forked from prebid/Prebid.js
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
New hooks API (replaces monkey-patching for currency) (prebid#1683)
* added hook module to prebid core that allows extension of arbitrary functions * remove unused dependency tiny-queue * change PluginFunction to HookedFunction * more hook documentation fixes * allow context for hooked functions * added tests for context * remove withContext, just use bind * fix in hooks so asyncSeries keeps proper bound context
- Loading branch information
Showing
5 changed files
with
283 additions
and
78 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,78 @@ | ||
|
|
||
| /** | ||
| * @typedef {function} HookedFunction | ||
| * @property {function(function(), [number])} addHook A method that takes a new function to attach as a hook | ||
| * to the HookedFunction | ||
| * @property {function(function())} removeHook A method to remove attached hooks | ||
| */ | ||
|
|
||
| /** | ||
| * A map of global hook methods to allow easy extension of hooked functions that are intended to be extended globally | ||
| * @type {{}} | ||
| */ | ||
| export const hooks = {}; | ||
|
|
||
| /** | ||
| * A utility function for allowing a regular function to be extensible with additional hook functions | ||
| * @param {string} type The method for applying all attached hooks when this hooked function is called | ||
| * @param {function()} fn The function to make hookable | ||
| * @param {string} hookName If provided this allows you to register a name for a global hook to have easy access to | ||
| * the addHook and removeHook methods for that hook (which are usually accessed as methods on the function itself) | ||
| * @returns {HookedFunction} A new function that implements the HookedFunction interface | ||
| */ | ||
| export function createHook(type, fn, hookName) { | ||
| let _hooks = [{fn, priority: 0}]; | ||
|
|
||
| let types = { | ||
| sync: function(...args) { | ||
| _hooks.forEach(hook => { | ||
| hook.fn.apply(this, args); | ||
| }); | ||
| }, | ||
| asyncSeries: function(...args) { | ||
| let curr = 0; | ||
|
|
||
| const asyncSeriesNext = (...args) => { | ||
| let hook = _hooks[++curr]; | ||
| if (typeof hook === 'object' && typeof hook.fn === 'function') { | ||
| return hook.fn.apply(this, args.concat(asyncSeriesNext)) | ||
| } | ||
| }; | ||
|
|
||
| return _hooks[curr].fn.apply(this, args.concat(asyncSeriesNext)); | ||
| } | ||
| }; | ||
|
|
||
| if (!types[type]) { | ||
| throw 'invalid hook type'; | ||
| } | ||
|
|
||
| let methods = { | ||
| addHook: function(fn, priority = 10) { | ||
| if (typeof fn === 'function') { | ||
| _hooks.push({ | ||
| fn, | ||
| priority: priority | ||
| }); | ||
|
|
||
| _hooks.sort((a, b) => b.priority - a.priority); | ||
| } | ||
| }, | ||
| removeHook: function(removeFn) { | ||
| _hooks = _hooks.filter(hook => hook.fn === fn || hook.fn !== removeFn); | ||
| } | ||
| }; | ||
|
|
||
| if (typeof hookName === 'string') { | ||
| hooks[hookName] = methods; | ||
| } | ||
|
|
||
| function hookedFn(...args) { | ||
| if (_hooks.length === 0) { | ||
| return fn.apply(this, args); | ||
| } | ||
| return types[type].apply(this, args); | ||
| } | ||
|
|
||
| return Object.assign(hookedFn, methods); | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,151 @@ | ||
|
|
||
| import { expect } from 'chai'; | ||
| import { createHook, hooks } from 'src/hook'; | ||
|
|
||
| describe('the hook module', () => { | ||
| let sandbox; | ||
|
|
||
| beforeEach(() => { | ||
| sandbox = sinon.sandbox.create(); | ||
| }); | ||
|
|
||
| afterEach(() => { | ||
| sandbox.restore(); | ||
| }); | ||
|
|
||
| it('should call all sync hooks attached to a function', () => { | ||
| let called = []; | ||
| let calledWith; | ||
|
|
||
| let testFn = () => { | ||
| called.push(testFn); | ||
| }; | ||
| let testHook = (...args) => { | ||
| called.push(testHook); | ||
| calledWith = args; | ||
| }; | ||
| let testHook2 = () => { | ||
| called.push(testHook2); | ||
| }; | ||
| let testHook3 = () => { | ||
| called.push(testHook3); | ||
| }; | ||
|
|
||
| let hookedTestFn = createHook('sync', testFn, 'testHook'); | ||
|
|
||
| hookedTestFn.addHook(testHook, 50); | ||
| hookedTestFn.addHook(testHook2, 100); | ||
|
|
||
| // make sure global test hooks work as well (with default priority) | ||
| hooks['testHook'].addHook(testHook3); | ||
|
|
||
| hookedTestFn(1, 2, 3); | ||
|
|
||
| expect(called).to.deep.equal([ | ||
| testHook2, | ||
| testHook, | ||
| testHook3, | ||
| testFn | ||
| ]); | ||
|
|
||
| expect(calledWith).to.deep.equal([1, 2, 3]); | ||
|
|
||
| called = []; | ||
|
|
||
| hookedTestFn.removeHook(testHook); | ||
| hooks['testHook'].removeHook(testHook3); | ||
|
|
||
| hookedTestFn(1, 2, 3); | ||
|
|
||
| expect(called).to.deep.equal([ | ||
| testHook2, | ||
| testFn | ||
| ]); | ||
| }); | ||
|
|
||
| it('should allow context to be passed to hooks, but keep bound contexts', () => { | ||
| let context; | ||
| let fn = function() { | ||
| context = this; | ||
| }; | ||
|
|
||
| let boundContext = {}; | ||
| let calledBoundContext; | ||
| let hook = function() { | ||
| calledBoundContext = this; | ||
| }.bind(boundContext); | ||
|
|
||
| let hookFn = createHook('sync', fn); | ||
| hookFn.addHook(hook); | ||
|
|
||
| let newContext = {}; | ||
| hookFn.bind(newContext)(); | ||
|
|
||
| expect(context).to.equal(newContext); | ||
| expect(calledBoundContext).to.equal(boundContext); | ||
| }); | ||
|
|
||
| describe('asyncSeries', () => { | ||
| it('should call function as normal if no hooks attached', () => { | ||
| let fn = sandbox.spy(); | ||
| let hookFn = createHook('asyncSeries', fn); | ||
|
|
||
| hookFn(1); | ||
|
|
||
| expect(fn.calledOnce).to.equal(true); | ||
| expect(fn.firstCall.args[0]).to.equal(1); | ||
| }); | ||
|
|
||
| it('should call hooks correctly applied in asyncSeries', () => { | ||
| let called = []; | ||
|
|
||
| let testFn = (called) => { | ||
| called.push(testFn); | ||
| }; | ||
| let testHook = (called, next) => { | ||
| called.push(testHook); | ||
| next(called); | ||
| }; | ||
| let testHook2 = (called, next) => { | ||
| called.push(testHook2); | ||
| next(called); | ||
| }; | ||
|
|
||
| let hookedTestFn = createHook('asyncSeries', testFn); | ||
| hookedTestFn.addHook(testHook); | ||
| hookedTestFn.addHook(testHook2); | ||
|
|
||
| hookedTestFn(called); | ||
|
|
||
| expect(called).to.deep.equal([ | ||
| testHook, | ||
| testHook2, | ||
| testFn | ||
| ]); | ||
| }); | ||
|
|
||
| it('should allow context to be passed to hooks, but keep bound contexts', () => { | ||
| let context; | ||
| let fn = function() { | ||
| context = this; | ||
| }; | ||
|
|
||
| let boundContext1 = {}; | ||
| let calledBoundContext1; | ||
| let hook1 = function(next) { | ||
| calledBoundContext1 = this; | ||
| next() | ||
| }.bind(boundContext1); | ||
|
|
||
| let hookFn = createHook('asyncSeries', fn); | ||
| hookFn.addHook(hook1); | ||
|
|
||
| let newContext = {}; | ||
| hookFn = hookFn.bind(newContext); | ||
| hookFn(); | ||
|
|
||
| expect(context).to.equal(newContext); | ||
| expect(calledBoundContext1).to.equal(boundContext1); | ||
| }); | ||
| }); | ||
| }); |
Oops, something went wrong.