chore: hoist functions higher if possible (#14812)

.eslintrc.cjs

@@ -236,6 +236,7 @@ module.exports = {
         'sort-keys': 'off',
         'unicorn/prefer-number-properties': 'off',
         'unicorn/no-static-only-class': 'off',
+        'unicorn/consistent-function-scoping': 'off',
       },
     },
     // demonstration of matchers usage
@@ -344,6 +345,7 @@ module.exports = {
       ],
       rules: {
         '@typescript-eslint/explicit-module-boundary-types': 'off',
+        'unicorn/consistent-function-scoping': 'off',
       },
     },
     {
@@ -378,6 +380,7 @@ module.exports = {
       ],
       rules: {
         'import/no-extraneous-dependencies': 'off',
+        'unicorn/consistent-function-scoping': 'off',
       },
     },
     {
@@ -706,7 +709,6 @@ module.exports = {
 
     // TODO: turn on at some point
     'unicorn/catch-error-name': 'off',
-    'unicorn/consistent-function-scoping': 'off',
     'unicorn/error-message': 'off',
     'unicorn/no-await-expression-member': 'off',
     'unicorn/no-console-spaces': 'off',

e2e/__tests__/__snapshots__/testFailingJasmine.test.ts.snap

@@ -46,7 +46,7 @@ FAIL __tests__/worksWithConcurrentMode.test.js
       15 |   });
       16 |
 
-      at Function.failing (../../packages/jest-jasmine2/build/index.js:305:17)
+      at Function.failing (../../packages/jest-jasmine2/build/index.js:307:17)
       at Suite.failing (__tests__/worksWithConcurrentMode.test.js:13:17)
       at Object.describe (__tests__/worksWithConcurrentMode.test.js:8:1)
 
@@ -80,7 +80,7 @@ FAIL __tests__/worksWithConcurrentOnlyMode.test.js
       15 |   });
       16 |
 
-      at Function.failing (../../packages/jest-jasmine2/build/index.js:305:17)
+      at Function.failing (../../packages/jest-jasmine2/build/index.js:307:17)
       at Suite.failing (__tests__/worksWithConcurrentOnlyMode.test.js:13:22)
       at Object.describe (__tests__/worksWithConcurrentOnlyMode.test.js:8:1)
 

examples/angular/tsconfig.json

@@ -1,5 +1,8 @@
 {
+  "extends": "../../tsconfig.json",
   "compilerOptions": {
+    "emitDeclarationOnly": false,
+    "noEmit": true,
     "experimentalDecorators": true,
     "strict": true
   },

examples/expect-extend/tsconfig.json

@@ -1,5 +1,8 @@
 {
+  "extends": "../../tsconfig.json",
   "compilerOptions": {
+    "emitDeclarationOnly": false,
+    "noEmit": true,
     "strict": true
   },
   "include": ["./**/*"]

examples/typescript/tsconfig.json

@@ -1,6 +1,9 @@
 {
   "compilerOptions": {
+    "target": "ESNext",
+    "noEmit": true,
     "module": "commonjs",
     "jsx": "react-jsx"
-  }
+  },
+  "include": ["./**/*"]
 }

package.json

@@ -115,7 +115,7 @@
     "test-types": "yarn tstyche && yarn test-ts --selectProjects type-tests",
     "test": "yarn lint && yarn jest",
     "typecheck": "yarn typecheck:examples && yarn typecheck:tests",
-    "typecheck:examples": "tsc -p examples/angular --noEmit && tsc -p examples/expect-extend --noEmit && tsc -p examples/typescript --noEmit",
+    "typecheck:examples": "tsc -p examples/angular && tsc -p examples/expect-extend && tsc -p examples/typescript",
     "typecheck:tests": "tsc -b packages/{babel-jest,babel-plugin-jest-hoist,create-jest,diff-sequences,expect,expect-utils,jest-circus,jest-cli,jest-config,jest-console,jest-snapshot,jest-util,jest-validate,jest-watcher,jest-worker,pretty-format}/**/__tests__",
     "verify-old-ts": "node ./scripts/verifyOldTs.mjs",
     "verify-pnp": "node ./scripts/verifyPnP.mjs",

packages/babel-plugin-jest-hoist/src/index.ts

@@ -313,6 +313,52 @@ const extractJestObjExprIfHoistable = (expr: NodePath): JestObjInfo | null => {
   return null;
 };
 
+function visitBlock(block: NodePath<BlockStatement> | NodePath<Program>) {
+  // use a temporary empty statement instead of the real first statement, which may itself be hoisted
+  const [varsHoistPoint, callsHoistPoint] = block.unshiftContainer('body', [
+    emptyStatement(),
+    emptyStatement(),
+  ]);
+  block.traverse({
+    CallExpression: visitCallExpr,
+    VariableDeclarator: visitVariableDeclarator,
+    // do not traverse into nested blocks, or we'll hoist calls in there out to this block
+    denylist: ['BlockStatement'],
+  });
+  callsHoistPoint.remove();
+  varsHoistPoint.remove();
+
+  function visitCallExpr(callExpr: NodePath<CallExpression>) {
+    if (hoistedJestGetters.has(callExpr.node)) {
+      const mockStmt = callExpr.getStatementParent();
+
+      if (mockStmt) {
+        const mockStmtParent = mockStmt.parentPath;
+        if (mockStmtParent.isBlock()) {
+          const mockStmtNode = mockStmt.node;
+          mockStmt.remove();
+          callsHoistPoint.insertBefore(mockStmtNode);
+        }
+      }
+    }
+  }
+
+  function visitVariableDeclarator(varDecl: NodePath<VariableDeclarator>) {
+    if (hoistedVariables.has(varDecl.node)) {
+      // should be assert function, but it's not. So let's cast below
+      varDecl.parentPath.assertVariableDeclaration();
+
+      const {kind, declarations} = varDecl.parent as VariableDeclaration;
+      if (declarations.length === 1) {
+        varDecl.parentPath.remove();
+      } else {
+        varDecl.remove();
+      }
+      varsHoistPoint.insertBefore(variableDeclaration(kind, [varDecl.node]));
+    }
+  }
+}
+
 /* eslint-disable sort-keys */
 export default function jestHoist(): PluginObj<{
   declareJestObjGetterIdentifier: () => Identifier;
@@ -360,56 +406,6 @@ export default function jestHoist(): PluginObj<{
     post({path: program}) {
       visitBlock(program);
       program.traverse({BlockStatement: visitBlock});
-
-      function visitBlock(block: NodePath<BlockStatement> | NodePath<Program>) {
-        // use a temporary empty statement instead of the real first statement, which may itself be hoisted
-        const [varsHoistPoint, callsHoistPoint] = block.unshiftContainer(
-          'body',
-          [emptyStatement(), emptyStatement()],
-        );
-        block.traverse({
-          CallExpression: visitCallExpr,
-          VariableDeclarator: visitVariableDeclarator,
-          // do not traverse into nested blocks, or we'll hoist calls in there out to this block
-          denylist: ['BlockStatement'],
-        });
-        callsHoistPoint.remove();
-        varsHoistPoint.remove();
-
-        function visitCallExpr(callExpr: NodePath<CallExpression>) {
-          if (hoistedJestGetters.has(callExpr.node)) {
-            const mockStmt = callExpr.getStatementParent();
-
-            if (mockStmt) {
-              const mockStmtParent = mockStmt.parentPath;
-              if (mockStmtParent.isBlock()) {
-                const mockStmtNode = mockStmt.node;
-                mockStmt.remove();
-                callsHoistPoint.insertBefore(mockStmtNode);
-              }
-            }
-          }
-        }
-
-        function visitVariableDeclarator(
-          varDecl: NodePath<VariableDeclarator>,
-        ) {
-          if (hoistedVariables.has(varDecl.node)) {
-            // should be assert function, but it's not. So let's cast below
-            varDecl.parentPath.assertVariableDeclaration();
-
-            const {kind, declarations} = varDecl.parent as VariableDeclaration;
-            if (declarations.length === 1) {
-              varDecl.parentPath.remove();
-            } else {
-              varDecl.remove();
-            }
-            varsHoistPoint.insertBefore(
-              variableDeclaration(kind, [varDecl.node]),
-            );
-          }
-        }
-      }
     },
   };
 }

packages/expect/src/spyMatchers.ts

@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+/* eslint-disable unicorn/consistent-function-scoping */
+
 import {equals, iterableEquality} from '@jest/expect-utils';
 import {getType, isPrimitive} from 'jest-get-type';
 import {

packages/jest-config/src/normalize.ts

@@ -426,6 +426,12 @@ const buildTestPathPatterns = (
   return testPathPatterns;
 };
 
+function printConfig(opts: Array<string>) {
+  const string = opts.map(ext => `'${ext}'`).join(', ');
+
+  return chalk.bold(`extensionsToTreatAsEsm: [${string}]`);
+}
+
 function validateExtensionsToTreatAsEsm(
   extensionsToTreatAsEsm: Config.InitialOptions['extensionsToTreatAsEsm'],
 ) {
@@ -433,12 +439,6 @@ function validateExtensionsToTreatAsEsm(
     return;
   }
 
-  function printConfig(opts: Array<string>) {
-    const string = opts.map(ext => `'${ext}'`).join(', ');
-
-    return chalk.bold(`extensionsToTreatAsEsm: [${string}]`);
-  }
-
   const extensionWithoutDot = extensionsToTreatAsEsm.some(
     ext => !ext.startsWith('.'),
   );

packages/jest-core/src/SearchSource.ts

@@ -54,6 +54,10 @@ const hasSCM = (changedFilesInfo: ChangedFiles) => {
   return !noSCM;
 };
 
+function normalizePosix(filePath: string) {
+  return filePath.replace(/\\/g, '/');
+}
+
 export default class SearchSource {
   private readonly _context: TestContext;
   private _dependencyResolver: DependencyResolver | null;
@@ -299,10 +303,6 @@ export default class SearchSource {
     const allFiles = this._context.hasteFS.getAllFiles();
     const options = {nocase: true, windows: false};
 
-    function normalizePosix(filePath: string) {
-      return filePath.replace(/\\/g, '/');
-    }
-
     paths = paths
       .map(p => {
         // micromatch works with forward slashes: https://github.com/micromatch/micromatch#backslashes

packages/jest-core/src/getConfigsOfProjectsToRun.ts

@@ -22,14 +22,14 @@ export default function getConfigsOfProjectsToRun(
   });
 }
 
+const always = () => true;
+
 function createProjectFilter(opts: {
   ignoreProjects: Array<string> | undefined;
   selectProjects: Array<string> | undefined;
 }) {
   const {selectProjects, ignoreProjects} = opts;
 
-  const always = () => true;
-
   const selected = selectProjects
     ? (name: string | undefined) => name && selectProjects.includes(name)
     : always;

packages/jest-environment-node/src/index.ts

@@ -60,6 +60,18 @@ function isString(value: unknown): value is string {
   return typeof value === 'string';
 }
 
+const timerIdToRef = (id: number) => ({
+  id,
+  ref() {
+    return this;
+  },
+  unref() {
+    return this;
+  },
+});
+
+const timerRefToId = (timer: Timer): number | undefined => timer?.id;
+
 export default class NodeEnvironment implements JestEnvironment<Timer> {
   context: Context | null;
   fakeTimers: LegacyFakeTimers<Timer> | null;
@@ -159,18 +171,6 @@ export default class NodeEnvironment implements JestEnvironment<Timer> {
 
     this.moduleMocker = new ModuleMocker(global);
 
-    const timerIdToRef = (id: number) => ({
-      id,
-      ref() {
-        return this;
-      },
-      unref() {
-        return this;
-      },
-    });
-
-    const timerRefToId = (timer: Timer): number | undefined => timer?.id;
-
     this.fakeTimers = new LegacyFakeTimers({
       config: projectConfig,
       global,

packages/jest-fake-timers/src/legacyFakeTimers.ts

@@ -431,11 +431,16 @@ export default class FakeTimers<TimerRef = unknown> {
     }
   }
 
-  private _createMocks() {
-    const fn = <T extends FunctionLike = UnknownFunction>(implementation?: T) =>
-      this._moduleMocker.fn(implementation);
+  #createMockFunction<T extends FunctionLike = UnknownFunction>(
+    implementation: T,
+  ) {
+    return this._moduleMocker.fn(implementation.bind(this));
+  }
 
-    const promisifiableFakeSetTimeout = fn(this._fakeSetTimeout.bind(this));
+  private _createMocks() {
+    const promisifiableFakeSetTimeout = this.#createMockFunction(
+      this._fakeSetTimeout,
+    );
     // @ts-expect-error: no index
     promisifiableFakeSetTimeout[promisify.custom] = (
       delay?: number,
@@ -444,14 +449,16 @@ export default class FakeTimers<TimerRef = unknown> {
       new Promise(resolve => promisifiableFakeSetTimeout(resolve, delay, arg));
 
     this._fakeTimerAPIs = {
-      cancelAnimationFrame: fn(this._fakeClearTimer.bind(this)),
-      clearImmediate: fn(this._fakeClearImmediate.bind(this)),
-      clearInterval: fn(this._fakeClearTimer.bind(this)),
-      clearTimeout: fn(this._fakeClearTimer.bind(this)),
-      nextTick: fn(this._fakeNextTick.bind(this)),
-      requestAnimationFrame: fn(this._fakeRequestAnimationFrame.bind(this)),
-      setImmediate: fn(this._fakeSetImmediate.bind(this)),
-      setInterval: fn(this._fakeSetInterval.bind(this)),
+      cancelAnimationFrame: this.#createMockFunction(this._fakeClearTimer),
+      clearImmediate: this.#createMockFunction(this._fakeClearImmediate),
+      clearInterval: this.#createMockFunction(this._fakeClearTimer),
+      clearTimeout: this.#createMockFunction(this._fakeClearTimer),
+      nextTick: this.#createMockFunction(this._fakeNextTick),
+      requestAnimationFrame: this.#createMockFunction(
+        this._fakeRequestAnimationFrame,
+      ),
+      setImmediate: this.#createMockFunction(this._fakeSetImmediate),
+      setInterval: this.#createMockFunction(this._fakeSetInterval),
       setTimeout: promisifiableFakeSetTimeout,
     };
   }

packages/jest-jasmine2/src/jasmineAsyncInstall.ts

@@ -230,6 +230,7 @@ function makeConcurrent(
     return spec;
   };
 
+  // eslint-disable-next-line unicorn/consistent-function-scoping
   const failing = () => {
     throw new Error(
       'Jest: `failing` tests are only supported in `jest-circus`.',
@@ -242,7 +243,7 @@ function makeConcurrent(
     );
   };
   // each is bound after the function is made concurrent, so for now it is made noop
-  // eslint-disable-next-line @typescript-eslint/no-empty-function
+  // eslint-disable-next-line @typescript-eslint/no-empty-function,unicorn/consistent-function-scoping
   concurrentFn.each = () => () => {};
   concurrentFn.failing = failing;
 

packages/jest-jasmine2/src/treeProcessor.ts

@@ -28,6 +28,20 @@ export type TreeNode = {
 // eslint-disable-next-line @typescript-eslint/no-empty-function
 const noop = () => {};
 
+function getNodeWithoutChildrenHandler(node: TreeNode, enabled: boolean) {
+  return function fn(done: (error?: unknown) => void = noop) {
+    node.execute(done, enabled);
+  };
+}
+
+function hasNoEnabledTest(node: TreeNode): boolean {
+  return (
+    node.disabled ||
+    node.markedPending ||
+    (node.children?.every(hasNoEnabledTest) ?? false)
+  );
+}
+
 export default function treeProcessor(options: Options): void {
   const {nodeComplete, nodeStart, queueRunnerFactory, runnableIds, tree} =
     options;
@@ -43,12 +57,6 @@ export default function treeProcessor(options: Options): void {
       : getNodeWithoutChildrenHandler(node, enabled);
   }
 
-  function getNodeWithoutChildrenHandler(node: TreeNode, enabled: boolean) {
-    return function fn(done: (error?: unknown) => void = noop) {
-      node.execute(done, enabled);
-    };
-  }
-
   function getNodeWithChildrenHandler(node: TreeNode, enabled: boolean) {
     return async function fn(done: (error?: unknown) => void = noop) {
       nodeStart(node);
@@ -62,14 +70,6 @@ export default function treeProcessor(options: Options): void {
     };
   }
 
-  function hasNoEnabledTest(node: TreeNode): boolean {
-    return (
-      node.disabled ||
-      node.markedPending ||
-      (node.children?.every(hasNoEnabledTest) ?? false)
-    );
-  }
-
   function wrapChildren(node: TreeNode, enabled: boolean) {
     if (!node.children) {
       throw new Error('`node.children` is not defined.');

packages/jest-runner/src/index.ts

@@ -72,13 +72,6 @@ export default class TestRunner extends EmittingTestRunner {
                 throw new CancelRun();
               }
 
-              // `deepCyclicCopy` used here to avoid mem-leak
-              const sendMessageToJest: TestFileEvent = (eventName, args) =>
-                this.#eventEmitter.emit(
-                  eventName,
-                  deepCyclicCopy(args, {keepPrototype: false}),
-                );
-
               await this.#eventEmitter.emit('test-file-start', [test]);
 
               return runTest(
@@ -87,7 +80,7 @@ export default class TestRunner extends EmittingTestRunner {
                 test.context.config,
                 test.context.resolver,
                 this._context,
-                sendMessageToJest,
+                this.#sendMessageToJest,
               );
             })
             .then(
@@ -208,6 +201,14 @@ export default class TestRunner extends EmittingTestRunner {
   ): UnsubscribeFn {
     return this.#eventEmitter.on(eventName, listener);
   }
+
+  #sendMessageToJest: TestFileEvent = async (eventName, args) => {
+    await this.#eventEmitter.emit(
+      eventName,
+      // `deepCyclicCopy` used here to avoid mem-leak
+      deepCyclicCopy(args, {keepPrototype: false}),
+    );
+  };
 }
 
 class CancelRun extends Error {

packages/jest-runtime/src/index.ts

@@ -1819,6 +1819,7 @@ export default class Runtime {
       return this._moduleImplementation;
     }
 
+    // eslint-disable-next-line unicorn/consistent-function-scoping
     const createRequire = (modulePath: string | URL) => {
       const filename =
         typeof modulePath === 'string'
@@ -2195,6 +2196,7 @@ export default class Runtime {
       this.restoreAllMocks();
       return jestObject;
     };
+    // eslint-disable-next-line unicorn/consistent-function-scoping
     const _getFakeTimers = () => {
       if (
         this.isTornDown ||
@@ -2238,9 +2240,7 @@ export default class Runtime {
       this.isolateModules(fn);
       return jestObject;
     };
-    const isolateModulesAsync = (fn: () => Promise<void>): Promise<void> => {
-      return this.isolateModulesAsync(fn);
-    };
+    const isolateModulesAsync = this.isolateModulesAsync.bind(this);
     const fn = this._moduleMocker.fn.bind(this._moduleMocker);
     const spyOn = this._moduleMocker.spyOn.bind(this._moduleMocker);
     const mocked =

website/src/pages/animations/_landingAnimation.js

@@ -5,6 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+function cardTransform(offset, handWidth) {
+  const transform = `rotate(${offset * 4}deg) translateX(${
+    (offset - (Math.abs(offset) * offset) / 7) * Math.min(140, handWidth / 8)
+  }px)`;
+  return transform;
+}
+
 // Docusaurus v1 animation, reworked a bit for the Docusaurus v2 migration
 // TODO maybe we can use React code instead of Vanilla JS now?
 export function setupLandingAnimation() {
@@ -17,13 +24,6 @@ export function setupLandingAnimation() {
   const hand = document.querySelector('.jest-hand');
   const cards = hand.querySelectorAll('.jest-card');
 
-  function cardTransform(offset, handWidth) {
-    const transform = `rotate(${offset * 4}deg) translateX(${
-      (offset - (Math.abs(offset) * offset) / 7) * Math.min(140, handWidth / 8)
-    }px)`;
-    return transform;
-  }
-
   function positionCards() {
     const handWidth = hand.offsetWidth;
     for (const card of cards) {