chore: handle non-iterable arrays in test environment

.eslintrc.js

@@ -100,6 +100,12 @@ module.exports = {
         'import/no-extraneous-dependencies': 0,
       },
     },
+    {
+      files: ['packages/jest-jasmine2/**', 'packages/jest-circus/**'],
+      rules: {
+        'no-array-constructor': 0,
+      },
+    },
   ],
   parser: 'babel-eslint',
   plugins: ['markdown', 'import', 'prettier'],

packages/jest-circus/src/eventHandler.ts

@@ -111,10 +111,10 @@ const eventHandler: EventHandler = (event, state): void => {
       } else if (type === 'afterAll') {
         // Attaching `afterAll` errors to each test makes execution flow
         // too complicated, so we'll consider them to be global.
-        state.unhandledErrors.push([error, asyncError]);
+        state.unhandledErrors.push(new Array(error, asyncError));
       } else {
         invariant(test, 'always present for `*Each` hooks');
-        test!.errors.push([error, asyncError]);
+        test!.errors.push(new Array(error, asyncError));
       }
       break;
     }
@@ -143,11 +143,11 @@ const eventHandler: EventHandler = (event, state): void => {
         error,
         test: {asyncError},
       } = event;
-      event.test.errors.push([error, asyncError]);
+      event.test.errors.push(new Array(error, asyncError));
       break;
     }
     case 'test_retry': {
-      event.test.errors = [];
+      event.test.errors = new Array();
       break;
     }
     case 'run_start': {

packages/jest-circus/src/run.ts

@@ -45,7 +45,7 @@ const _runTestsForDescribeBlock = async (describeBlock: DescribeBlock) => {
 
   // Tests that fail and are retried we run after other tests
   const retryTimes = parseInt(global[RETRY_TIMES], 10) || 0;
-  const deferredRetryTests = [];
+  const deferredRetryTests = new Array();
 
   for (const test of describeBlock.tests) {
     await _runTest(test);

packages/jest-circus/src/state.ts

@@ -29,7 +29,7 @@ const INITIAL_STATE: State = {
   rootDescribeBlock: ROOT_DESCRIBE_BLOCK,
   testNamePattern: null,
   testTimeout: 5000,
-  unhandledErrors: [],
+  unhandledErrors: new Array(),
 };
 
 global[STATE_SYM] = INITIAL_STATE;

packages/jest-circus/src/utils.ts

@@ -44,12 +44,12 @@ export const makeDescribe = (
   }
 
   return {
-    children: [],
-    hooks: [],
+    children: new Array(),
+    hooks: new Array(),
     mode: _mode,
     name: convertDescriptorToString(name),
     parent,
-    tests: [],
+    tests: new Array(),
   };
 };
 
@@ -63,7 +63,7 @@ export const makeTest = (
 ): TestEntry => ({
   asyncError,
   duration: null,
-  errors: [],
+  errors: new Array(),
   fn,
   invocations: 0,
   mode,
@@ -95,8 +95,8 @@ export const getAllHooksForDescribe = (describe: DescribeBlock) => {
     beforeAll: Array<Hook>;
     afterAll: Array<Hook>;
   } = {
-    afterAll: [],
-    beforeAll: [],
+    afterAll: new Array(),
+    beforeAll: new Array(),
   };
 
   if (hasEnabledTest(describe)) {
@@ -119,11 +119,11 @@ export const getEachHooksForTest = (test: TestEntry) => {
   const result: {
     beforeEach: Array<Hook>;
     afterEach: Array<Hook>;
-  } = {afterEach: [], beforeEach: []};
+  } = {afterEach: new Array(), beforeEach: new Array()};
   let block: DescribeBlock | undefined | null = test.parent;
 
   do {
-    const beforeEachForCurrentBlock = [];
+    const beforeEachForCurrentBlock = new Array();
     for (const hook of block.hooks) {
       switch (hook.type) {
         case 'beforeEach':
@@ -136,7 +136,10 @@ export const getEachHooksForTest = (test: TestEntry) => {
     }
     // 'beforeEach' hooks are executed from top to bottom, the opposite of the
     // way we traversed it.
-    result.beforeEach = [...beforeEachForCurrentBlock, ...result.beforeEach];
+    result.beforeEach = new Array(
+      ...beforeEachForCurrentBlock,
+      ...result.beforeEach,
+    );
   } while ((block = block.parent));
   return result;
 };
@@ -248,9 +251,9 @@ export const makeRunResult = (
 
 const makeTestResults = (describeBlock: DescribeBlock): TestResults => {
   const {includeTestLocationInResult} = getState();
-  let testResults: TestResults = [];
+  let testResults: TestResults = new Array();
   for (const test of describeBlock.tests) {
-    const testPath = [];
+    const testPath = new Array();
     let parent: TestEntry | DescribeBlock = test;
     do {
       testPath.unshift(parent.name);
@@ -298,7 +301,7 @@ const makeTestResults = (describeBlock: DescribeBlock): TestResults => {
 // Return a string that identifies the test (concat of parent describe block
 // names + test title)
 export const getTestID = (test: TestEntry) => {
-  const titles = [];
+  const titles = new Array();
   let parent: TestEntry | DescribeBlock = test;
   do {
     titles.unshift(parent.name);
@@ -342,7 +345,7 @@ export const addErrorToEachTestUnderDescribe = (
   asyncError: Exception,
 ) => {
   for (const test of describeBlock.tests) {
-    test.errors.push([error, asyncError]);
+    test.errors.push(new Array(error, asyncError));
   }
 
   for (const child of describeBlock.children) {

packages/jest-jasmine2/src/queueRunner.js

@@ -51,7 +51,9 @@ export default function queueRunner(options: Options) {
       }
     });
 
-    promise = Promise.race([promise, token]);
+    // `new Array` to avoid contaminated array prototypes
+    // $FlowFixMe
+    promise = Promise.race(new Array(promise, token));
 
     if (!timeout) {
       return promise;

packages/jest-util/src/installCommonGlobals.ts

@@ -46,6 +46,11 @@ export default function(
       value: fs.existsSync.bind(fs),
       writable: false,
     },
+    [symbol.for('jest-native-array')]: {
+      enumerable: false,
+      value: Array.bind(Array),
+      writable: false,
+    },
     'jest-symbol-do-not-touch': {
       enumerable: false,
       value: symbol,

scripts/babel-plugin-jest-native-globals.js

@@ -29,6 +29,9 @@ module.exports = ({template}) => {
   const fsExistsFileDeclaration = template(`
     var jestExistsFile = global[Symbol.for('jest-native-exists-file')] || fs.existsSync;
   `);
+  const arrayDeclaration = template(`
+    var Array = global[Symbol.for('jest-native-array')] || Array;
+  `);
 
   return {
     name: 'jest-native-globals',
@@ -116,6 +119,15 @@ module.exports = ({template}) => {
             path.parentPath.replaceWithSourceString('jestExistsFile');
           }
         }
+        if (path.node.name === 'Array' && !state.jestInjectedArray) {
+          state.jestInjectedArray = true;
+          path
+            .findParent(p => p.isProgram())
+            .unshiftContainer('body', arrayDeclaration());
+          path
+            .findParent(p => p.isProgram())
+            .unshiftContainer('body', symbolDeclaration());
+        }
       },
     },
   };