ESLint configured

Without ESLint or Biome, code quality issues — unused variables, implicit any, unsafe type assertions, missing await, console.log in production — are caught only by the developer's own review discipline rather than automatically on every commit. ISO 25010:2011 §6.5.4 classifies absent static analysis as a maintainability defect. The practical effect: every code review must manually check for issues that a linter would flag in milliseconds, and issues that slip through become permanent residents of the codebase.

Set up ESLint with TypeScript support and wire it into CI. A minimal configuration:

npm install -D eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin

// eslint.config.mjs
import tseslint from '@typescript-eslint/eslint-plugin'
import tsparser from '@typescript-eslint/parser'

export default [
  {
    files: ['**/*.ts', '**/*.tsx'],
    languageOptions: { parser: tsparser },
    plugins: { '@typescript-eslint': tseslint },
    rules: {
      ...tseslint.configs.recommended.rules,
      '@typescript-eslint/no-explicit-any': 'error',
      '@typescript-eslint/no-unused-vars': 'error',
      'no-console': ['error', { allow: ['error', 'warn'] }],
    },
  },
]

Add to package.json:

{ "scripts": { "lint": "eslint src/ --max-warnings=0" } }

• ID: eslint-configured

• Severity: low

• What to look for: Check for ESLint configuration files: eslint.config.js, eslint.config.mjs, .eslintrc.js, .eslintrc.cjs, .eslintrc.json, .eslintrc.yaml. Alternatively, check for Biome (biome.json) which serves as a combined linter and formatter. Verify that the configuration extends appropriate rulesets: eslint:recommended for base JavaScript, @typescript-eslint/recommended or @typescript-eslint/strict for TypeScript. Check whether a lint script is in package.json. Look for ESLint in devDependencies. A missing ESLint configuration means code quality issues (unused variables, implicit any, unsafe patterns) are caught only by the developer's judgment rather than automatically on every commit.

• Pass criteria: Enumerate all relevant code locations. ESLint or Biome is configured, extends a TypeScript-aware ruleset, and is run via a lint script. The lint script runs in CI with at least 1 verified location.

• Fail criteria: No ESLint or Biome configuration found. A partial implementation does not count as pass.

• Skip (N/A) when: Never — linting applies to all JavaScript/TypeScript projects.

• Cross-reference: Compare with code-quality-essentials.organization.naming-conventions — ESLint enforces naming rules programmatically while naming-conventions evaluates adherence manually.

• Detail on fail: "No ESLint configuration found; code quality issues are not automatically caught during development or CI"

• Remediation: Set up ESLint with TypeScript support:

  npm install -D eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin
  

  // eslint.config.mjs
  import tseslint from '@typescript-eslint/eslint-plugin'
  import tsparser from '@typescript-eslint/parser'
  
  export default [
    {
      files: ['**/*.ts', '**/*.tsx'],
      languageOptions: { parser: tsparser },
      plugins: { '@typescript-eslint': tseslint },
      rules: {
        ...tseslint.configs.recommended.rules,
        '@typescript-eslint/no-explicit-any': 'error',
        '@typescript-eslint/no-unused-vars': 'error',
        'no-console': ['error', { allow: ['error', 'warn'] }],
      },
    },
  ]
  

  Add to package.json:

  { "scripts": { "lint": "eslint src/ --max-warnings=0" } }