feat: add plugin hook ordering

Author: jakobrosenberg

lib/app.js

@@ -1,6 +1,6 @@
 /// <reference path="../typedef.js" />
 
-const { deepAssign, log, keysAsFunctionsRecursive } = require('./utils')
+const { deepAssign, log, keysAsFunctionsRecursive, sortHooks } = require('./utils')
 
 
 /** @type {AppEvent[]} */
@@ -34,35 +34,36 @@ const App = class {
   merge(obj) { deepAssign(this, obj) }
   async initiate() {
     this.config.roxi = await require('./roxi').run()
+    this.config.roxi.plugins.unshift(
+      { name: 'mapper', params: {}, hooks: [{ event: 'bundle', order: { first: true }, action: app => keysAsFunctionsRecursive(app) }] },
+    )
     process.env.ROXI_LOG_LEVEL = this.config.roxi.logLevel
   }
   async run(events = this.events) {
     try {
       for (const event of events) {
-        console.log('event', event)
         this.state.event = event
         await runPlugins(event, this)
       }
     } catch (err) { this.errorHandler(err) }
   }
 }
 
-//todo move this somewhere else?
-const objToArray = {
-  hooks: [{ event: 'bundle', action: app => keysAsFunctionsRecursive(app) }]
-}
 
 /**
  * @param {AppEvent} event
  * @param {RoxiApp} app
  */
 async function runPlugins(event, app) {
-  const plugins = [objToArray, ...app.config.roxi.plugins]
-  for (const plugin of plugins) {
-    const hooks = plugin.hooks.filter(hookCondition(app, plugin.params, { event }))
-    for (const hook of hooks)
-      await app.hookHandler(app, hook, plugin, { event })
-  }
+  let hooks = []
+
+  for (const plugin of app.config.roxi.plugins)
+    plugin.hooks
+      .filter(hookCondition(app, plugin.params, { event }))
+      .forEach(hook => hooks.push({ plugin, hook }))
+
+  for (const hook of sortHooks(hooks))
+    await app.hookHandler(app, hook.hook, hook.plugin, { event })
 }
 
 /**

lib/utils/index.js

@@ -100,7 +100,62 @@ async function keysAsFunctions(obj, map, name) {
   return Promise.all(promises)
 }
 
+
+/** @param {{plugin: RoxiPlugin, hook: RoxiPluginHook}[]} hooks  */
+function sortHooks(hooks) {
+  const sortedHooks = []
+  let lastLength = null
+  let obstacles = []
+
+  while (hooks.length) {
+    if (hooks.length === lastLength)
+      throw new Error('infinite loop in hook orderings ' + JSON.stringify(obstacles, null, 2))
+    lastLength = hooks.length
+
+    for (const index in hooks) {
+      const hook = hooks[index]
+      const pluginName = hook.plugin.name
+      const orderings = [].concat(hook.hook.order || {})
+      const isFirst = orderings.find(order => order.first)
+      const isLast = orderings.find(order => order.last)
+      const runAfter = orderings.map(order => order.after).filter(Boolean)
+      const befores = orderings.map(order => order.before).filter(Boolean)
+
+      const obstacle = hooks.find((obstacleHook, _index) => {
+        // don't check against self (typeof index is string)
+        if (index == _index) return false
+
+        const obstacleOrderings = [].concat(obstacleHook.hook.order || {})
+        const obstacleIsLast = obstacleOrderings.find(order => order.last)
+        const obstacleIsFirst = obstacleOrderings.find(order => order.first)
+        const obstaclerunsAfter = obstacleOrderings.map(order => order.after).filter(Boolean)
+
+        if (
+          runAfter.includes(obstacleHook.plugin.name)
+          || (isLast && !obstacleIsLast && !obstaclerunsAfter.includes(pluginName))
+          || (obstacleIsFirst && !isFirst && !befores.includes(obstacleHook.plugin.name))
+          || obstacleOrderings.find(order => order.before === pluginName)
+        )
+          return true
+    })
+
+    if (obstacle) {
+      obstacles.push({
+        plugin: hook.plugin.name,
+        obstacle: obstacle.plugin.name
+      })
+    } else {
+      sortedHooks.push(hooks.splice(index, 1)[0])
+      break;
+    }
+  }
+}
+return sortedHooks
+}
+
+
 module.exports = {
+  sortHooks,
   normalizePluginConfig,
   isObject,
   deepAssign,

lib/utils/tests/sortHooks.spec.js

@@ -0,0 +1,35 @@
+const { sortHooks } = require("..");
+
+const hooks = [
+  { hook: { order: [] }, plugin: { name: 'pluginB' } },
+  { hook: { order: [] }, plugin: { name: 'pluginD' } },
+  { hook: { order: { before: 'pluginD' } }, plugin: { name: 'pluginC' } },
+  { hook: { order: [] }, plugin: { name: 'pluginE' } },
+  { hook: { order: [{ after: 'pluginG' }] }, plugin: { name: 'pluginH' } },
+  { hook: { order: [] }, plugin: { name: 'pluginF' } },
+  { hook: { order: [{ last: true }] }, plugin: { name: 'last1' } },
+  { hook: { order: [{ last: true }] }, plugin: { name: 'last2' } },
+  { hook: { order: [{ after: 'last1' }] }, plugin: { name: 'afterLast1' } },
+  { hook: { order: [] }, plugin: { name: 'pluginG' } },
+  { hook: { order: { first: true } }, plugin: { name: 'first' } },
+  { hook: { order: { before: 'first' } }, plugin: { name: 'beforeFirst' } },
+]
+
+it('sorts hooks', () => {
+  const sortedHooks = sortHooks(hooks)
+
+  expect(sortedHooks.map(hook => hook.plugin.name)).toEqual([
+    'beforeFirst', 'first', 'pluginB', 'pluginC', 'pluginD', 'pluginE', 'pluginF', 'pluginG', 'pluginH',
+    'last1',
+    'afterLast1',
+    'last2',
+  ])
+})
+
+it('throws error for infinite loops', () => {
+  const breaker1 = { hook: { order: [{ before: 'beforeBreaker2' }] }, plugin: { name: 'beforeBreaker1' } }
+  const breaker2 = { hook: { order: [{ before: 'beforeBreaker1' }] }, plugin: { name: 'beforeBreaker2' } }
+  expect(()=>{
+    sortHooks([...hooks, breaker1, breaker2])
+  }).toThrow('infinite loop')
+})

typedef.js

@@ -3,6 +3,12 @@
  * |'after:config'|'before:bundle'|'bundle'
  * |'after:bundle'|'router'|'end'} AppEvent
  *
+ * @typedef {object} HookOrder
+ * @prop {string=} before
+ * @prop {string=} after
+ * @prop {boolean=} first
+ * @prop {boolean=} last
+ *
  * @typedef {object} RoxiPlugin
  * @prop {string=} name
  * @prop {RoxiPluginHook[]} hooks
@@ -12,6 +18,7 @@
  * @prop {AppEvent} event
  * @prop {string=} name
  * @prop {RoxiPluginHookFunction|string=} condition
+ * @prop {HookOrder|HookOrder[]=} order
  * @prop {RoxiPluginHookFunction} action
  *
  * @callback RoxiPluginHookFunction