Feature/migrate command

CHANGELOG.md

@@ -7,7 +7,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [0.1.0] - 2024-XX-XX
+### Added
+
+- **`migrate` command** — Migrate existing projects from ESLint/Prettier to Biome
+  - Automatic ESLint config migration (uses Biome's official `biome migrate eslint`)
+  - Automatic Prettier config migration (`biome migrate prettier`)
+  - **Preserves Prettier settings** (quotes, semicolons, trailing commas, line width)
+  - **Auto-detects and excludes generated folders** (`gen/`, `dist/`, `build/`)
+  - **Reads ESLint ignorePatterns** and applies them to Biome
+  - **Jest/Vitest globals** automatically configured
+  - **Optional auto-format** to apply Biome formatting in one commit
+  - Smart dependency cleanup (detects all ESLint/Prettier plugins with regex)
+  - Git safety commit before migration
+  - Interactive prompts for relaxed rules, script updates, and cleanup
+  - `--dry-run` mode for previewing changes
+  - Project detection for ESLint, Prettier, and existing Biome configs
+  - Biome version validation (requires ≥1.7)
+
 
 ### Added
 

README.md

@@ -4,12 +4,21 @@
 
 ## Quick Start
 
+### Create a New Project
+
 ```bash
 npx zero-setup-biome my-app
 cd my-app
 npm run dev
 ```
 
+### Migrate Existing Project
+
+```bash
+cd your-existing-project
+npx zero-setup-biome migrate
+```
+
 That's it. No ESLint/Prettier conflicts. No configuration hell. Just code.
 
 ## What You Get
@@ -20,20 +29,48 @@ That's it. No ESLint/Prettier conflicts. No configuration hell. Just code.
 - 🎨 **VSCode Integration** — Format on save, auto-organize imports
 - 🔒 **Zero Conflicts** — No ESLint vs Prettier wars
 
-## Options
+## Commands
+
+### Create
 
 ```bash
 npx zero-setup-biome <project-name> [options]
 
 Options:
   -t, --template <template>  Template to use (react-ts) [default: react-ts]
-  --skip-install            Skip installing dependencies
-  --skip-git                Skip git initialization
-  --pm <package-manager>    Package manager (npm, pnpm, yarn, bun)
-  -v, --version             Output version number
-  -h, --help                Display help
+  --skip-install             Skip installing dependencies
+  --skip-git                 Skip git initialization
+  --pm <package-manager>     Package manager (npm, pnpm, yarn, bun)
+  -v, --version              Output version number
+  -h, --help                 Display help
+```
+
+### Migrate
+
+Migrate existing projects from ESLint/Prettier to Biome:
+
+```bash
+npx zero-setup-biome migrate [options]
+
+Options:
+  --skip-install   Skip installing Biome
+  --skip-cleanup   Keep ESLint/Prettier configs and dependencies
+  --skip-git       Skip creating safety git commit
+  --dry-run        Show changes without applying them
+  -h, --help       Display help
 ```
 
+**What it does:**
+- ✅ Migrates ESLint rules to `biome.json` (uses Biome's official migration)
+- ✅ Migrates Prettier config to `biome.json`
+- ✅ **Preserves your Prettier settings** (quotes, semicolons, line width, etc.)
+- ✅ **Auto-detects Jest/Vitest** and adds global variables
+- ✅ **Excludes generated folders** (`gen/`, `dist/`, `build/`, etc.)
+- ✅ Removes ESLint/Prettier dependencies and plugins
+- ✅ Updates `package.json` scripts
+- ✅ **Optional auto-format** to apply Biome formatting in one commit
+- ✅ Creates a safety git commit before changes
+
 ## Why Biome?
 
 | Tool | Lint Time (medium project) |

package.json

@@ -27,12 +27,14 @@
     "commander": "^12.1.0",
     "execa": "^9.5.2",
     "fs-extra": "^11.2.0",
-    "picocolors": "^1.1.1"
+    "picocolors": "^1.1.1",
+    "semver": "^7.7.3"
   },
   "devDependencies": {
     "@biomejs/biome": "^2.0.6",
     "@types/fs-extra": "^11.0.4",
     "@types/node": "^22.10.1",
+    "@types/semver": "^7.7.1",
     "@vitest/coverage-v8": "^4.0.15",
     "tsup": "^8.3.5",
     "tsx": "^4.19.2",

src/cli.ts

@@ -1,5 +1,6 @@
 import { Command } from "commander";
 import { runCreate } from "./commands/create.js";
+import { runMigrate } from "./commands/migrate.js";
 import type { PackageManager, Template } from "./types/index.js";
 import { TEMPLATES, VERSION } from "./utils/constants.js";
 
@@ -34,4 +35,20 @@ program
     });
   });
 
+program
+  .command("migrate")
+  .description("Migrate existing project from ESLint/Prettier to Biome")
+  .option("--skip-install", "Skip installing Biome", false)
+  .option("--skip-cleanup", "Keep ESLint/Prettier configs and dependencies", false)
+  .option("--skip-git", "Skip creating safety git commit", false)
+  .option("--dry-run", "Show changes without applying them", false)
+  .action(async (opts) => {
+    await runMigrate({
+      skipInstall: opts.skipInstall,
+      skipCleanup: opts.skipCleanup,
+      skipGit: opts.skipGit,
+      dryRun: opts.dryRun,
+    });
+  });
+
 program.parse();