WIP

Author: jeysal

e2e/babel-plugin-jest-hoist/__tests__/importJest.test.js

@@ -7,12 +7,19 @@
  */
 
 import {jest} from '@jest/globals';
+import * as JestGlobals from '@jest/globals';
 
 // The virtual mock call below will be hoisted above this `require` call.
 const virtualModule = require('virtual-module');
+const virtualModule2 = require('virtual-module-2');
 
 jest.mock('virtual-module', () => 'kiwi', {virtual: true});
+JestGlobals.jest.mock('virtual-module', () => 'banana', {virtual: true});
 
-test('works with virtual modules', () => {
+test('named import', () => {
   expect(virtualModule).toBe('kiwi');
 });
+
+test('namespace import', () => {
+  expect(virtualModule2).toBe('banana');
+});

e2e/babel-plugin-jest-hoist/__tests__/integration.test.js

@@ -6,6 +6,9 @@
  *
  */
 
+// TODO deep in blocks not hoisted
+// TODO shadowed not hoisted
+
 'use strict';
 
 import React from 'react';

packages/babel-plugin-jest-hoist/package.json

@@ -20,10 +20,12 @@
     }
   },
   "dependencies": {
-    "@types/babel__traverse": "^7.0.6"
+    "@types/babel__traverse": "^7.0.6",
+    "lodash.sortby": "^4.7.0"
   },
   "devDependencies": {
     "@babel/types": "^7.3.3",
+    "@types/lodash.sortby": "^4.7.6",
     "@types/node": "*"
   },
   "publishConfig": {

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

@@ -7,7 +7,13 @@
  */
 
 import type {NodePath, Visitor} from '@babel/traverse';
-import type {Identifier} from '@babel/types';
+import {
+  Identifier,
+  Node,
+  Expression,
+  isImportDeclaration,
+} from '@babel/types';
+import sortBy = require('lodash.sortby');
 
 // We allow `jest`, `expect`, `require`, all default Node.js globals and all
 // ES2015 built-ins to be used inside of a `jest.mock` factory.
@@ -70,7 +76,10 @@ const WHITELISTED_IDENTIFIERS = new Set<string>(
   ].sort(),
 );
 
-const JEST_GLOBAL = {name: 'jest'};
+const JEST_GLOBAL_NAME = 'jest';
+const JEST_GLOBALS_MODULE_NAME = '@jest/globals';
+const JEST_GLOBALS_MODULE_JEST_EXPORT_NAME = 'jest';
+
 // TODO: Should be Visitor<{ids: Set<NodePath<Identifier>>}>, but `ReferencedIdentifier` doesn't exist
 const IDVisitor = {
   ReferencedIdentifier(path: NodePath<Identifier>) {
@@ -82,7 +91,7 @@ const IDVisitor = {
 
 const FUNCTIONS: Record<
   string,
-  (args: Array<NodePath>) => boolean
+  <T extends Node>(args: Array<NodePath<T>>) => boolean
 > = Object.create(null);
 
 FUNCTIONS.mock = args => {
@@ -152,72 +161,95 @@ FUNCTIONS.deepUnmock = args => args.length === 1 && args[0].isStringLiteral();
 FUNCTIONS.disableAutomock = FUNCTIONS.enableAutomock = args =>
   args.length === 0;
 
-export default (): {visitor: Visitor} => {
-  const shouldHoistExpression = (expr: NodePath): boolean => {
-    if (!expr.isCallExpression()) {
-      return false;
-    }
+const isIdentifierJestObject = (identifier: NodePath<Identifier>): boolean => {
+  // global
+  if (
+    identifier.node.name === JEST_GLOBAL_NAME &&
+    !identifier.scope.hasBinding(JEST_GLOBAL_NAME)
+  ) {
+    return true;
+  }
+  // import from '@jest/globals'
+  if (
+    identifier.referencesImport(
+      JEST_GLOBALS_MODULE_NAME,
+      JEST_GLOBALS_MODULE_JEST_EXPORT_NAME,
+    )
+  ) {
+    return true;
+  }
 
-    // TODO: avoid type casts - the types can be arrays (is it possible to ignore that without casting?)
-    const callee = expr.get('callee') as NodePath;
-    const expressionArguments = expr.get('arguments');
-    const object = callee.get('object') as NodePath;
-    const property = callee.get('property') as NodePath;
-    return (
-      property.isIdentifier() &&
-      FUNCTIONS[property.node.name] &&
-      (object.isIdentifier(JEST_GLOBAL) ||
-        (callee.isMemberExpression() && shouldHoistExpression(object))) &&
-      FUNCTIONS[property.node.name](
-        Array.isArray(expressionArguments)
-          ? expressionArguments
-          : [expressionArguments],
-      )
-    );
-  };
+  return false;
+};
 
-  const visitor: Visitor = {
-    ExpressionStatement(path) {
-      if (shouldHoistExpression(path.get('expression') as NodePath)) {
-        // @ts-ignore: private, magical property
-        path.node._blockHoist = Infinity;
-      }
-    },
-    ImportDeclaration(path) {
-      if (path.node.source.value === '@jest/globals') {
-        // @ts-ignore: private, magical property
-        path.node._blockHoist = Infinity;
-      }
-    },
-    VariableDeclaration(path) {
-      const declarations = path.get('declarations');
+const shouldHoistExpression = <T extends Node>(expr: NodePath<T>): boolean => {
+  if (!expr.isCallExpression()) {
+    return false;
+  }
+
+  const callee = expr.get<'callee'>('callee');
+  const args = expr.get<'arguments'>('arguments');
 
-      if (declarations.length === 1) {
-        const declarationInit = declarations[0].get('init');
+  if (!callee.isMemberExpression()) {
+    return false;
+  }
+
+  const object = callee.get<'object'>('object');
+  const property = callee.get<'property'>('property') as
+    | NodePath<Expression>
+    | NodePath<Identifier>;
 
-        if (declarationInit.isCallExpression()) {
-          const callee = declarationInit.get('callee') as NodePath;
-          const callArguments = declarationInit.get('arguments') as Array<
-            NodePath
-          >;
+  if (!property.isIdentifier()) {
+    return false;
+  }
+  const propertyName = property.node.name;
+
+  const objectIsJest =
+    (object.isIdentifier() && isIdentifierJestObject(object)) ||
+    // The Jest object could be returned from another call since the functions are all chainable.
+    shouldHoistExpression(object);
+  if (!objectIsJest) {
+    return false;
+  }
+
+  // Important: Call the function check last
+  // It might throw an error to display to the user,
+  // which should only happen if we're already sure it's a call on the Jest object.
+  const functionLooksHoistable =
+    FUNCTIONS[propertyName] && FUNCTIONS[propertyName](args);
+
+  return functionLooksHoistable;
+};
+
+// TODO `require`s
+export default (): {visitor: Visitor} => {
+  const visitor: Visitor = {
+    Program: {
+      enter(path) {
+        path.node.body = sortBy(path.node.body, node => {
+          console.log(require('@babel/generator').default(node));
 
           if (
-            callee.isIdentifier() &&
-            callee.node.name === 'require' &&
-            callArguments.length === 1
+            isImportDeclaration(node) &&
+            node.source.value === JEST_GLOBALS_MODULE_NAME
           ) {
-            const [argument] = callArguments;
-
-            if (
-              argument.isStringLiteral() &&
-              argument.node.value === '@jest/globals'
-            ) {
-              // @ts-ignore: private, magical property
-              path.node._blockHoist = Infinity;
-            }
+            console.log('found import');
+            return 0;
           }
-        }
-      }
+          const nodePath = path.get('body').find(p => p.node === node);
+          if (
+            nodePath &&
+            nodePath.isExpressionStatement() &&
+            shouldHoistExpression(nodePath.get<'expression'>('expression'))
+          ) {
+            console.log('found stmt');
+            return 1;
+          }
+
+          console.log('nope');
+          return 2;
+        });
+      },
     },
   };
 

yarn.lock

@@ -2382,6 +2382,18 @@
   resolved "https://registry.yarnpkg.com/@types/lockfile/-/lockfile-1.0.1.tgz#434a3455e89843312f01976e010c60f1bcbd56f7"
   integrity sha512-65WZedEm4AnOsBDdsapJJG42MhROu3n4aSSiu87JXF/pSdlubxZxp3S1yz3kTfkJ2KBPud4CpjoHVAptOm9Zmw==
 
+"@types/lodash.sortby@^4.7.6":
+  version "4.7.6"
+  resolved "https://registry.yarnpkg.com/@types/lodash.sortby/-/lodash.sortby-4.7.6.tgz#eed689835f274b553db4ae16a4a23f58b79618a1"
+  integrity sha512-EnvAOmKvEg7gdYpYrS6+fVFPw5dL9rBnJi3vcKI7wqWQcLJVF/KRXK9dH29HjGNVvFUj0s9prRP3J8jEGnGKDw==
+  dependencies:
+    "@types/lodash" "*"
+
+"@types/lodash@*":
+  version "4.14.149"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.149.tgz#1342d63d948c6062838fbf961012f74d4e638440"
+  integrity sha512-ijGqzZt/b7BfzcK9vTrS6MFljQRPn5BFWOx8oE0GYxribu6uV+aA9zZuXI1zc/etK9E8nrgdoF2+LgUw7+9tJQ==
+
 "@types/lolex@^5.1.0":
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/@types/lolex/-/lolex-5.1.0.tgz#11b4c4756c007306d0feeaf2f08f88350c635d2b"