0
# ESLint Configuration
1

2
Pre-configured ESLint setup with React, TypeScript, and Jest support, plus legacy fabric configuration compatibility. The package provides comprehensive ESLint configurations optimized for modern JavaScript and TypeScript development.
3

4
## Capabilities
5

6
### Main ESLint Configuration
7

8
Modern ESLint configuration with React, TypeScript, and Jest support.
9

10
```typescript { .api }
11
// ESLint configuration object (CommonJS module.exports)
12
// Location: src/config/eslint/index.ts
13
const eslintConfig: {
14
  parser: string;
15
  plugins: string[];
16
  settings: {
17
    react: {
18
      version: string;
19
    };
20
  };
21
  env: {
22
    browser: boolean;
23
    node: boolean;
24
    es2022: boolean;
25
    jest: boolean;
26
  };
27
  rules: Record<string, any>;
28
  overrides: Array<{
29
    parser?: string;
30
    plugins?: string[];
31
    files: string[];
32
    rules: Record<string, any>;
33
    settings?: any;
34
    extends?: string[];
35
  }>;
36
  parserOptions: {
37
    ecmaFeatures: {
38
      jsx: boolean;
39
    };
40
    babelOptions: {
41
      babelrc: boolean;
42
      configFile: boolean;
43
      browserslistConfigFile: boolean;
44
      presets: string[];
45
    };
46
    requireConfigFile: boolean;
47
    warnOnUnsupportedTypeScriptVersion: boolean;
48
  };
49
};
50
```
51

52
**Key Features:**
53
- **Parser**: Babel ESLint parser for JavaScript/JSX
54
- **Plugins**: React and React Hooks plugins
55
- **Environment**: Browser, Node.js, ES2022, and Jest environments
56
- **TypeScript Override**: @typescript-eslint parser for .ts/.tsx files
57
- **Jest Override**: Jest plugin for test files
58
- **Babel Integration**: Uses @umijs/babel-preset-umi
59

60
**Usage:**
61

62
```javascript
63
// .eslintrc.js
64
module.exports = require("@umijs/lint/dist/config/eslint");
65
```
66

67
### Legacy ESLint Configuration
68

69
Legacy fabric-compatible ESLint configuration for backward compatibility.
70

71
```typescript { .api }
72
// Legacy ESLint configuration object (CommonJS module.exports)
73
// Location: src/config/eslint/legacy.ts
74
const eslintLegacyConfig: {
75
  extends: string[];
76
  parser: string;
77
  plugins: string[];
78
  env: {
79
    browser: boolean;
80
    node: boolean;
81
    es6: boolean;
82
    mocha: boolean;
83
    jest: boolean;
84
    jasmine: boolean;
85
  };
86
  rules: Record<string, any>;
87
  overrides: Array<{
88
    files: string[];
89
    parser: string;
90
    rules: Record<string, any>;
91
    extends: string[];
92
  }>;
93
  parserOptions: {
94
    ecmaFeatures: {
95
      jsx: boolean;
96
    };
97
    babelOptions: {
98
      babelrc: boolean;
99
      configFile: boolean;
100
      browserslistConfigFile: boolean;
101
      presets: string[];
102
    };
103
    requireConfigFile: boolean;
104
    warnOnUnsupportedTypeScriptVersion: boolean;
105
  };
106
};
107
```
108

109
**Key Features:**
110
- **Extends**: Prettier and React recommended configurations
111
- **Legacy Support**: Compatible with @umijs/fabric configurations
112
- **Test Frameworks**: Mocha, Jest, and Jasmine support
113
- **TypeScript**: @typescript-eslint recommended rules for TypeScript files
114

115
**Usage:**
116

117
```javascript
118
// .eslintrc.js for legacy projects
119
module.exports = require("@umijs/lint/dist/config/eslint/legacy");
120
```
121

122
### ESLint Setup Module
123

124
Module resolution patch for ESLint plugins.
125

126
```typescript { .api }
127
// ESLint plugin resolution patch
128
// Location: src/config/eslint/setup.ts
129
// Automatically patches ESLint plugin resolve logic using @rushstack/eslint-patch
130
```
131

132
**Purpose:**
133
- Resolves ESLint plugin loading issues in monorepos
134
- Applied automatically when ESLint configurations are loaded
135
- Uses @rushstack/eslint-patch for modern module resolution
136

137
### Rule Sets
138

139
#### Recommended Rules
140

141
Modern recommended rules for Umi.js projects.
142

143
```typescript { .api }
144
// Location: src/config/eslint/rules/recommended.ts
145
const recommendedRules: Record<string, number | any[]>;
146
const jestRules: Record<string, number | any[]>;
147
const typescriptRules: Record<string, number | any[]>;
148
```
149

150
**Rule Categories:**
151
- **Core ESLint**: Array callback return, eqeqeq, guard-for-in, no-eval, etc.
152
- **React**: JSX key, no duplicate props, hooks rules, etc.
153
- **Jest**: No focused tests, valid expect, no standalone expect, etc.
154
- **TypeScript**: Ban types, no unused vars, consistent type imports, etc.
155

156
#### Fabric Legacy Rules
157

158
Legacy rules from @umijs/fabric for backward compatibility.
159

160
```typescript { .api }
161
// Location: src/config/eslint/rules/fabric.ts
162
const fabricRules: Record<string, number | any[]>;
163
const fabricTypescriptRules: Record<string, number | any[]>;
164
```
165

166
**Rule Categories:**
167
- **Legacy ESLint**: Based on @umijs/fabric configuration
168
- **React**: Display name, prop types, self-closing components, etc.
169
- **TypeScript**: Array type, method signature style, typedef, etc.
170

171
## Configuration Examples
172

173
### Basic Project Setup
174

175
```javascript
176
// .eslintrc.js
177
module.exports = require("@umijs/lint/dist/config/eslint");
178
```
179

180
### TypeScript Project
181

182
```json
183
// .eslintrc.json
184
{
185
  "extends": ["@umijs/lint/dist/config/eslint"]
186
}
187
```
188

189
### Legacy Project Migration
190

191
```javascript
192
// .eslintrc.js
193
module.exports = require("@umijs/lint/dist/config/eslint/legacy");
194
```
195

196
### Custom Rule Overrides
197

198
```javascript
199
// .eslintrc.js
200
const baseConfig = require("@umijs/lint/dist/config/eslint");
201

202
module.exports = {
203
  ...baseConfig,
204
  rules: {
205
    ...baseConfig.rules,
206
    "no-console": "warn",
207
    "react/prop-types": "off"
208
  }
209
};
210
```
211

212
## File Pattern Matching
213

214
### TypeScript Override
215
- **Files**: `**/*.{ts,tsx}`
216
- **Parser**: @typescript-eslint/parser
217
- **Rules**: TypeScript-specific rules applied
218

219
### Jest Override
220
- **Files**: `**/*.{test,spec,unit,e2e}.{ts,tsx,js,jsx}`
221
- **Plugin**: Jest plugin enabled
222
- **Rules**: Jest-specific rules applied
223
- **Settings**: Automatic Jest version detection
224

225
## Jest Version Detection
226

227
```typescript { .api }
228
/**
229
 * Automatically detects Jest version for optimal rule configuration
230
 * Falls back to version 29 if Jest is not found
231
 * @returns Jest version number
232
 */
233
function detectJestVersion(): number;
234
```
235

236
**Behavior:**
237
- Attempts to resolve `jest/package.json` from current working directory
238
- Extracts version from package.json
239
- Returns 29 as fallback if Jest is not installed
240
- Used for Jest plugin configuration in test file overrides
241

242
## Rule Severity Levels
243

244
- **0 or "off"**: Rule is disabled
245
- **1 or "warn"**: Rule generates warnings
246
- **2 or "error"**: Rule generates errors (fails linting)
247

248
## Built-in Plugins
249

250
### React Plugin
251
- JSX syntax support
252
- React-specific rules and best practices
253
- Automatic React version detection
254

255
### React Hooks Plugin  
256
- Rules of Hooks enforcement
257
- Exhaustive dependencies checking
258

259
### TypeScript Plugin
260
- Type-aware linting rules
261
- TypeScript syntax support
262
- Import/export validation
263

264
### Jest Plugin
265
- Test-specific linting rules
266
- Jest API validation
267
- Test structure enforcement