JavaScript

JavaScript and TypeScript projects use ESLint for linting, Prettier for formatting, npm audit for security scanning, Vitest for testing, and tsc for type checking. A single javascript entry in .devrail.yml covers both languages.

Tools

All tools are pre-installed in the dev-toolchain container. Do not install them on the host.

Configuration

ESLint

Config file: eslint.config.js (flat config) at repository root.

// eslint.config.js -- DevRail JS/TS lint configuration
import eslint from "@eslint/js";
import tseslint from "typescript-eslint";

export default tseslint.config(
  eslint.configs.recommended,
  tseslint.configs.recommended,
  {
    ignores: ["node_modules/", "dist/", "build/", "coverage/"],
  }
);

For JavaScript-only projects (no TypeScript):

// eslint.config.js -- DevRail JS-only lint configuration
import eslint from "@eslint/js";

export default [
  eslint.configs.recommended,
  {
    ignores: ["node_modules/", "dist/", "build/", "coverage/"],
  },
];

ESLint v9 uses flat config (eslint.config.js), not the legacy .eslintrc format. The @eslint/js and typescript-eslint packages are installed globally in the container so flat config imports resolve without project-local node_modules.

Prettier

Config file: .prettierrc at repository root.

{
  "semi": true,
  "singleQuote": false,
  "trailingComma": "es5",
  "printWidth": 80,
  "tabWidth": 2
}

A .prettierignore file is required to exclude generated files:

node_modules/
dist/
build/
coverage/

Prettier formats JS, TS, JSON, CSS, and Markdown files. The .prettierignore controls scope.

TypeScript

Config file: tsconfig.json at repository root. When present, tsc --noEmit runs as part of make lint.

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "strict": true,
    "noEmit": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "resolveJsonModule": true,
    "isolatedModules": true
  },
  "include": ["src"],
  "exclude": ["node_modules", "dist", "build"]
}

Vitest

Config file: vitest.config.ts (or vitest.config.js) at repository root.

import { defineConfig } from "vitest/config";

export default defineConfig({
  test: {
    globals: true,
    environment: "node",
    coverage: {
      reporter: ["text", "json", "html"],
    },
  },
});

Makefile Targets

Pre-Commit Hooks

Local Hooks (run on every commit, under 30 seconds)

ESLint and Prettier run on every commit to catch lint and formatting issues:

# .pre-commit-config.yaml -- JavaScript/TypeScript hooks
repos:
  - repo: https://github.com/pre-commit/mirrors-eslint
    rev: v9.27.0
    hooks:
      - id: eslint
        additional_dependencies:
          - eslint
          - "@eslint/js"
          - typescript-eslint
          - typescript

  - repo: https://github.com/pre-commit/mirrors-prettier
    rev: v4.0.0-alpha.8
    hooks:
      - id: prettier

CI-Only (too slow for local hooks)

• npm audit --audit-level=moderate – dependency vulnerability scanning
• vitest run – full test suite

Notes

• Single javascript entry covers both JS and TS. Do not add a separate typescript entry to .devrail.yml. TypeScript support auto-activates when tsconfig.json is present.
• ESLint v9 uses flat config. The config file is eslint.config.js (not .eslintrc). The @eslint/js and typescript-eslint packages provide rule configurations for the flat config format.
• tsc runs under make lint, not a separate target. Type checking is static analysis (like mypy for Python). It is gated on tsconfig.json presence.
• Prettier formats more than JS/TS. Prettier handles JSON, CSS, Markdown, and other file types. Projects must use .prettierignore to exclude generated files.
• npm audit gates on package-lock.json. If no package-lock.json exists, npm audit is skipped because there are no locked dependencies to scan.
• Vitest gates on test file presence. If no *.test.* or *.spec.* files exist, vitest is skipped.
• All tools are pre-installed in the dev-toolchain container. Do not install them on the host.