feat(mixin): split a class in independant parts (#3415)

@xen-orchestra/mixin/.babelrc.js

@@ -0,0 +1,3 @@
+module.exports = require('../../@xen-orchestra/babel-config')(
+  require('./package.json')
+)

@xen-orchestra/mixin/.npmignore

@@ -0,0 +1,24 @@
+/benchmark/
+/benchmarks/
+*.bench.js
+*.bench.js.map
+
+/examples/
+example.js
+example.js.map
+*.example.js
+*.example.js.map
+
+/fixture/
+/fixtures/
+*.fixture.js
+*.fixture.js.map
+*.fixtures.js
+*.fixtures.js.map
+
+/test/
+/tests/
+*.spec.js
+*.spec.js.map
+
+__snapshots__/

@xen-orchestra/mixin/README.md

@@ -0,0 +1,49 @@
+# ${pkg.name} [![Build Status](https://travis-ci.org/${pkg.shortGitHubPath}.png?branch=master)](https://travis-ci.org/${pkg.shortGitHubPath})
+
+> ${pkg.description}
+
+## Install
+
+Installation of the [npm package](https://npmjs.org/package/${pkg.name}):
+
+```
+> npm install --save ${pkg.name}
+```
+
+## Usage
+
+**TODO**
+
+## Development
+
+```
+# Install dependencies
+> yarn
+
+# Run the tests
+> yarn test
+
+# Continuously compile
+> yarn dev
+
+# Continuously run the tests
+> yarn dev-test
+
+# Build for production (automatically called by npm install)
+> yarn build
+```
+
+## Contributions
+
+Contributions are *very* welcomed, either on the documentation or on
+the code.
+
+You may:
+
+- report any [issue](${pkg.bugs})
+  you've encountered;
+- fork and create a pull request.
+
+## License
+
+${pkg.license} © [${pkg.author.name}](${pkg.author.url})

@xen-orchestra/mixin/package.json

@@ -0,0 +1,49 @@
+{
+  "name": "@xen-orchestra/mixin",
+  "version": "0.0.0",
+  "license": "ISC",
+  "description": "",
+  "keywords": [],
+  "homepage": "https://github.com/vatesfr/xen-orchestra/tree/master/@xen-orchestra/mixin",
+  "bugs": "https://github.com/vatesfr/xen-orchestra/issues",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/vatesfr/xen-orchestra.git"
+  },
+  "author": {
+    "name": "Julien Fontanet",
+    "email": "julien.fontanet@vates.fr"
+  },
+  "preferGlobal": false,
+  "main": "dist/",
+  "bin": {},
+  "files": [
+    "dist/"
+  ],
+  "browserslist": [
+    ">2%"
+  ],
+  "engines": {
+    "node": ">=6"
+  },
+  "dependencies": {
+    "bind-property-descriptor": "^1.0.0"
+  },
+  "devDependencies": {
+    "@babel/cli": "7.0.0",
+    "@babel/core": "7.0.0",
+    "@babel/preset-env": "7.0.0",
+    "babel-plugin-dev": "^1.0.0",
+    "babel-plugin-lodash": "^3.3.2",
+    "cross-env": "^5.1.3",
+    "rimraf": "^2.6.2"
+  },
+  "scripts": {
+    "build": "cross-env NODE_ENV=production babel --source-maps --out-dir=dist/ src/",
+    "clean": "rimraf dist/",
+    "dev": "cross-env NODE_ENV=development babel --watch --source-maps --out-dir=dist/ src/",
+    "prebuild": "yarn run clean",
+    "predev": "yarn run prebuild",
+    "prepublishOnly": "yarn run build"
+  }
+}

@xen-orchestra/mixin/src/index.js

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+import { getBoundPropertyDescriptor } from 'bind-property-descriptor'
+
+// ===================================================================
+
+const { defineProperties, getOwnPropertyDescriptor } = Object
+
+const isIgnoredProperty = name => name[0] === '_' || name === 'constructor'
+
+const IGNORED_STATIC_PROPERTIES = {
+  __proto__: null,
+
+  arguments: true,
+  caller: true,
+  length: true,
+  name: true,
+  prototype: true,
+}
+const isIgnoredStaticProperty = name => name in IGNORED_STATIC_PROPERTIES
+
+const ownKeys =
+  (typeof Reflect !== 'undefined' && Reflect.ownKeys) ||
+  (({ getOwnPropertyNames: names, getOwnPropertySymbols: symbols }) =>
+    symbols !== undefined ? obj => names(obj).concat(symbols(obj)) : names)(
+    Object
+  )
+
+// -------------------------------------------------------------------
+
+const mixin = Mixins => Class => {
+  if (__DEV__ && !Array.isArray(Mixins)) {
+    throw new TypeError('Mixins should be an array')
+  }
+
+  const { name } = Class
+
+  // Copy properties of plain object mix-ins to the prototype.
+  {
+    const allMixins = Mixins
+    Mixins = []
+    const { prototype } = Class
+    const descriptors = { __proto__: null }
+    allMixins.forEach(Mixin => {
+      if (typeof Mixin === 'function') {
+        Mixins.push(Mixin)
+        return
+      }
+
+      for (const prop of ownKeys(Mixin)) {
+        if (__DEV__ && prop in prototype) {
+          throw new Error(`${name}#${prop} is already defined`)
+        }
+
+        ;(descriptors[prop] = getOwnPropertyDescriptor(
+          Mixin,
+          prop
+        )).enumerable = false // Object methods are enumerable but class methods are not.
+      }
+    })
+    defineProperties(prototype, descriptors)
+  }
+
+  const n = Mixins.length
+
+  function DecoratedClass (...args) {
+    const instance = new Class(...args)
+
+    for (let i = 0; i < n; ++i) {
+      const Mixin = Mixins[i]
+      const { prototype } = Mixin
+      const mixinInstance = new Mixin(instance, ...args)
+      const descriptors = { __proto__: null }
+      const props = ownKeys(prototype)
+      for (let j = 0, m = props.length; j < m; ++j) {
+        const prop = props[j]
+
+        if (isIgnoredProperty(prop)) {
+          continue
+        }
+
+        if (prop in instance) {
+          throw new Error(`${name}#${prop} is already defined`)
+        }
+
+        descriptors[prop] = getBoundPropertyDescriptor(
+          prototype,
+          prop,
+          mixinInstance
+        )
+      }
+      defineProperties(instance, descriptors)
+    }
+
+    return instance
+  }
+
+  // Copy original and mixed-in static properties on Decorator class.
+  const descriptors = { __proto__: null }
+  ownKeys(Class).forEach(prop => {
+    let descriptor
+    if (
+      !(
+        isIgnoredStaticProperty(prop) &&
+        // if they already exist...
+        (descriptor = getOwnPropertyDescriptor(DecoratedClass, prop)) !==
+          undefined &&
+        // and are not configurable.
+        !descriptor.configurable
+      )
+    ) {
+      descriptors[prop] = getOwnPropertyDescriptor(Class, prop)
+    }
+  })
+  Mixins.forEach(Mixin => {
+    ownKeys(Mixin).forEach(prop => {
+      if (isIgnoredStaticProperty(prop)) {
+        return
+      }
+
+      if (__DEV__ && prop in descriptors) {
+        throw new Error(`${name}.${prop} is already defined`)
+      }
+
+      descriptors[prop] = getOwnPropertyDescriptor(Mixin, prop)
+    })
+  })
+  defineProperties(DecoratedClass, descriptors)
+
+  return DecoratedClass
+}
+export { mixin as default }