cli dist",
-    "commitlint": "commitlint",
-    "commitmsg": "commitlint -e $GIT_PARAMS",
-    "lint": "eslint --cache src test",
     "prebuild": "npm run clean",
-    "prepublish": "npm run build",
-    "release": "standard-version",
+    "build": "cross-env NODE_ENV=production babel src -d dist --copy-files",
+    "commitlint": "commitlint --from=master",
     "security": "npm audit",
-    "test": "jest",
-    "test:watch": "jest --watch",
-    "test:coverage": "jest --collectCoverageFrom='src/**/*.js' --coverage",
-    "ci:lint": "npm run lint && npm run security",
-    "ci:test": "npm run test -- --runInBand",
-    "ci:coverage": "npm run test:coverage -- --runInBand",
-    "ci:lint:commits": "commitlint --from=origin/master --to=${CIRCLE_SHA1}",
+    "lint:prettier": "prettier --list-different .",
+    "lint:js": "eslint --cache .",
+    "lint": "npm-run-all -l -p \"lint:**\"",
+    "test:only": "cross-env NODE_ENV=test jest",
+    "test:watch": "npm run test:only -- --watch",
+    "test:coverage": "npm run test:only -- --collectCoverageFrom=\"src/**/*.js\" --coverage",
+    "pretest": "npm run lint",
+    "test": "npm run test:coverage",
+    "prepare": "npm run build",
+    "release": "standard-version",
     "defaults": "webpack-defaults"
   },
   "files": [
     "dist"
   ],
   "peerDependencies": {
-    "webpack": "^4.0.0"
+    "webpack": "^5.1.0"
   },
   "dependencies": {
-    "cacache": "^11.0.2",
-    "find-cache-dir": "^2.0.0",
-    "schema-utils": "^1.0.0",
-    "serialize-javascript": "^1.4.0",
+    "jest-worker": "^26.5.0",
+    "p-limit": "^3.0.2",
+    "schema-utils": "^3.0.0",
+    "serialize-javascript": "^5.0.1",
     "source-map": "^0.6.1",
-    "terser": "^3.8.1",
-    "webpack-sources": "^1.1.0",
-    "worker-farm": "^1.5.2"
+    "terser": "^5.3.5"
   },
   "devDependencies": {
-    "@babel/cli": "^7.1.5",
-    "@babel/core": "^7.1.6",
-    "@babel/polyfill": "^7.0.0",
-    "@babel/preset-env": "^7.1.6",
-    "@commitlint/cli": "^7.0.0",
-    "@commitlint/config-conventional": "^7.0.1",
-    "@webpack-contrib/defaults": "^3.0.0",
+    "@babel/cli": "^7.11.6",
+    "@babel/core": "^7.11.6",
+    "@babel/preset-env": "^7.11.5",
+    "@commitlint/cli": "^11.0.0",
+    "@commitlint/config-conventional": "^11.0.0",
+    "@webpack-contrib/defaults": "^6.3.0",
     "@webpack-contrib/eslint-config-webpack": "^3.0.0",
-    "babel-core": "^7.0.0-bridge.0",
-    "babel-jest": "^23.6.0",
-    "conventional-github-releaser": "^3.1.2",
-    "cross-env": "^5.1.3",
-    "del": "^3.0.0",
-    "del-cli": "^1.1.0",
-    "eslint": "^5.5.0",
-    "eslint-config-webpack": "^1.2.5",
-    "eslint-plugin-import": "^2.8.0",
-    "eslint-plugin-prettier": "^3.0.0",
-    "husky": "^1.2.1",
-    "jest": "^23.5.0",
-    "lint-staged": "^8.1.0",
-    "memory-fs": "^0.4.1",
-    "prettier": "^1.14.0",
-    "standard-version": "^4.3.0",
-    "uglify-js": "^3.4.3",
-    "webpack": "^4.16.3"
+    "babel-jest": "^26.5.2",
+    "copy-webpack-plugin": "^6.2.1",
+    "cross-env": "^7.0.2",
+    "del": "^6.0.0",
+    "del-cli": "^3.0.1",
+    "eslint": "^7.11.0",
+    "eslint-config-prettier": "^6.12.0",
+    "eslint-plugin-import": "^2.22.1",
+    "file-loader": "^6.1.1",
+    "husky": "^4.3.0",
+    "jest": "^26.5.3",
+    "lint-staged": "^10.4.0",
+    "memfs": "^3.2.0",
+    "npm-run-all": "^4.1.5",
+    "prettier": "^2.1.2",
+    "standard-version": "^9.0.0",
+    "uglify-js": "^3.11.2",
+    "webpack": "^5.1.0",
+    "worker-loader": "^3.0.4"
   },
   "keywords": [
     "uglify",
@@ -91,34 +92,5 @@
     "minify",
     "optimize",
     "optimizer"
-  ],
-  "babel": {
-    "presets": [
-      [
-        "@babel/preset-env",
-        {
-          "targets": {
-            "node": "6.9.0"
-          },
-          "useBuiltIns": "usage"
-        }
-      ]
-    ]
-  },
-  "husky": {
-    "hooks": {
-      "pre-commit": "lint-staged"
-    }
-  },
-  "lint-staged": {
-    "*.js": [
-      "eslint --fix",
-      "git add"
-    ]
-  },
-  "commitlint": {
-    "extends": [
-      "@commitlint/config-conventional"
-    ]
-  }
+  ]
 }

src/minify.js

@@ -1,11 +1,7 @@
-/* eslint-disable
-  arrow-body-style
-*/
-import terser from 'terser';
+const { minify: terserMinify } = require('terser');
 
 const buildTerserOptions = ({
   ecma,
-  warnings,
   parse = {},
   compress = {},
   mangle,
@@ -20,8 +16,6 @@ const buildTerserOptions = ({
   /* eslint-enable camelcase */
   safari10,
 } = {}) => ({
-  ecma,
-  warnings,
   parse: { ...parse },
   compress: typeof compress === 'boolean' ? compress : { ...compress },
   // eslint-disable-next-line no-nested-ternary
@@ -32,51 +26,55 @@ const buildTerserOptions = ({
       ? mangle
       : { ...mangle },
   output: {
-    shebang: true,
-    comments: false,
     beautify: false,
-    semicolons: true,
     ...output,
   },
-  module,
   // Ignoring sourceMap from options
   sourceMap: null,
-  toplevel,
-  nameCache,
-  ie8,
+  ecma,
   keep_classnames,
   keep_fnames,
+  ie8,
+  module,
+  nameCache,
   safari10,
+  toplevel,
 });
 
-const buildComments = (options, terserOptions, extractedComments) => {
+function isObject(value) {
+  const type = typeof value;
+
+  return value != null && (type === 'object' || type === 'function');
+}
+
+const buildComments = (extractComments, terserOptions, extractedComments) => {
   const condition = {};
-  const commentsOpts = terserOptions.output.comments;
+  const { comments } = terserOptions.output;
 
-  // Use /^\**!|@preserve|@license|@cc_on/i RegExp
-  if (typeof options.extractComments === 'boolean') {
-    condition.preserve = commentsOpts;
-    condition.extract = /^\**!|@preserve|@license|@cc_on/i;
-  } else if (
-    typeof options.extractComments === 'string' ||
-    options.extractComments instanceof RegExp
-  ) {
-    // extractComments specifies the extract condition and commentsOpts specifies the preserve condition
-    condition.preserve = commentsOpts;
-    condition.extract = options.extractComments;
-  } else if (typeof options.extractComments === 'function') {
-    condition.preserve = commentsOpts;
-    condition.extract = options.extractComments;
+  condition.preserve = typeof comments !== 'undefined' ? comments : false;
+
+  if (typeof extractComments === 'boolean' && extractComments) {
+    condition.extract = 'some';
   } else if (
-    Object.prototype.hasOwnProperty.call(options.extractComments, 'condition')
+    typeof extractComments === 'string' ||
+    extractComments instanceof RegExp
   ) {
-    // Extract condition is given in extractComments.condition
-    condition.preserve = commentsOpts;
-    condition.extract = options.extractComments.condition;
+    condition.extract = extractComments;
+  } else if (typeof extractComments === 'function') {
+    condition.extract = extractComments;
+  } else if (isObject(extractComments)) {
+    condition.extract =
+      typeof extractComments.condition === 'boolean' &&
+      extractComments.condition
+        ? 'some'
+        : typeof extractComments.condition !== 'undefined'
+        ? extractComments.condition
+        : 'some';
   } else {
-    // No extract condition is given. Extract comments that match commentsOpts instead of preserving them
-    condition.preserve = false;
-    condition.extract = commentsOpts;
+    // No extract
+    // Preserve using "commentsOpts" or "some"
+    condition.preserve = typeof comments !== 'undefined' ? comments : 'some';
+    condition.extract = false;
   }
 
   // Ensure that both conditions are functions
@@ -101,8 +99,8 @@ const buildComments = (options, terserOptions, extractedComments) => {
         if (condition[key] === 'some') {
           condition[key] = (astNode, comment) => {
             return (
-              comment.type === 'comment2' &&
-              /^\**!|@preserve|@license|@cc_on/i.test(comment.value)
+              (comment.type === 'comment2' || comment.type === 'comment1') &&
+              /@preserve|@lic|@cc_on|^\**!/i.test(comment.value)
             );
           };
 
@@ -142,45 +140,56 @@ const buildComments = (options, terserOptions, extractedComments) => {
   };
 };
 
-const minify = (options) => {
+async function minify(options) {
   const {
-    file,
+    name,
     input,
     inputSourceMap,
-    extractComments,
     minify: minifyFn,
+    minimizerOptions,
   } = options;
 
   if (minifyFn) {
-    return minifyFn({ [file]: input }, inputSourceMap);
+    return minifyFn({ [name]: input }, inputSourceMap, minimizerOptions);
   }
 
   // Copy terser options
-  const terserOptions = buildTerserOptions(options.terserOptions);
+  const terserOptions = buildTerserOptions(minimizerOptions);
 
-  // Add source map data
+  // Let terser generate a SourceMap
   if (inputSourceMap) {
-    terserOptions.sourceMap = {
-      content: inputSourceMap,
-    };
+    terserOptions.sourceMap = { asObject: true };
   }
 
   const extractedComments = [];
+  const { extractComments } = options;
 
-  if (extractComments) {
-    terserOptions.output.comments = buildComments(
-      options,
-      terserOptions,
-      extractedComments
-    );
-  }
-
-  const { error, map, code, warnings } = terser.minify(
-    { [file]: input },
-    terserOptions
+  terserOptions.output.comments = buildComments(
+    extractComments,
+    terserOptions,
+    extractedComments
   );
 
-  return { error, map, code, warnings, extractedComments };
-};
-
-export default minify;
+  const result = await terserMinify({ [name]: input }, terserOptions);
+
+  return { ...result, extractedComments };
+}
+
+function transform(options) {
+  // 'use strict' => this === undefined (Clean Scope)
+  // Safer for possible security issues, albeit not critical at all here
+  // eslint-disable-next-line no-new-func, no-param-reassign
+  options = new Function(
+    'exports',
+    'require',
+    'module',
+    '__filename',
+    '__dirname',
+    `'use strict'\nreturn ${options}`
+  )(exports, require, module, __filename, __dirname);
+
+  return minify(options);
+}
+
+module.exports.minify = minify;
+module.exports.transform = transform;

src/options.json

@@ -1,86 +1,68 @@
 {
-  "additionalProperties": false,
   "definitions": {
-    "file-conditions": {
+    "Rule": {
+      "description": "Filtering rule as regex or string.",
       "anyOf": [
         {
-          "instanceof": "RegExp"
+          "instanceof": "RegExp",
+          "tsType": "RegExp"
         },
         {
-          "type": "string"
+          "type": "string",
+          "minLength": 1
         }
       ]
-    }
-  },
-  "properties": {
-    "test": {
+    },
+    "Rules": {
+      "description": "Filtering rules.",
       "anyOf": [
         {
-          "$ref": "#/definitions/file-conditions"
-        },
-        {
+          "type": "array",
           "items": {
-            "anyOf": [
+            "description": "A rule condition.",
+            "oneOf": [
               {
-                "$ref": "#/definitions/file-conditions"
+                "$ref": "#/definitions/Rule"
               }
             ]
-          },
-          "type": "array"
+          }
+        },
+        {
+          "$ref": "#/definitions/Rule"
         }
       ]
-    },
-    "include": {
-      "anyOf": [
-        {
-          "$ref": "#/definitions/file-conditions"
-        },
+    }
+  },
+  "title": "TerserPluginOptions",
+  "type": "object",
+  "additionalProperties": false,
+  "properties": {
+    "test": {
+      "description": "Include all modules that pass test assertion.",
+      "oneOf": [
         {
-          "items": {
-            "anyOf": [
-              {
-                "$ref": "#/definitions/file-conditions"
-              }
-            ]
-          },
-          "type": "array"
+          "$ref": "#/definitions/Rules"
         }
       ]
     },
-    "exclude": {
-      "anyOf": [
-        {
-          "$ref": "#/definitions/file-conditions"
-        },
+    "include": {
+      "description": "Include all modules matching any of these conditions.",
+      "oneOf": [
         {
-          "items": {
-            "anyOf": [
-              {
-                "$ref": "#/definitions/file-conditions"
-              }
-            ]
-          },
-          "type": "array"
+          "$ref": "#/definitions/Rules"
         }
       ]
     },
-    "chunkFilter": {
-      "instanceof": "Function"
-    },
-    "cache": {
-      "anyOf": [
-        {
-          "type": "boolean"
-        },
+    "exclude": {
+      "description": "Exclude all modules matching any of these conditions.",
+      "oneOf": [
         {
-          "type": "string"
+          "$ref": "#/definitions/Rules"
         }
       ]
     },
-    "cacheKeys": {
-      "instanceof": "Function"
-    },
     "parallel": {
+      "description": "Use multi-process parallel running to improve the build speed.",
       "anyOf": [
         {
           "type": "boolean"
@@ -90,17 +72,17 @@
         }
       ]
     },
-    "sourceMap": {
-      "type": "boolean"
-    },
     "minify": {
+      "description": "Allows you to override default minify function.",
       "instanceof": "Function"
     },
     "terserOptions": {
+      "description": "Options for `terser`.",
       "additionalProperties": true,
       "type": "object"
     },
     "extractComments": {
+      "description": "Whether comments shall be extracted to a separate file.",
       "anyOf": [
         {
           "type": "boolean"
@@ -160,10 +142,6 @@
           "type": "object"
         }
       ]
-    },
-    "warningsFilter": {
-      "instanceof": "Function"
     }
-  },
-  "type": "object"
+  }
 }

test/__snapshots__/validate-options.test.js.snap

@@ -0,0 +1,178 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`validation 1`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.test should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.test should be an array:
+      [RegExp | non-empty string, ...]
+    * options.test should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.test should be an instance of RegExp.
+       * options.test should be a non-empty string."
+`;
+
+exports[`validation 2`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.test should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.test[0] should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.test[0] should be an instance of RegExp.
+       * options.test[0] should be a non-empty string."
+`;
+
+exports[`validation 3`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.include should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.include should be an array:
+      [RegExp | non-empty string, ...]
+    * options.include should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.include should be an instance of RegExp.
+       * options.include should be a non-empty string."
+`;
+
+exports[`validation 4`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.include should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.include[0] should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.include[0] should be an instance of RegExp.
+       * options.include[0] should be a non-empty string."
+`;
+
+exports[`validation 5`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.exclude should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.exclude should be an array:
+      [RegExp | non-empty string, ...]
+    * options.exclude should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.exclude should be an instance of RegExp.
+       * options.exclude should be a non-empty string."
+`;
+
+exports[`validation 6`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.exclude should be one of these:
+   [RegExp | non-empty string, ...] | RegExp | non-empty string
+   -> Filtering rules.
+   Details:
+    * options.exclude[0] should be one of these:
+      RegExp | non-empty string
+      -> Filtering rule as regex or string.
+      Details:
+       * options.exclude[0] should be an instance of RegExp.
+       * options.exclude[0] should be a non-empty string."
+`;
+
+exports[`validation 7`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.parallel should be one of these:
+   boolean | integer
+   -> Use multi-process parallel running to improve the build speed.
+   Details:
+    * options.parallel should be a boolean.
+    * options.parallel should be a integer."
+`;
+
+exports[`validation 8`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.parallel should be one of these:
+   boolean | integer
+   -> Use multi-process parallel running to improve the build speed.
+   Details:
+    * options.parallel should be a boolean.
+    * options.parallel should be a integer."
+`;
+
+exports[`validation 9`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.minify should be an instance of function.
+   -> Allows you to override default minify function."
+`;
+
+exports[`validation 10`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.terserOptions should be an object:
+   object { … }
+   -> Options for \`terser\`."
+`;
+
+exports[`validation 11`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.extractComments should be one of these:
+   boolean | string | RegExp | function | object { condition?, filename?, banner? }
+   -> Whether comments shall be extracted to a separate file.
+   Details:
+    * options.extractComments.condition should be one of these:
+      boolean | string | RegExp | function
+      Details:
+       * options.extractComments.condition should be a boolean.
+       * options.extractComments.condition should be a string.
+       * options.extractComments.condition should be an instance of RegExp.
+       * options.extractComments.condition should be an instance of function."
+`;
+
+exports[`validation 12`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.extractComments should be one of these:
+   boolean | string | RegExp | function | object { condition?, filename?, banner? }
+   -> Whether comments shall be extracted to a separate file.
+   Details:
+    * options.extractComments.filename should be one of these:
+      string | function
+      Details:
+       * options.extractComments.filename should be a string.
+       * options.extractComments.filename should be an instance of function."
+`;
+
+exports[`validation 13`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.extractComments should be one of these:
+   boolean | string | RegExp | function | object { condition?, filename?, banner? }
+   -> Whether comments shall be extracted to a separate file.
+   Details:
+    * options.extractComments.banner should be one of these:
+      boolean | string | function
+      Details:
+       * options.extractComments.banner should be a boolean.
+       * options.extractComments.banner should be a string.
+       * options.extractComments.banner should be an instance of function."
+`;
+
+exports[`validation 14`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options.extractComments has an unknown property 'unknown'. These properties are valid:
+   object { condition?, filename?, banner? }"
+`;
+
+exports[`validation 15`] = `
+"Invalid options object. Terser Plugin has been initialized using an options object that does not match the API schema.
+ - options has an unknown property 'unknown'. These properties are valid:
+   object { test?, include?, exclude?, parallel?, minify?, terserOptions?, extractComments? }"
+`;

test/__snapshots__/worker.test.js.snap

@@ -1,61 +1,177 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`matches snapshot normalizes when options.extractComments is regex: test1.js 1`] = `
+exports[`worker normalizes when minimizerOptions.output.comments is string: all 1`] = `
+Object {
+  "code": "var foo=1;/* hello */
+// Comment
+/* duplicate */
+/* duplicate */",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when minimizerOptions.compress.comments is boolean 1`] = `
 Object {
   "code": "var foo=1;",
-  "error": undefined,
   "extractedComments": Array [],
-  "map": undefined,
-  "warnings": undefined,
 }
 `;
 
-exports[`matches snapshot normalizes when terserOptions.extractComments is number: test4.js 1`] = `
+exports[`worker should match snapshot when minimizerOptions.compress.comments is object 1`] = `
 Object {
   "code": "var foo=1;",
-  "error": undefined,
   "extractedComments": Array [],
-  "map": undefined,
-  "warnings": undefined,
 }
 `;
 
-exports[`matches snapshot normalizes when terserOptions.output.comments is string: all: test2.js 1`] = `
+exports[`worker should match snapshot when minimizerOptions.extractComments is number 1`] = `
 Object {
-  "code": "var foo=1;/* hello */",
-  "error": undefined,
+  "code": "var foo=1;",
   "extractedComments": Array [],
-  "map": undefined,
-  "warnings": undefined,
 }
 `;
 
-exports[`matches snapshot normalizes when terserOptions.output.comments is string: some: test3.js 1`] = `
+exports[`worker should match snapshot when minimizerOptions.mangle is "null" 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when minimizerOptions.mangle is boolean 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when minimizerOptions.mangle is object 1`] = `
+Object {
+  "code": "var a=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when minimizerOptions.output.comments is string: some 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is "all" value 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [
+    "/* hello */",
+    "// Comment",
+    "/* duplicate */",
+  ],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is "false" 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is "some" value 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is "true" 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is "true" 2`] = `
+"var foo = 1;/* hello */
+// Comment
+/* duplicate */
+/* duplicate */"
+`;
+
+exports[`worker should match snapshot when options.extractComments is Function 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [
+    "/* hello */",
+    "// Comment",
+    "/* duplicate */",
+  ],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is Object with "all" value 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [
+    "/* hello */",
+    "// Comment",
+    "/* duplicate */",
+  ],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is Object with "some" value 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is Object with "true" value 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is RegExp 1`] = `
+Object {
+  "code": "var foo=1;",
+  "extractedComments": Array [
+    "/* hello */",
+  ],
+}
+`;
+
+exports[`worker should match snapshot when options.extractComments is empty Object 1`] = `
 Object {
   "code": "var foo=1;",
-  "error": undefined,
   "extractedComments": Array [],
-  "map": undefined,
-  "warnings": undefined,
 }
 `;
 
-exports[`matches snapshot when applied with extract option set to a single file: test5.js 1`] = `
+exports[`worker should match snapshot with extract option set to a single file 1`] = `
 Object {
   "code": "/******/function hello(o){console.log(o)}",
-  "error": undefined,
   "extractedComments": Array [],
-  "map": undefined,
-  "warnings": undefined,
 }
 `;
 
-exports[`matches snapshot when options.inputSourceMap: test6.js 1`] = `
+exports[`worker should match snapshot with options.inputSourceMap 1`] = `
 Object {
   "code": "function foo(f){if(f)return bar()}",
-  "error": undefined,
   "extractedComments": Array [],
-  "map": "{\\"version\\":3,\\"sources\\":[\\"test1.js\\"],\\"names\\":[\\"foo\\",\\"x\\",\\"not_called1\\"],\\"mappings\\":\\"AAAA,SAASA,IAAIC,GACT,GACIA,EAAA,OACAC\\"}",
-  "warnings": undefined,
+  "map": Object {
+    "mappings": "AAAA,SAASA,IAAIC,GAAK,GAAIA,EAAK,OAAOC",
+    "names": Array [
+      "foo",
+      "x",
+      "bar",
+    ],
+    "sources": Array [
+      "test6.js",
+    ],
+    "version": 3,
+  },
 }
 `;

test/cjs.test.js

@@ -1,8 +1,8 @@
-import TerserPlugin from '../src';
-import CJSTerserPlugin from '../src/cjs';
+import src from '../src';
+import cjs from '../src/cjs';
 
 describe('CJS', () => {
-  it('should exported plugin', () => {
-    expect(CJSTerserPlugin).toEqual(TerserPlugin);
+  it('should export loader', () => {
+    expect(cjs).toEqual(src);
   });
 });

test/exclude-option.test.js

@@ -1,105 +1,73 @@
+import path from 'path';
+
 import TerserPlugin from '../src/index';
 
-import { cleanErrorStack, createCompiler, compile } from './helpers';
+import {
+  compile,
+  getCompiler,
+  getErrors,
+  getWarnings,
+  readsAssets,
+} from './helpers';
 
-describe('when applied with `exclude` option', () => {
+describe('exclude option', () => {
   let compiler;
 
   beforeEach(() => {
-    compiler = createCompiler({
+    compiler = getCompiler({
       entry: {
-        excluded1: `${__dirname}/fixtures/excluded1.js`,
-        excluded2: `${__dirname}/fixtures/excluded2.js`,
-        entry: `${__dirname}/fixtures/entry.js`,
+        excluded1: path.resolve(__dirname, './fixtures/excluded1.js'),
+        excluded2: path.resolve(__dirname, './fixtures/excluded2.js'),
+        entry: path.resolve(__dirname, './fixtures/entry.js'),
       },
     });
   });
 
-  it('matches snapshot for a single `exclude` value ({RegExp})', () => {
+  it('should match snapshot for a single RegExp value', async () => {
     new TerserPlugin({
       exclude: /excluded1/i,
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
-
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
+    const stats = await compile(compiler);
 
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for a single `exclude` value ({String})', () => {
+  it('should match snapshot for a single String value', async () => {
     new TerserPlugin({
       exclude: 'excluded1',
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for multiple `exclude` values ({RegExp})', () => {
+  it('should match snapshot for multiple RegExp values', async () => {
     new TerserPlugin({
       exclude: [/excluded1/i, /excluded2/i],
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for multiple `exclude` values ({String})', () => {
+  it('should match snapshot for multiple String values', async () => {
     new TerserPlugin({
       exclude: ['excluded1', 'excluded2'],
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 });

test/fixtures/asset-resource.js

@@ -0,0 +1,7 @@
+import script from './emitted.js'
+
+const myVar = 12;
+
+console.log(myVar, script);
+
+export default 12;

test/fixtures/comments.js

@@ -26,4 +26,6 @@ import('./nested/comments.js');
 * Foo
 */
 
+// @lic
+
 module.exports = Math.random();

test/fixtures/copy.cjs

@@ -0,0 +1,2 @@
+var foo = 12;
+console.log(foo);

test/fixtures/copy.js

@@ -0,0 +1,2 @@
+var foo = 12;
+console.log(foo);

test/fixtures/copy.mjs

@@ -0,0 +1,2 @@
+var foo = 12;
+console.log(foo);

test/fixtures/emit-loader.js

@@ -0,0 +1,5 @@
+module.exports = function(content) {
+  this.emitFile("extra-file.js", 'var a = 1; console.log(a);');
+
+  return content;
+};

test/fixtures/emitted.js

@@ -0,0 +1 @@
+console.log('HERE');

test/fixtures/entry.mjs

@@ -1,9 +1,12 @@
 // foo
-/* @preserve*/
 // bar
 const a = 2 + 2;
 
-module.exports = function Foo() {
+function test() {
   const b = 2 + 2;
-  console.log(b + 1 + 2);
-};
+  console.log(b + 1 + 2 + a);
+}
+
+test();
+
+module.exports = test;

test/fixtures/file-loader.js

@@ -0,0 +1,7 @@
+import script from '!!file-loader?name=[path][name].[ext]!./emitted.js'
+
+const myVar = 12;
+
+console.log(myVar, script);
+
+export default 12;

test/fixtures/file.js

@@ -0,0 +1 @@
+module.exports = "ok";

test/fixtures/file.worker.js

@@ -0,0 +1,7 @@
+/*! Legal Comment 1 */
+
+/*! Legal Comment 2 */
+
+/*! Legal Comment 3 */
+
+onmessage = function (event) {};

test/fixtures/shebang-1.js

@@ -0,0 +1 @@
+console.log('HERE');

test/fixtures/shebang.js

@@ -0,0 +1,3 @@
+/* Comment */
+/*! Legal Comment */
+console.log('HERE');

test/fixtures/worker-loader.js

@@ -0,0 +1,10 @@
+/*! Legal Comment */
+
+import Worker from './file.worker.js';
+
+const worker = new Worker();
+
+worker.postMessage({ a: 1 });
+worker.onmessage = function (event) {};
+
+worker.addEventListener('message', function (event) {});

test/helpers/BrokenCodePlugin.js

@@ -0,0 +1,16 @@
+import webpack from 'webpack';
+
+export default class BrokenCodePlugin {
+  apply(compiler) {
+    const plugin = { name: this.constructor.name };
+
+    compiler.hooks.thisCompilation.tap(plugin, (compilation) => {
+      compilation.hooks.additionalAssets.tap(plugin, () => {
+        // eslint-disable-next-line no-param-reassign
+        compilation.assets['broken.js'] = new webpack.sources.RawSource(
+          '`Broken==='
+        );
+      });
+    });
+  }
+}

test/helpers/ExistingCommentsFile.js

@@ -0,0 +1,16 @@
+import webpack from 'webpack';
+
+export default class ExistingCommentsFile {
+  apply(compiler) {
+    const plugin = { name: this.constructor.name };
+
+    compiler.hooks.thisCompilation.tap(plugin, (compilation) => {
+      compilation.hooks.additionalAssets.tap(plugin, () => {
+        // eslint-disable-next-line no-param-reassign
+        compilation.assets['licenses.txt'] = new webpack.sources.RawSource(
+          '// Existing Comment'
+        );
+      });
+    });
+  }
+}

test/helpers/ModifyExistingAsset.js

@@ -0,0 +1,25 @@
+import webpack from 'webpack';
+
+export default class ExistingCommentsFile {
+  constructor(options = {}) {
+    this.options = options;
+  }
+
+  apply(compiler) {
+    const plugin = { name: this.constructor.name };
+
+    compiler.hooks.thisCompilation.tap(plugin, (compilation) => {
+      compilation.hooks.additionalAssets.tap(plugin, () => {
+        // eslint-disable-next-line no-param-reassign
+        compilation.assets[
+          this.options.name
+        ] = new webpack.sources.ConcatSource(
+          `function changed() {} ${
+            this.options.comment ? '/*! CHANGED */' : ''
+          }`,
+          compilation.assets[this.options.name]
+        );
+      });
+    });
+  }
+}

test/helpers/compile.js

@@ -0,0 +1,11 @@
+export default (compiler) => {
+  return new Promise((resolve, reject) => {
+    compiler.run((error, stats) => {
+      if (error) {
+        return reject(error);
+      }
+
+      return resolve(stats);
+    });
+  });
+};

test/helpers/countPlugins.js

@@ -0,0 +1,9 @@
+export default function countPlugins({ hooks }) {
+  return Object.keys(hooks).reduce((aggregate, name) => {
+    // eslint-disable-next-line no-param-reassign
+    aggregate[name] = Array.isArray(hooks[name].taps)
+      ? hooks[name].taps.length
+      : 0;
+    return aggregate;
+  }, {});
+}

test/helpers/execute.js

@@ -0,0 +1,22 @@
+import Module from 'module';
+import path from 'path';
+
+const parentModule = module;
+
+export default (code) => {
+  const resource = 'test.js';
+  const module = new Module(resource, parentModule);
+  // eslint-disable-next-line no-underscore-dangle
+  module.paths = Module._nodeModulePaths(
+    path.resolve(__dirname, '../fixtures')
+  );
+  module.filename = resource;
+
+  // eslint-disable-next-line no-underscore-dangle
+  module._compile(
+    `let __export__;${code};module.exports = __export__;`,
+    resource
+  );
+
+  return module.exports;
+};

test/helpers/getCompiler.js

@@ -0,0 +1,31 @@
+import path from 'path';
+
+import webpack from 'webpack';
+import { createFsFromVolume, Volume } from 'memfs';
+
+export default function getCompiler(options = {}) {
+  const compiler = webpack(
+    Array.isArray(options)
+      ? options
+      : {
+          mode: 'production',
+          bail: true,
+          entry: path.resolve(__dirname, '../fixtures/entry.js'),
+          optimization: {
+            minimize: false,
+          },
+          output: {
+            pathinfo: false,
+            path: path.resolve(__dirname, 'dist'),
+            filename: '[name].js',
+            chunkFilename: '[id].[name].js',
+          },
+          plugins: [],
+          ...options,
+        }
+  );
+
+  compiler.outputFileSystem = createFsFromVolume(new Volume());
+
+  return compiler;
+}

test/helpers/getErrors.js

@@ -0,0 +1,5 @@
+import normalizeErrors from './normalizeErrors';
+
+export default (stats) => {
+  return normalizeErrors(stats.compilation.errors).sort();
+};

test/helpers/getWarnings.js

@@ -0,0 +1,5 @@
+import normalizeErrors from './normalizeErrors';
+
+export default (stats) => {
+  return normalizeErrors(stats.compilation.warnings).sort();
+};

test/helpers/index.js

@@ -0,0 +1,27 @@
+import BrokenCodePlugin from './BrokenCodePlugin';
+import compile from './compile';
+import countPlugins from './countPlugins';
+import execute from './execute';
+import ExistingCommentsFile from './ExistingCommentsFile';
+import getCompiler from './getCompiler';
+import getErrors from './getErrors';
+import getWarnings from './getWarnings';
+import ModifyExistingAsset from './ModifyExistingAsset';
+import readAsset from './readAsset';
+import readsAssets from './readAssets';
+import normalizeErrors from './normalizeErrors';
+
+export {
+  BrokenCodePlugin,
+  compile,
+  countPlugins,
+  ExistingCommentsFile,
+  execute,
+  getCompiler,
+  getErrors,
+  getWarnings,
+  ModifyExistingAsset,
+  normalizeErrors,
+  readAsset,
+  readsAssets,
+};

test/helpers/normalizeErrors.js

@@ -0,0 +1,19 @@
+function removeCWD(str) {
+  const isWin = process.platform === 'win32';
+  let cwd = process.cwd();
+
+  if (isWin) {
+    // eslint-disable-next-line no-param-reassign
+    str = str.replace(/\\/g, '/');
+    // eslint-disable-next-line no-param-reassign
+    cwd = cwd.replace(/\\/g, '/');
+  }
+
+  return str.replace(new RegExp(cwd, 'g'), '');
+}
+
+export default (errors) => {
+  return errors.map((error) =>
+    removeCWD(error.toString().split('\n').slice(0, 2).join('\n'))
+  );
+};

test/helpers/readAsset.js

@@ -0,0 +1,23 @@
+import path from 'path';
+
+export default (asset, compiler, stats) => {
+  const usedFs = compiler.outputFileSystem;
+  const outputPath = stats.compilation.outputOptions.path;
+
+  let data = '';
+  let targetFile = asset;
+
+  const queryStringIdx = targetFile.indexOf('?');
+
+  if (queryStringIdx >= 0) {
+    targetFile = targetFile.substr(0, queryStringIdx);
+  }
+
+  try {
+    data = usedFs.readFileSync(path.join(outputPath, targetFile)).toString();
+  } catch (error) {
+    data = error.toString();
+  }
+
+  return data;
+};

test/helpers/readAssets.js

@@ -0,0 +1,11 @@
+import readAsset from './readAsset';
+
+export default function readAssets(compiler, stats) {
+  const assets = {};
+
+  Object.keys(stats.compilation.assets).forEach((asset) => {
+    assets[asset] = readAsset(asset, compiler, stats);
+  });
+
+  return assets;
+}

test/helpers/snapshotResolver.js

@@ -0,0 +1,28 @@
+const path = require('path');
+
+const webpack = require('webpack');
+
+// eslint-disable-next-line global-require
+const [webpackVersion] = webpack.version;
+const snapshotExtension = `.snap.webpack${webpackVersion}`;
+
+// eslint-disable-next-line no-console
+console.log('Current webpack version:', webpackVersion);
+
+module.exports = {
+  resolveSnapshotPath: (testPath) =>
+    path.join(
+      path.dirname(testPath),
+      '__snapshots__',
+      `${path.basename(testPath)}${snapshotExtension}`
+    ),
+  resolveTestPath: (snapshotPath) =>
+    snapshotPath
+      .replace(`${path.sep}__snapshots__`, '')
+      .slice(0, -snapshotExtension.length),
+  testPathForConsistencyCheck: path.join(
+    'consistency_check',
+    '__tests__',
+    'example.test.js'
+  ),
+};

test/include-option.test.js

@@ -1,105 +1,73 @@
+import path from 'path';
+
 import TerserPlugin from '../src/index';
 
-import { cleanErrorStack, createCompiler, compile } from './helpers';
+import {
+  compile,
+  getCompiler,
+  getErrors,
+  getWarnings,
+  readsAssets,
+} from './helpers';
 
-describe('when applied with `include` option', () => {
+describe('include option', () => {
   let compiler;
 
   beforeEach(() => {
-    compiler = createCompiler({
+    compiler = getCompiler({
       entry: {
-        included1: `${__dirname}/fixtures/included1.js`,
-        included2: `${__dirname}/fixtures/included2.js`,
-        entry: `${__dirname}/fixtures/entry.js`,
+        included1: path.resolve(__dirname, './fixtures/included1.js'),
+        included2: path.resolve(__dirname, './fixtures/included2.js'),
+        entry: path.resolve(__dirname, './fixtures/entry.js'),
       },
     });
   });
 
-  it('matches snapshot for a single `include` value ({RegExp})', () => {
+  it('should match snapshot for a single RegExp value', async () => {
     new TerserPlugin({
       include: /included1/i,
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
-
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
+    const stats = await compile(compiler);
 
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for a single `include` value ({String})', () => {
+  it('should match snapshot for a single String value', async () => {
     new TerserPlugin({
       include: 'included1',
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for multiple `include` values  ({RegExp})', () => {
+  it('should match snapshot for multiple RegExp values', async () => {
     new TerserPlugin({
       include: [/included1/i, /included2/i],
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 
-  it('matches snapshot for multiple `include` values  ({String})', () => {
+  it('should match snapshot for multiple String values', async () => {
     new TerserPlugin({
       include: ['included1', 'included2'],
     }).apply(compiler);
 
-    return compile(compiler).then((stats) => {
-      const errors = stats.compilation.errors.map(cleanErrorStack);
-      const warnings = stats.compilation.warnings.map(cleanErrorStack);
+    const stats = await compile(compiler);
 
-      expect(errors).toMatchSnapshot('errors');
-      expect(warnings).toMatchSnapshot('warnings');
-
-      for (const file in stats.compilation.assets) {
-        if (
-          Object.prototype.hasOwnProperty.call(stats.compilation.assets, file)
-        ) {
-          expect(stats.compilation.assets[file].source()).toMatchSnapshot(file);
-        }
-      }
-    });
+    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
   });
 });