Add eslint, prettier, env to the application.

It’s a pity that Angular, by default, does not generate all this itself. Changing schematics can improve the quality of several thousand Angular projects.

Setting up eslint 9

Connect eslint:

yarn ng add @angular-eslint/schematics

Three packages have been added to package.json:

{
  "devDependencies": {
       …,      
       "angular-eslint": "18.0.1",
       "eslint": "^9.3.0",
       "typescript-eslint": "8.0.0-alpha.20" 
   }
}

And in target in angular.json:

{
  "projects": {
    "buy-and-fly": {
      "architect": {
        …,
        "lint": {
          "builder": "@angular-eslint/builder:lint",
          "options": {
            "lintFilePatterns": [
              "src/**/*.ts",
              "src/**/*.html"
            ]
          }
        }
      }
    }
  },
  "cli": {
    "schematicCollections": [
      "@angular-eslint/schematics"
    ]
  }
}

The eslint.config.js file was also created:

// @ts-check
const eslint = require("@eslint/js");
const tseslint = require("typescript-eslint");
const angular = require("angular-eslint");

module.exports = tseslint.config(
  {
    files: ["**/*.ts"],
    extends: [
      eslint.configs.recommended,
      ...tseslint.configs.recommended,
      ...tseslint.configs.stylistic,
      ...angular.configs.tsRecommended,
    ],
    processor: angular.processInlineTemplates,
    rules: {
      "@angular-eslint/directive-selector": [
        "error",
        {
          type: "attribute",
          prefix: "app",
          style: "camelCase",
        },
      ],
      "@angular-eslint/component-selector": [
        "error",
        {
          type: "element",
          prefix: "app",
          style: "kebab-case",
        },
      ],
    },
  },
  {
    files: ["**/*.html"],
    extends: [
      ...angular.configs.templateRecommended,
      ...angular.configs.templateAccessibility,
    ],
    rules: {},
  }
);

Basic linters are good, but you can make them better!

Add a plugin:

yarn add -D eslint-plugin-simple-import-sort

Let's include several rules:

// @ts-check
const eslint = require('@eslint/js');
const tseslint = require('typescript-eslint');
const angular = require('angular-eslint');
const simpleImportSort = require('eslint-plugin-simple-import-sort');

module.exports = tseslint.config(
  {
    files: ['**/*.ts'],
    extends: [
      eslint.configs.recommended,
      ...tseslint.configs.recommended,
      ...tseslint.configs.stylistic,
      ...angular.configs.tsRecommended,
      {
        plugins: {
          'simple-import-sort': simpleImportSort,
        },
        rules: {
          'simple-import-sort/imports': [
            'error',
            {
              groups: [['^\\u0000'], ['^@?(?!baf)\\w'], ['^@baf?\\w'], ['^\\w'], ['^[^.]'], ['^\\.']],
            },
          ],
          'simple-import-sort/exports': 'error',
        },
      },
    ],
    processor: angular.processInlineTemplates,
    rules: {
      '@angular-eslint/directive-selector': [
        'error',
        {
          type: 'attribute',
          prefix: 'baf',
          style: 'camelCase',
        },
      ],
      '@angular-eslint/component-selector': [
        'error',
        {
          type: 'element',
          prefix: 'baf',
          style: 'kebab-case',
        },
      ],
      '@typescript-eslint/naming-convention': [
        'error',
        {
          selector: 'default',
          format: ['camelCase'],
          leadingUnderscore: 'allow',
          trailingUnderscore: 'allow',
          filter: {
            regex: '^(ts-jest|\\^.*)$',
            match: false,
          },
        },
        {
          selector: 'default',
          format: ['camelCase'],
          leadingUnderscore: 'allow',
          trailingUnderscore: 'allow',
        },
        {
          selector: 'variable',
          format: ['camelCase', 'UPPER_CASE'],
          leadingUnderscore: 'allow',
          trailingUnderscore: 'allow',
        },
        {
          selector: 'typeLike',
          format: ['PascalCase'],
        },
        {
          selector: 'enumMember',
          format: ['PascalCase'],
        },
        {
          selector: 'property',
          format: null,
          filter: {
            regex: '^(host)$',
            match: false,
          },
        },
      ],
      complexity: 'error',
      'max-len': [
        'error',
        {
          code: 140,
        },
      ],
      'no-new-wrappers': 'error',
      'no-throw-literal': 'error',
      '@typescript-eslint/consistent-type-definitions': 'error',
      'no-shadow': 'off',
      '@typescript-eslint/no-shadow': 'error',
      'no-invalid-this': 'off',
      '@typescript-eslint/no-invalid-this': ['warn'],
      '@angular-eslint/no-host-metadata-property': 'off',
    },
  },
  {
    files: ['**/*.html'],
    extends: [...angular.configs.templateRecommended, ...angular.configs.templateAccessibility],
    rules: {},
  },
)

'], ['^\\.']], }, ], 'simple-import-sort/exports': 'error', }, }, ], processor: angular.processInlineTemplates, rules: { '@angular-eslint/directive-selector': [ 'error', { type: 'attribute', prefix: 'baf', style: 'camelCase', }, ], '@angular-eslint/component-selector': [ 'error', { type: 'element', prefix: 'baf', style: 'kebab-case', }, ], '@typescript-eslint/naming-convention': [ 'error', { selector: 'default', format: ['camelCase'], leadingUnderscore: 'allow', trailingUnderscore: 'allow', filter: { regex: '^(ts-jest|\\^.*)$', match: false, }, }, { selector: 'default', format: ['camelCase'], leadingUnderscore: 'allow', trailingUnderscore: 'allow', }, { selector: 'variable', format: ['camelCase', 'UPPER_CASE'], leadingUnderscore: 'allow', trailingUnderscore: 'allow', }, { selector: 'typeLike', format: ['PascalCase'], }, { selector: 'enumMember', format: ['PascalCase'], }, { selector: 'property', format: null, filter: { regex: '^(host)$', match: false, }, }, ], complexity: 'error', 'max-len': [ 'error', { code: 140, }, ], 'no-new-wrappers': 'error', 'no-throw-literal': 'error', '@typescript-eslint/consistent-type-definitions': 'error', 'no-shadow': 'off', '@typescript-eslint/no-shadow': 'error', 'no-invalid-this': 'off', '@typescript-eslint/no-invalid-this': ['warn'], '@angular-eslint/no-host-metadata-property': 'off', }, }, { files: ['**/*.html'], extends: [...angular.configs.templateRecommended, ...angular.configs.templateAccessibility], rules: {}, }, )

Change the application prefix in angular.json from app to baf.

Please note that the eslint-plugin-import plugin is not supported in eslint 9.

There is a heated discussion on github - github.com/import-js/eslint-plugin-import/issues/2948

Prettier setting

Add prettier:

yarn add -D prettier

yarn add -D prettier

Let's define the rules in .prettierrc.json:

yarn add -D prettier

{ "bracketSpacing": true, "printWidth": 140, "semi": true, "singleQuote": true, "tabWidth": 2, "useTabs": false }

Exclude everything that should not be formatted in .prettierignore:

yarn add -D prettier

# Add files here to ignore them from prettier formatting /dist /coverage /tmp /node_modules /nginx /.vscode /.idea package-lock.json package.json yarn.lock .angular /junit junit.xml /.nx/cache

In the IDE in the prettier settings - **/*.{js,ts,jsx,tsx,vue,astro,scss,css,html,json}.

Links

All sources are on github, in the repository - github.com/Fafnur/buy-and-fly

The demo can be viewed here - buy-and-fly.fafn.ru/

My groups: telegram, medium, vk, x.com, linkedin, site