feat(rules): prefer-valid-title (#273)

docs/rules/valid-title.md

@@ -0,0 +1,65 @@
+# Disallow duplicate setup and teardown hooks (no-duplicate-hooks)
+
+A describe/ test block should not contain accidentalSpace or duplicatePrefix.
+
+## Rule Details
+
+**duplicatePrefix**
+
+A describe/ test block should not start with duplicatePrefix
+
+Examples of **incorrect** code for this rule
+
+```js
+test('test foo', () => {});
+it('it foo', () => {});
+
+describe('foo', () => {
+  test('test bar', () => {});
+});
+
+describe('describe foo', () => {
+  test('bar', () => {});
+});
+```
+
+Examples of **correct** code for this rule
+
+```js
+test('foo', () => {});
+it('foo', () => {});
+
+describe('foo', () => {
+  test('bar', () => {});
+});
+```
+
+**accidentalSpace**
+
+A describe/ test block should not contain accidentalSpace
+
+Examples of **incorrect** code for this rule
+
+```js
+test(' foo', () => {});
+it(' foo', () => {});
+
+describe('foo', () => {
+  test(' bar', () => {});
+});
+
+describe(' foo', () => {
+  test('bar', () => {});
+});
+```
+
+Examples of **correct** code for this rule
+
+```js
+test('foo', () => {});
+it('foo', () => {});
+
+describe('foo', () => {
+  test('bar', () => {});
+});
+```

src/__tests__/rules.test.ts

@@ -3,7 +3,7 @@ import { resolve } from 'path';
 import plugin from '../';
 
 const ruleNames = Object.keys(plugin.rules);
-const numberOfRules = 40;
+const numberOfRules = 41;
 
 describe('rules', () => {
   it('should have a corresponding doc for each rule', () => {

src/rules/__tests__/valid-title.test.ts

@@ -0,0 +1,161 @@
+import { TSESLint } from '@typescript-eslint/experimental-utils';
+import rule from '../valid-title';
+
+const ruleTester = new TSESLint.RuleTester({
+  parserOptions: {
+    ecmaVersion: 8,
+  },
+});
+
+ruleTester.run('no-accidental-space', rule, {
+  valid: [
+    'describe("foo", function () {})',
+    'describe(6, function () {})',
+    'fdescribe("foo", function () {})',
+    'xdescribe("foo", function () {})',
+    'it("foo", function () {})',
+    'fit("foo", function () {})',
+    'xit("foo", function () {})',
+    'test("foo", function () {})',
+    'xtest("foo", function () {})',
+    'someFn("foo", function () {})',
+    `
+    describe('foo', () => {
+      it('bar', () => {})
+    })
+    `,
+  ],
+  invalid: [
+    {
+      code: 'describe(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'fdescribe(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'xdescribe(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'it(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'fit(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'xit(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'test(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: 'xtest(" foo", function () {})',
+      errors: [{ messageId: 'accidentalSpace', column: 1, line: 1 }],
+    },
+    {
+      code: `
+      describe(' foo', () => {
+        it('bar', () => {})
+      })
+      `,
+      errors: [{ messageId: 'accidentalSpace', column: 7, line: 2 }],
+    },
+    {
+      code: `
+      describe('foo', () => {
+        it(' bar', () => {})
+      })
+      `,
+      errors: [{ messageId: 'accidentalSpace', column: 9, line: 3 }],
+    },
+  ],
+});
+
+ruleTester.run('no-duplicate-prefix ft describe', rule, {
+  valid: [
+    'describe("foo", function () {})',
+    'fdescribe("foo", function () {})',
+    'xdescribe("foo", function () {})',
+  ],
+  invalid: [
+    {
+      code: 'describe("describe foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+    {
+      code: 'fdescribe("describe foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+    {
+      code: 'xdescribe("describe foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+  ],
+});
+
+ruleTester.run('no-duplicate-prefix ft test', rule, {
+  valid: ['test("foo", function () {})', 'xtest("foo", function () {})'],
+  invalid: [
+    {
+      code: 'test("test foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+    {
+      code: 'xtest("test foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+  ],
+});
+
+ruleTester.run('no-duplicate-prefix ft it', rule, {
+  valid: [
+    'it("foo", function () {})',
+    'fit("foo", function () {})',
+    'xit("foo", function () {})',
+  ],
+  invalid: [
+    {
+      code: 'it("it foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+    {
+      code: 'fit("it foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+    {
+      code: 'xit("it foo", function () {})',
+      errors: [{ messageId: 'duplicatePrefix', column: 1, line: 1 }],
+    },
+  ],
+});
+
+ruleTester.run('no-duplicate-prefix ft nested', rule, {
+  valid: [
+    `
+      describe('foo', () => {
+        it('bar', () => {})
+      })`,
+  ],
+  invalid: [
+    {
+      code: `
+      describe('describe foo', () => {
+        it('bar', () => {})
+      })`,
+      errors: [{ messageId: 'duplicatePrefix', column: 7, line: 2 }],
+    },
+    {
+      code: `
+      describe('foo', () => {
+        it('it bar', () => {})
+      })`,
+      errors: [{ messageId: 'duplicatePrefix', column: 9, line: 3 }],
+    },
+  ],
+});

src/rules/valid-title.ts

@@ -0,0 +1,64 @@
+import {
+  createRule,
+  getNodeName,
+  getStringValue,
+  isDescribe,
+  isStringNode,
+  isTestCase,
+} from './utils';
+
+import { TSESTree } from '@typescript-eslint/experimental-utils';
+
+const trimFXprefix = (word: string) =>
+  ['f', 'x'].includes(word.charAt(0)) ? word.substr(1) : word;
+
+const getNodeTitle = (node: TSESTree.CallExpression): string | null => {
+  const [argument] = node.arguments;
+
+  return isStringNode(argument) ? getStringValue(argument) : null;
+};
+
+export default createRule({
+  name: __filename,
+  meta: {
+    docs: {
+      category: 'Best Practices',
+      description: 'Enforce valid titles',
+      recommended: false,
+    },
+    messages: {
+      duplicatePrefix: 'should not have duplicate prefix',
+      accidentalSpace: 'should not have space in the beginning',
+    },
+    type: 'suggestion',
+    schema: [],
+  },
+  defaultOptions: [],
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (!isDescribe(node) && !isTestCase(node)) return;
+
+        const title = getNodeTitle(node);
+        if (!title) return;
+
+        if (title.trimLeft().length !== title.length) {
+          context.report({
+            messageId: 'accidentalSpace',
+            node,
+          });
+        }
+
+        const nodeName = trimFXprefix(getNodeName(node.callee));
+        const [firstWord] = title.split(' ');
+
+        if (firstWord.toLowerCase() === nodeName) {
+          context.report({
+            messageId: 'duplicatePrefix',
+            node,
+          });
+        }
+      },
+    };
+  },
+});