Upgrade to Babel 7 stable (#5042) (major)

🎉 https://twitter.com/left_pad/status/1034204330352500736

package.json

@@ -42,6 +42,11 @@
     "prepublish": "npm run release",
     "precommit": "lint-staged"
   },
+  "taskr": {
+    "requires": [
+      "./taskfile-babel.js"
+    ]
+  },
   "standard": {
     "parser": "babel-eslint",
     "ignore": [
@@ -57,17 +62,17 @@
     "bin/*": "standard"
   },
   "dependencies": {
-    "@babel/core": "7.0.0-rc.1",
-    "@babel/plugin-proposal-class-properties": "7.0.0-rc.1",
-    "@babel/plugin-proposal-object-rest-spread": "7.0.0-rc.1",
-    "@babel/plugin-syntax-dynamic-import": "7.0.0-rc.1",
-    "@babel/plugin-transform-react-jsx-source": "7.0.0-rc.1",
-    "@babel/plugin-transform-runtime": "7.0.0-rc.1",
-    "@babel/preset-env": "7.0.0-rc.1",
-    "@babel/preset-react": "7.0.0-rc.1",
-    "@babel/runtime": "7.0.0-rc.1",
-    "@babel/runtime-corejs2": "7.0.0-rc.1",
-    "@babel/template": "7.0.0-rc.1",
+    "@babel/core": "7.0.0",
+    "@babel/plugin-proposal-class-properties": "7.0.0",
+    "@babel/plugin-proposal-object-rest-spread": "7.0.0",
+    "@babel/plugin-syntax-dynamic-import": "7.0.0",
+    "@babel/plugin-transform-react-jsx-source": "7.0.0",
+    "@babel/plugin-transform-runtime": "7.0.0",
+    "@babel/preset-env": "7.0.0",
+    "@babel/preset-react": "7.0.0",
+    "@babel/runtime": "7.0.0",
+    "@babel/runtime-corejs2": "7.0.0",
+    "@babel/template": "7.0.0",
     "ansi-html": "0.0.7",
     "autodll-webpack-plugin": "0.4.2",
     "babel-core": "7.0.0-bridge.0",
@@ -113,16 +118,15 @@
     "write-file-webpack-plugin": "4.3.2"
   },
   "devDependencies": {
-    "@babel/preset-flow": "7.0.0-rc.1",
-    "@taskr/babel": "1.1.0-next.1",
+    "@babel/preset-flow": "7.0.0",
     "@taskr/clear": "1.1.0",
     "@taskr/esnext": "1.1.0",
     "@taskr/watch": "1.1.0",
     "@zeit/next-css": "0.2.1-canary.1",
     "@zeit/next-sass": "0.2.1-canary.1",
     "@zeit/next-typescript": "1.1.0",
-    "babel-eslint": "8.2.2",
-    "babel-jest": "21.2.0",
+    "babel-eslint": "9.0.0",
+    "babel-jest": "23.4.2",
     "benchmark": "2.1.4",
     "cheerio": "0.22.0",
     "chromedriver": "2.32.3",
@@ -131,6 +135,7 @@
     "cross-env": "5.0.5",
     "express": "4.15.5",
     "fkill": "5.1.0",
+    "flatten": "1.0.2",
     "flow-bin": "0.73.0",
     "get-port": "3.2.0",
     "husky": "0.14.3",

taskfile-babel.js

@@ -0,0 +1,65 @@
+// taskr babel plugin with Babel 7 support
+// https://github.com/lukeed/taskr/pull/305
+'use strict'
+
+const transform = require('@babel/core').transform
+const flatten = require('flatten')
+
+const BABEL_REGEX = /(^@babel\/)(preset|plugin)-(.*)/i
+
+function getBabels () {
+  const pkg = require('./package.json')
+  return flatten(
+    ['devDependencies', 'dependencies'].map(s => Object.keys(pkg[s] || {}))
+  ).filter(s => BABEL_REGEX.test(s))
+}
+
+module.exports = function (task) {
+  let cache
+
+  task.plugin('babel', {}, function * (file, opts) {
+    if (opts.preload) {
+      delete opts.preload
+      // get dependencies
+      cache = cache || getBabels()
+
+      // attach any deps to babel's `opts`
+      cache.forEach(dep => {
+        const segs = BABEL_REGEX.exec(dep)
+        const type = `${segs[2]}s`
+        const name = `@babel/${segs[2]}-${segs[3]}`
+
+        opts[type] = opts[type] || []
+
+        // flatten all (advanced entries are arrays)
+        if (flatten(opts[type]).indexOf(name) === -1) {
+          opts[type] = opts[type].concat(name)
+        }
+      })
+    }
+
+    // attach file's name
+    opts.filename = file.base
+
+    const output = transform(file.data, opts)
+
+    if (output.map) {
+      const map = `${file.base}.map`
+
+      // append `sourceMappingURL` to original file
+      if (opts.sourceMaps !== 'both') {
+        output.code += Buffer.from(`\n//# sourceMappingURL=${map}`)
+      }
+
+      // add sourcemap to `files` array
+      this._.files.push({
+        base: map,
+        dir: file.dir,
+        data: Buffer.from(JSON.stringify(output.map))
+      })
+    }
+
+    // update file's data
+    file.data = Buffer.from(output.code)
+  })
+}