Remove @babel/preset-env, drop support for Node 8 and below

Author: cpojer

.travis.yml

@@ -1,7 +1,6 @@
 sudo: false
 language: node_js
 node_js:
-  - 6
-  - 8
   - 10
+  - 12
   - stable

package.json

@@ -26,8 +26,9 @@
     "@babel/core": "^7.1.6",
     "@babel/parser": "^7.1.6",
     "@babel/plugin-proposal-class-properties": "^7.1.0",
-    "@babel/plugin-proposal-object-rest-spread": "^7.0.0",
-    "@babel/preset-env": "^7.1.6",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.1.0",
+    "@babel/plugin-proposal-optional-chaining": "^7.1.0",
+    "@babel/plugin-transform-modules-commonjs": "^7.1.0",
     "@babel/preset-flow": "^7.0.0",
     "@babel/preset-typescript": "^7.1.0",
     "@babel/register": "^7.0.0",
@@ -42,6 +43,9 @@
     "temp": "^0.8.1",
     "write-file-atomic": "^2.3.0"
   },
+  "optionalDependencies": {
+    "@babel/preset-env": "^7.1.6"
+  },
   "devDependencies": {
     "babel-eslint": "^10.0.1",
     "eslint": "^5.9.0",

src/Worker.js

@@ -18,6 +18,11 @@ const getParser = require('./getParser');
 
 const jscodeshift = require('./core');
 
+let presetEnv;
+try {
+  presetEnv = require('@babel/preset-env');
+} catch {}
+
 let emitter;
 let finish;
 let notify;
@@ -48,19 +53,27 @@ function prepareJscodeshift(options) {
 
 function setup(tr, babel) {
   if (babel === 'babel') {
+    const presets = [];
+    if (presetEnv) {
+      presets.push([
+        presetEnv.default,
+        {targets: {node: true}},
+      ]);
+    }
+    presets.push(
+      /\.tsx?$/.test(tr) ?
+        require('@babel/preset-typescript').default :
+        require('@babel/preset-flow').default
+    );
+
     require('@babel/register')({
       babelrc: false,
-      presets: [
-        [
-          require('@babel/preset-env').default,
-          {targets: {node: true}},
-        ],
-        /\.tsx?$/.test(tr) ?
-          require('@babel/preset-typescript').default :
-          require('@babel/preset-flow').default,
-      ],
+      presets,
       plugins: [
         require('@babel/plugin-proposal-class-properties').default,
+        require('@babel/plugin-proposal-nullish-coalescing-operator').default,
+        require('@babel/plugin-proposal-optional-chaining').default,
+        require('@babel/plugin-transform-modules-commonjs').default,
       ],
       extensions: [...DEFAULT_EXTENSIONS, '.ts', '.tsx'],
       // By default, babel register only compiles things inside the current working directory.