feat: prefer importing jest globals [new rule]

- Fix jest-community#1101

Issue: jest-community#1101

Author: MadeinFrance

README.md

@@ -248,6 +248,7 @@ set to warn in.\
 | [prefer-expect-resolves](docs/rules/prefer-expect-resolves.md)               | Prefer `await expect(...).resolves` over `expect(await ...)` syntax       |     |     | 🔧  |     |     |
 | [prefer-hooks-in-order](docs/rules/prefer-hooks-in-order.md)                 | Prefer having hooks in a consistent order                                 |     |     |     |     |     |
 | [prefer-hooks-on-top](docs/rules/prefer-hooks-on-top.md)                     | Suggest having hooks before any test cases                                |     |     |     |     |     |
+| [prefer-importing-jest-globals](docs/rules/prefer-importing-jest-globals.md) | Prefer importing Jest globals                                             |     |     | 🔧  |     |     |
 | [prefer-lowercase-title](docs/rules/prefer-lowercase-title.md)               | Enforce lowercase test names                                              |     |     | 🔧  |     |     |
 | [prefer-mock-promise-shorthand](docs/rules/prefer-mock-promise-shorthand.md) | Prefer mock resolved/rejected shorthands for promises                     |     |     | 🔧  |     |     |
 | [prefer-snapshot-hint](docs/rules/prefer-snapshot-hint.md)                   | Prefer including a hint with external snapshots                           |     |     |     |     |     |

docs/rules/prefer-importing-jest-globals.md

@@ -0,0 +1,47 @@
+# Prefer importing Jest globals (`prefer-importing-jest-globals`)
+
+🔧 This rule is automatically fixable by the
+[`--fix` CLI option](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix).
+
+<!-- end auto-generated rule header -->
+
+This rule aims to enforce explicit imports from `@jest/globals`.
+
+1. This is useful for ensuring that the Jest APIs are imported the same way in
+   the codebase.
+2. When you can't modify Jest's
+   [`injectGlobals`](https://jestjs.io/docs/configuration#injectglobals-boolean)
+   configuration property, this rule can help to ensure that the Jest globals
+   are imported explicitly and facilitate a migration to `@jest/globals`.
+
+## Rule details
+
+Examples of **incorrect** code for this rule
+
+```js
+/* eslint jest/prefer-importing-jest-globals: "error" */
+
+describe('foo', () => {
+  it('accepts this input', () => {
+    // ...
+  });
+});
+```
+
+Examples of **correct** code for this rule
+
+```js
+/* eslint jest/prefer-importing-jest-globals: "error" */
+
+import { describe, it } from '@jest/globals';
+
+describe('foo', () => {
+  it('accepts this input', () => {
+    // ...
+  });
+});
+```
+
+## Further Reading
+
+- [Documentation](https://jestjs.io/docs/api)

src/__tests__/__snapshots__/rules.test.ts.snap

@@ -45,6 +45,7 @@ exports[`rules should export configs that refer to actual rules 1`] = `
       "jest/prefer-expect-resolves": "error",
       "jest/prefer-hooks-in-order": "error",
       "jest/prefer-hooks-on-top": "error",
+      "jest/prefer-importing-jest-globals": "error",
       "jest/prefer-lowercase-title": "error",
       "jest/prefer-mock-promise-shorthand": "error",
       "jest/prefer-snapshot-hint": "error",

src/__tests__/rules.test.ts

@@ -2,7 +2,7 @@ import { existsSync } from 'fs';
 import { resolve } from 'path';
 import plugin from '../';
 
-const numberOfRules = 53;
+const numberOfRules = 54;
 const ruleNames = Object.keys(plugin.rules);
 const deprecatedRules = Object.entries(plugin.rules)
   .filter(([, rule]) => rule.meta.deprecated)

src/rules/__tests__/prefer-importing-jest-globals.test.ts

@@ -0,0 +1,64 @@
+import { TSESLint } from '@typescript-eslint/utils';
+import dedent from 'dedent';
+import rule from '../prefer-importing-jest-globals';
+import { espreeParser } from './test-utils';
+
+const ruleTester = new TSESLint.RuleTester({
+  parser: espreeParser,
+  parserOptions: {
+    ecmaVersion: 2015,
+    sourceType: 'module',
+  },
+});
+
+ruleTester.run('prefer-importing-jest-globals', rule, {
+  valid: [
+    {
+      code: dedent`
+        import { test, expect } from '@jest/globals';
+
+        test('should pass', () => {
+            expect(true).toBeDefined();
+        });
+        `,
+      parserOptions: { sourceType: 'module' },
+    },
+    {
+      code: dedent`
+        import { it as itChecks } from '@jest/globals';
+
+        itChecks("foo");
+      `,
+      parserOptions: { sourceType: 'module' },
+    },
+    {
+      code: dedent`
+        const { test } = require('@jest/globals');
+
+        test("foo");
+      `,
+      parserOptions: { sourceType: 'module' },
+    },
+  ],
+  invalid: [
+    {
+      code: dedent`
+        describe("suite", () => { 
+          test("foo"); 
+          expect(true).toBeDefined();
+        })
+      `,
+      output: dedent`
+        import { describe, test, expect } from '@jest/globals';
+        describe("suite", () => { 
+          test("foo"); 
+          expect(true).toBeDefined();
+        })
+    `,
+      parserOptions: { sourceType: 'module' },
+      errors: [
+        { endColumn: 3, column: 1, messageId: 'preferImportingJestGlobal' },
+      ],
+    },
+  ],
+});

src/rules/prefer-importing-jest-globals.ts

@@ -0,0 +1,69 @@
+import globalsJson from '../globals.json';
+import { createRule, parseJestFnCall } from './utils';
+
+export default createRule({
+  name: __filename,
+  meta: {
+    docs: {
+      category: 'Best Practices',
+      description: 'Prefer importing Jest globals',
+      recommended: false,
+    },
+    messages: {
+      preferImportingJestGlobal: `Import the following Jest functions from '@jest/globals': {{ jestFunctions }}`,
+    },
+    fixable: 'code',
+    type: 'problem',
+    schema: [],
+  },
+  defaultOptions: [],
+  create(context) {
+    const jestGlobalFunctions = Object.keys(globalsJson);
+    const importedJestFunctions: string[] = [];
+    const usedJestFunctions = new Set<string>();
+
+    return {
+      CallExpression(node) {
+        const jestFnCall = parseJestFnCall(node, context);
+
+        if (!jestFnCall) {
+          return;
+        }
+        if (
+          jestFnCall.head.type === 'import' &&
+          jestGlobalFunctions.includes(jestFnCall.name)
+        ) {
+          importedJestFunctions.push(jestFnCall.name);
+        }
+
+        /* istanbul ignore else */
+        if (jestGlobalFunctions.includes(jestFnCall.name)) {
+          usedJestFunctions.add(jestFnCall.name);
+        }
+      },
+      'Program:exit'() {
+        const jestFunctionsToImport = Array.from(usedJestFunctions).filter(
+          jestFunction => !importedJestFunctions.includes(jestFunction),
+        );
+
+        if (jestFunctionsToImport.length > 0) {
+          const node = context.getSourceCode().ast;
+          const jestFunctionsToImportFormatted =
+            jestFunctionsToImport.join(', ');
+
+          context.report({
+            node,
+            messageId: 'preferImportingJestGlobal',
+            data: { jestFunctions: jestFunctionsToImportFormatted },
+            fix(fixer) {
+              return fixer.insertTextBefore(
+                node,
+                `import { ${jestFunctionsToImportFormatted} } from '@jest/globals';\n`,
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+});