feat(wip): add no-hooks rule

Resolves jest-community#72

README.md

@@ -83,6 +83,7 @@ for more information about extending configuration files.
 | [consistent-test-it](docs/rules/consistent-test-it.md)             | Enforce consistent test or it keyword                           |                                                                         | ![fixable](https://img.shields.io/badge/-fixable-green.svg) |
 | [no-disabled-tests](docs/rules/no-disabled-tests.md)               | Disallow disabled tests                                         | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
 | [no-focused-tests](docs/rules/no-focused-tests.md)                 | Disallow focused tests                                          | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
+| [no-hooks](docs/rules/no-hooks.md)                                 | Disallow setup and teardown hooks                               |                                                                         |                                                             |
 | [no-identical-title](docs/rules/no-identical-title.md)             | Disallow identical titles                                       | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
 | [no-large-snapshots](docs/rules/no-large-snapshots.md)             | Disallow large snapshots                                        |                                                                         |                                                             |
 | [prefer-to-have-length](docs/rules/prefer-to-have-length.md)       | Suggest using `toHaveLength()`                                  | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) | ![fixable](https://img.shields.io/badge/-fixable-green.svg) |

docs/rules/no-hooks.md

@@ -0,0 +1,14 @@
+# Disallow setup and teardown hooks (no-hooks)
+
+## Rule Details
+
+## Options
+
+### `allowed`
+
+## When Not To Use It
+
+## Further Reading
+
+* [Jest docs - Setup and Teardown](https://facebook.github.io/jest/docs/en/setup-teardown.html)
+* [@jamiebuilds Twitter thread](https://twitter.com/jamiebuilds/status/954906997169664000)

index.js

@@ -3,6 +3,7 @@
 const consistentTestIt = require('./rules/consistent-test-it');
 const noDisabledTests = require('./rules/no-disabled-tests');
 const noFocusedTests = require('./rules/no-focused-tests');
+const noHooks = require('./rules/no-hooks');
 const noIdenticalTitle = require('./rules/no-identical-title');
 const noLargeSnapshots = require('./rules/no-large-snapshots');
 const preferToBeNull = require('./rules/prefer-to-be-null');
@@ -61,6 +62,7 @@ module.exports = {
     'consistent-test-it': consistentTestIt,
     'no-disabled-tests': noDisabledTests,
     'no-focused-tests': noFocusedTests,
+    'no-hooks': noHooks,
     'no-identical-title': noIdenticalTitle,
     'no-large-snapshots': noLargeSnapshots,
     'prefer-to-be-null': preferToBeNull,

rules/__tests__/no-hooks.test.js

@@ -0,0 +1,49 @@
+'use strict';
+
+const RuleTester = require('eslint').RuleTester;
+const rules = require('../..').rules;
+const ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 6,
+  },
+});
+
+const error = {
+  ruleId: 'no-hooks',
+  message: 'Unexpected setup/teardown hook',
+};
+
+ruleTester.run('no-hooks', rules['no-hooks'], {
+  valid: [
+    'test("foo")',
+    'describe("foo", () => { it("bar") })',
+    'test("foo", () => { expect(subject.beforeEach()).toBe(true) })',
+    {
+      code: 'afterEach(() => {}); afterAll(() => {});',
+      options: [{ allowed: ['afterEach', 'afterAll'] }],
+    },
+  ],
+  invalid: [
+    {
+      code: 'beforeAll(() => {})',
+      errors: [error],
+    },
+    {
+      code: 'beforeEach(() => {})',
+      errors: [error],
+    },
+    {
+      code: 'afterAll(() => {})',
+      errors: [error],
+    },
+    {
+      code: 'afterEach(() => {})',
+      errors: [error],
+    },
+    {
+      code: 'beforeEach(() => {}); afterEach(() => { jest.resetModules() });',
+      options: [{ allowed: ['afterEach'] }],
+      errors: [error],
+    },
+  ],
+});

rules/no-hooks.js

@@ -0,0 +1,52 @@
+'use strict';
+
+module.exports = {
+  meta: {
+    docs: {
+      url:
+        'https://github.com/jest-community/eslint-plugin-jest/blob/master/docs/rules/no-hooks.md',
+    },
+  },
+  schema: [
+    {
+      type: 'object',
+      properties: {
+        allowed: {
+          type: 'array',
+          contains: ['beforeAll', 'beforeEach', 'afterAll', 'afterEach'],
+        },
+      },
+      additionalProperties: false,
+    },
+  ],
+  create(context) {
+    const testHookNames = Object.assign(Object.create(null), {
+      beforeAll: true,
+      beforeEach: true,
+      afterAll: true,
+      afterEach: true,
+    });
+
+    const allowed = (context.options[0] || { allowed: [] }).allowed.reduce(
+      (hashMap, value) => {
+        hashMap[value] = true;
+        return hashMap;
+      },
+      Object.create(null)
+    );
+
+    const isHook = node => testHookNames[node.callee.name];
+    const isWhitelisted = node => allowed[node.callee.name];
+
+    return {
+      CallExpression(node) {
+        if (isHook(node) && !isWhitelisted(node)) {
+          context.report({
+            node,
+            message: 'Unexpected setup/teardown hook',
+          });
+        }
+      },
+    };
+  },
+};