feat(emit-async): handle async listeners (#3416)

Extracted from xo-server.

@xen-orchestra/emit-async/.babelrc.js

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

@xen-orchestra/emit-async/.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/emit-async/README.md

@@ -0,0 +1,71 @@
+# @xen-orchestra/emit-async [![Build Status](https://travis-ci.org/${pkg.shortGitHubPath}.png?branch=master)](https://travis-ci.org/${pkg.shortGitHubPath})
+
+> ${pkg.description}
+
+## Install
+
+Installation of the [npm package](https://npmjs.org/package/@xen-orchestra/emit-async):
+
+```
+> npm install --save @xen-orchestra/emit-async
+```
+
+## Usage
+
+```js
+import EE from 'events'
+import emitAsync from '@xen-orchestra/emit-async'
+
+const ee = new EE()
+ee.emitAsync = emitAsync
+
+ee.on('start', async function () {
+  // whatever
+})
+
+// similar to EventEmmiter#emit() but returns a promise which resolves when all
+// listeners have resolved
+await ee.emitAsync('start')
+
+// by default, it will rejects as soon as one listener reject, you can customise
+// error handling though:
+await ee.emitAsync({
+  onError (error) {
+    console.warn(error)
+  }
+}, 'start')
+```
+
+## Development
+
+```
+# Install dependencies
+> yarn
+
+# Run the tests
+> yarn test
+
+# Continuously compile
+> yarn dev
+
+# Continuously run the tests
+> yarn dev-test
+
+# Build for production (automatically called by npm install)
+> yarn build
+```
+
+## Contributions
+
+Contributions are *very* welcomed, either on the documentation or on
+the code.
+
+You may:
+
+- report any [issue](${pkg.bugs})
+  you've encountered;
+- fork and create a pull request.
+
+## License
+
+${pkg.license} © [${pkg.author.name}](${pkg.author.url})

@xen-orchestra/emit-async/package.json

@@ -0,0 +1,47 @@
+{
+  "private": true,
+  "name": "@xen-orchestra/emit-async",
+  "version": "0.0.0",
+  "license": "ISC",
+  "description": "",
+  "keywords": [],
+  "homepage": "https://github.com/vatesfr/xen-orchestra/tree/master/@xen-orchestra/emit-async",
+  "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": {},
+  "devDependencies": {
+    "@babel/cli": "7.0.0",
+    "@babel/core": "7.0.0",
+    "@babel/preset-env": "7.0.0",
+    "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/emit-async/src/index.js

@@ -0,0 +1,26 @@
+export default function emitAsync (event) {
+  let opts
+  let i = 1
+
+  // an option object has been passed as first param
+  if (typeof event !== 'string') {
+    opts = event
+    event = arguments[i++]
+  }
+
+  const n = arguments.length - i
+  const args = new Array(n)
+  for (let j = 0; j < n; ++j) {
+    args[j] = arguments[j + i]
+  }
+
+  const onError = opts != null && opts.onError
+
+  return Promise.all(
+    this.listeners(event).map(listener =>
+      new Promise(resolve => {
+        resolve(listener.apply(this, args))
+      }).catch(onError)
+    )
+  )
+}

CHANGELOG.md

@@ -19,6 +19,7 @@
 
 ### Released packages
 
+- @xen-orchestra/emit-async v0.0.0
 - xo-server v5.27.0
 - xo-web v5.27.0
 

packages/xo-server/package.json

@@ -33,6 +33,7 @@
   "dependencies": {
     "@babel/polyfill": "7.0.0",
     "@xen-orchestra/cron": "^1.0.3",
+    "@xen-orchestra/emit-async": "^0.0.0",
     "@xen-orchestra/fs": "^0.3.0",
     "ajv": "^6.1.1",
     "app-conf": "^0.5.0",

packages/xo-server/src/xo-mixins/hooks.js

@@ -1,34 +1,8 @@
 import createLogger from 'debug'
+import emitAsync from '@xen-orchestra/emit-async'
 
 const debug = createLogger('xo:hooks')
 
-function emitAsync (event) {
-  let opts
-  let i = 1
-
-  // an option object has been passed as first param
-  if (typeof event !== 'string') {
-    opts = event
-    event = arguments[i++]
-  }
-
-  const n = arguments.length - i
-  const args = new Array(n)
-  for (let j = 0; j < n; ++j) {
-    args[j] = arguments[j + i]
-  }
-
-  const onError = opts != null && opts.onError
-
-  return Promise.all(
-    this.listeners(event).map(listener =>
-      new Promise(resolve => {
-        resolve(listener.apply(this, args))
-      }).catch(onError)
-    )
-  )
-}
-
 const makeSingletonHook = (hook, postEvent) => {
   let promise
   return function () {