chore: improve jest speed on both local and CI (#32096)

microsoft · Jul 25, 2024 · daafbc0 · daafbc0
1 parent 1e212a4
commit daafbc0
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Showing 5 changed files with 26 additions and 8 deletions.
diff --git a/jest.preset.js b/jest.preset.js
@@ -9,6 +9,8 @@ const tsPathAliases = pathsToModuleNameMapper(tsConfig.compilerOptions.paths, {
   prefix: `<rootDir>/${path.relative(process.cwd(), __dirname)}/`,
 });
 
+const isCI = Boolean(process.env.TF_BUILD);
+
 /**
  * @type {import('@jest/types').Config.InitialOptions}
  */
@@ -29,6 +31,17 @@ const baseConfig = {
     escapeString: true,
     printBasicPrototype: true,
   },
+  /**
+   *  **Local Machine:**
+   *
+   * jest is resource greedy. on local machine it will spawn workers into all your CPU threads which will provide additional heat up of your machine and everything else will be blocked.
+   * Based on tests on local machine, 50% of CPU threads is the best value for local development ( also the fastest).
+   *
+   *  **CI:**
+   *
+   * based on testing not spawning additional workers and rely on task orchestrator (NX) parallelization is fastest on our CI env atm ( 8 Core machine, 16GB RAM)
+   */
+  maxWorkers: isCI ? 1 : '50%',
 };
 
 module.exports = {

diff --git a/scripts/jest/src/environment.js b/scripts/jest/src/environment.js
diff --git a/scripts/jest/src/jest.preset.v0.js b/scripts/jest/src/jest.preset.v0.js
@@ -1,6 +1,5 @@
 const { getWorkspaceProjectsAliases } = require('@fluentui/scripts-monorepo');
 
-const { isCI } = require('./environment');
 const { workersConfig } = require('./shared');
 
 // northstar packages should pull these from npm, not the repo
@@ -21,7 +20,7 @@ const createConfig = (/** @type {import('@jest/types').Config.InitialOptions} */
   testEnvironment: 'jsdom',
   restoreMocks: true,
   clearMocks: true,
-  ...(isCI ? workersConfig : null),
+  ...workersConfig,
   ...customConfig,
   moduleNameMapper: {
     ...getWorkspaceProjectsAliases({

diff --git a/scripts/jest/src/jest.preset.v8.js b/scripts/jest/src/jest.preset.v8.js
@@ -4,7 +4,6 @@ const path = require('path');
 const { findRepoDeps } = require('@fluentui/scripts-monorepo');
 const { findConfig, merge } = require('@fluentui/scripts-utils');
 
-const { isCI } = require('./environment');
 const { workersConfig } = require('./shared');
 
 const packageJsonPath = findConfig('package.json') ?? '';
@@ -84,7 +83,7 @@ const createConfig = (customConfig = {}) => {
     restoreMocks: true,
     clearMocks: true,
 
-    ...(isCI ? workersConfig : null),
+    ...workersConfig,
 
     watchPlugins: ['jest-watch-typeahead/filename', 'jest-watch-typeahead/testname'],
     // OLD format for migration to jest 29 - TODO: migrate to new format . https://jestjs.io/blog/2022/04/25/jest-28#future

diff --git a/scripts/jest/src/shared.js b/scripts/jest/src/shared.js
@@ -1,3 +1,13 @@
-const workersConfig = { maxWorkers: 4 };
+/**
+ *  **Local Machine:**
+ *
+ * jest is resource greedy. on local machine it will spawn workers into all your CPU threads which will provide additional heat up of your machine and everything else will be blocked.
+ * Based on tests on local machine, 50% of CPU threads is the best value for local development ( also the fastest).
+ *
+ *  **CI:**
+ *
+ * based on testing spawning only 50% of available workers is fastest on both Local Machine and CI env atm ( 8 Core machine, 16GB RAM)
+ */
+const workersConfig = { maxWorkers: '50%' };
 
 exports.workersConfig = workersConfig;