feat(config): add support for workers config option

Allows to limit maximum amount of workers run in parallel during testing. Should help running tests on servers with a lot of cpu cores (i.e. CI agent), as worker-farm (that is used for managing workers) use os.cpus().length as a default value
gemini-testing · Jun 25, 2019 · d7b7710 · d7b7710
1 parent a5e8aef
commit d7b7710
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Showing 9 changed files with 22 additions and 10 deletions.
diff --git a/doc/config.md b/doc/config.md
@@ -65,6 +65,7 @@ system:
     teamcity: true
   debug: true
   parallelLimit: 3
+  workers: 4
   diffColor: '#ff0000'
   coverage:
     enabled: true
@@ -125,6 +126,9 @@ exclude:
   option to limit the number of browsers that `gemini` will try to run in
   parallel.
 
+* `workers` — by default, `gemini` will run as many parallel
+  workers as cores available, this option allows you to limit it.
+
 * `diffColor` — specifies color which will be used to highlight differences
   between images. Specified in hexadecimal RGB (`#RRGGBB`). Magenta by default
   (`#FF00FF`).

diff --git a/lib/config/options.js b/lib/config/options.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const os = require('os');
 const path = require('path');
 const configparser = require('gemini-configparser');
 const _ = require('lodash');
@@ -45,6 +46,8 @@ module.exports = root(
 
             parallelLimit: positiveIntegerOption(Infinity),
 
+            workers: positiveIntegerOption(os.cpus().length),
+
             diffColor: option({
                 defaultValue: '#ff00ff',
                 validate: (value) => {

diff --git a/lib/gemini.js b/lib/gemini.js
@@ -82,7 +82,7 @@ module.exports = class Gemini extends PassthroughEmitter {
     }
 
     update(paths, options) {
-        return this._exec(() => this._run(StateProcessor.createScreenUpdater(options), paths, options));
+        return this._exec(() => this._run(StateProcessor.createScreenUpdater(this.config, options), paths, options));
     }
 
     test(paths, options) {

diff --git a/lib/state-processor/index.js b/lib/state-processor/index.js
@@ -8,7 +8,7 @@ module.exports = {
         return new TestStateProcessor(config);
     },
 
-    createScreenUpdater: function(options) {
-        return new UpdateStateProcessor(options);
+    createScreenUpdater: function(config, options) {
+        return new UpdateStateProcessor(config, options);
     }
 };
diff --git a/lib/state-processor/state-processor.js b/lib/state-processor/state-processor.js
@@ -9,12 +9,16 @@ const Events = require('../constants/events');
 const errorUtils = require('../errors/utils');
 
 module.exports = class StateProcessor {
-    constructor(captureProcessorType) {
+    constructor(captureProcessorType, maxConcurrentWorkers) {
         this._captureProcessorType = captureProcessorType;
+        this._maxConcurrentWorkers = maxConcurrentWorkers;
     }
 
     prepare(emitter) {
-        this._workers = workerFarm(require.resolve('./job'));
+        const workerFarmConfig = {
+            maxConcurrentWorkers: this._maxConcurrentWorkers
+        };
+        this._workers = workerFarm(workerFarmConfig, require.resolve('./job'));
         emitter.on(Events.END, () => workerFarm.end(this._workers));
     }
 

diff --git a/lib/state-processor/test-state-processor.js b/lib/state-processor/test-state-processor.js
@@ -8,7 +8,7 @@ const {Image} = require('gemini-core');
 
 module.exports = class TestStateProcessor extends StateProcessor {
     constructor(config) {
-        super('tester');
+        super('tester', config.system.workers);
 
         this._diffColor = config.system.diffColor;
     }

diff --git a/lib/state-processor/update-state-processor.js b/lib/state-processor/update-state-processor.js
@@ -4,12 +4,12 @@ const StateProcessor = require('./state-processor');
 const Events = require('../constants/events');
 
 module.exports = class UpdateStateProcessor extends StateProcessor {
-    constructor(opts) {
+    constructor(config, opts) {
         const updaterType = opts.diff && !opts.new && 'diff-updater'
             || !opts.diff && opts.new && 'new-updater'
             || 'meta-updater';
 
-        super(updaterType);
+        super(updaterType, config.system.workers);
     }
 
     exec(state, browserSession, page, emit) {

diff --git a/test/unit/state-processor/state-processor.js b/test/unit/state-processor/state-processor.js
@@ -38,7 +38,7 @@ describe('state-processor/state-processor', () => {
                     return (args, cb) => cb(null, job(args));
                 }
             });
-            const stateProcessor = new StateProcessor(opts.captureProcessorType);
+            const stateProcessor = new StateProcessor(opts.captureProcessorType, 4);
 
             stateProcessor.prepare(new AsyncEmitter());
             return stateProcessor.exec(opts.state, browserSession, opts.page);

diff --git a/test/unit/state-processor/update-state-processor.js b/test/unit/state-processor/update-state-processor.js
@@ -10,6 +10,7 @@ const util = require('../../util');
 
 describe('state-processor/update-state-processor', () => {
     const sandbox = sinon.sandbox.create();
+    const config = {system: {workers: 4}};
 
     const exec_ = (opts) => {
         opts = _.defaultsDeep(opts || {}, {
@@ -19,7 +20,7 @@ describe('state-processor/update-state-processor', () => {
             emit: sinon.spy()
         });
 
-        return new UpdateStateProcessor({}).exec(opts.state, opts.browserSession, opts.page, opts.emit);
+        return new UpdateStateProcessor(config, {}).exec(opts.state, opts.browserSession, opts.page, opts.emit);
     };
 
     beforeEach(() => sandbox.stub(StateProcessor.prototype, 'exec'));