feat(lsp): add Dart Language Server support (#9)

* feat(lsp): add Dart Language Server support

Add Dart LSP support with system-first fallback and auto-download:
- Check for system `dart` in PATH first
- Auto-download Dart SDK 3.7.1 if not found
- Support all major platforms: linux-x64, linux-arm64, osx-x64, osx-arm64, win-x64
- Root detection via pubspec.yaml and pubspec.lock

Closes #8

* refactor(lsp): improve Dart LSP implementation

- Extract process event handlers to attachLSPProcessHandlers() helper
- Add documentation explaining setupDartDependencies vs Kotlin pattern
- Add behavioral tests for root detection (pubspec.yaml/pubspec.lock)
- Update CLAUDE.md to include Dart in supported servers table

* test(lsp): add monorepo and deep nesting tests for DartServer

- Add test for nested monorepo package detection (inner pubspec.yaml)
- Add test for deep directory structure root detection

* refactor(lsp): migrate tests to Bun ecosystem pattern

- Move tests from src/__tests__/ to test/ directory
- Add test/unit/ for unit tests
- Add test/integration/ for integration tests
- Add test/fixtures/ for test data
- Create Dart project fixture for LSP integration tests
- Add DartServer integration tests (serena pattern)
- Update package.json with test:unit and test:integration scripts

Directory structure follows Bun/Elysia conventions:
  test/
  ├── unit/           # Unit tests
  ├── integration/    # Integration tests
  └── fixtures/       # Test data

* ci: fix test command for new directory structure

- Use `bun run test` which runs turbo for all packages
- Generate coverage from packages/lsp separately
- Update coverage file path for Codecov

* ci: add Codecov components for monorepo packages

- Create codecov.yml with component configuration
- Define components for each package: code, code-format, code-lsp, dora
- Generate coverage reports for all packages with tests
- Upload multiple coverage files to Codecov

* fix: use single quotes in codecov.yml

Author: amondnet

.github/workflows/ci.yml

@@ -49,12 +49,22 @@ jobs:
       - name: Install dependencies
         run: bun install
 
-      - name: Test with coverage
-        run: bun test --coverage --coverage-reporter=lcov
+      - name: Run tests
+        run: bun run test
+
+      - name: Generate coverage reports
+        run: |
+          cd packages/lsp && bun test --coverage --coverage-reporter=lcov
+          cd ../code && bun test --coverage --coverage-reporter=lcov || true
+          cd ../dora && bun test --coverage --coverage-reporter=lcov || true
+        continue-on-error: true
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          files: ./coverage/lcov.info
+          files: |
+            ./packages/lsp/coverage/lcov.info
+            ./packages/code/coverage/lcov.info
+            ./packages/dora/coverage/lcov.info
           fail_ci_if_error: false

CLAUDE.md

@@ -125,6 +125,7 @@ Claude/MCP Client <-> StdioTransport <-> McpServer <-> Providers
 | Go | gopls | go.mod, go.work |
 | Rust | rust-analyzer | Cargo.toml |
 | Kotlin | JetBrains Kotlin LSP (auto-download) | build.gradle.kts, build.gradle, pom.xml |
+| Dart | dart language-server (auto-download) | pubspec.yaml, pubspec.lock |
 
 ### Built-in Formatters
 

codecov.yml

@@ -0,0 +1,36 @@
+coverage:
+  status:
+    project:
+      default:
+        target: auto
+        threshold: 1%
+    patch:
+      default:
+        target: auto
+
+component_management:
+  default_rules:
+    statuses:
+      - type: project
+        target: auto
+
+  individual_components:
+    - component_id: code
+      name: '@pleaseai/code'
+      paths:
+        - packages/code/src/**
+
+    - component_id: code-format
+      name: '@pleaseai/code-format'
+      paths:
+        - packages/format/src/**
+
+    - component_id: code-lsp
+      name: '@pleaseai/code-lsp'
+      paths:
+        - packages/lsp/src/**
+
+    - component_id: dora
+      name: '@pleaseai/dora'
+      paths:
+        - packages/dora/src/**

packages/lsp/package.json

@@ -25,7 +25,9 @@
   ],
   "scripts": {
     "typecheck": "tsc -p tsconfig.json --noEmit",
-    "test": "bun test ./src"
+    "test": "bun test ./test",
+    "test:unit": "bun test ./test/unit",
+    "test:integration": "bun test ./test/integration"
   },
   "dependencies": {
     "vscode-jsonrpc": "^8.2.1",

packages/lsp/src/index.ts

@@ -392,6 +392,7 @@ export { createLSPClient, type LSPClientInfo } from './client'
 // Re-export specific items to avoid conflicts
 export { getLanguageId, LANGUAGE_EXTENSIONS } from './language'
 export {
+  DartServer,
   DenoServer,
   getServerById,
   getServersForExtension,

packages/lsp/src/server.ts

@@ -130,6 +130,32 @@ async function downloadAndExtract(url: string, destDir: string): Promise<void> {
   }
 }
 
+// =============================================================================
+// Process Lifecycle Utilities
+// =============================================================================
+
+/**
+ * Attach error and exit event handlers to an LSP process
+ * Centralizes logging for process lifecycle events
+ */
+function attachLSPProcessHandlers(
+  proc: ChildProcessWithoutNullStreams,
+  serverId: string,
+): void {
+  proc.on('error', (err) => {
+    console.error(`[${serverId}] LSP process error:`, err)
+  })
+
+  proc.on('exit', (code, signal) => {
+    if (code !== 0 && code !== null) {
+      console.error(`[${serverId}] LSP exited with code ${code}`)
+    }
+    if (signal) {
+      console.error(`[${serverId}] LSP killed by signal ${signal}`)
+    }
+  })
+}
+
 // =============================================================================
 // Root Detection Utilities
 // =============================================================================
@@ -651,24 +677,173 @@ export const KotlinServer: LSPServerInfo = {
         },
       })
 
-      // Log spawn errors
-      proc.on('error', (err) => {
-        console.error(`[kotlin] Kotlin LSP process error:`, err)
-      })
+      attachLSPProcessHandlers(proc, 'kotlin')
+      return { process: proc }
+    }
+    catch (err) {
+      console.error(`[kotlin] Failed to spawn Kotlin LSP:`, err)
+      return undefined
+    }
+  },
+}
+
+// =============================================================================
+// Dart Language Server
+// =============================================================================
 
-      proc.on('exit', (code, signal) => {
-        if (code !== 0 && code !== null) {
-          console.error(`[kotlin] Kotlin LSP exited with code ${code}`)
+/**
+ * Dart SDK runtime dependency configuration
+ * Uses official Dart SDK with built-in language server
+ */
+const DART_RUNTIME_DEPS = {
+  version: '3.7.1',
+  platforms: {
+    'win-x64': {
+      url: 'https://storage.googleapis.com/dart-archive/channels/stable/release/3.7.1/sdk/dartsdk-windows-x64-release.zip',
+      binaryPath: 'dart-sdk/bin/dart.exe',
+    },
+    'linux-x64': {
+      url: 'https://storage.googleapis.com/dart-archive/channels/stable/release/3.7.1/sdk/dartsdk-linux-x64-release.zip',
+      binaryPath: 'dart-sdk/bin/dart',
+    },
+    'linux-arm64': {
+      url: 'https://storage.googleapis.com/dart-archive/channels/stable/release/3.7.1/sdk/dartsdk-linux-arm64-release.zip',
+      binaryPath: 'dart-sdk/bin/dart',
+    },
+    'osx-x64': {
+      url: 'https://storage.googleapis.com/dart-archive/channels/stable/release/3.7.1/sdk/dartsdk-macos-x64-release.zip',
+      binaryPath: 'dart-sdk/bin/dart',
+    },
+    'osx-arm64': {
+      url: 'https://storage.googleapis.com/dart-archive/channels/stable/release/3.7.1/sdk/dartsdk-macos-arm64-release.zip',
+      binaryPath: 'dart-sdk/bin/dart',
+    },
+  } as Record<PlatformId, { url: string, binaryPath: string }>,
+}
+
+/**
+ * Get the Dart LSP resources directory
+ */
+function getDartResourcesDir(): string {
+  return path.join(os.homedir(), '.cache', 'dora', 'dart-lsp')
+}
+
+/**
+ * Setup Dart runtime dependencies
+ * Downloads Dart SDK if not available and dart is not in PATH
+ *
+ * Unlike setupKotlinDependencies which returns { javaHomePath, kotlinLspPath },
+ * this returns only the binary path because:
+ * - Dart SDK is self-contained (no separate JRE dependency)
+ * - No environment variables (like JAVA_HOME) required for execution
+ */
+async function setupDartDependencies(platformId: PlatformId): Promise<string | undefined> {
+  const config = DART_RUNTIME_DEPS.platforms[platformId]
+
+  if (!config) {
+    console.warn(`[dart] Unsupported platform: ${platformId}`)
+    return undefined
+  }
+
+  const resourcesDir = getDartResourcesDir()
+  const dartPath = path.join(resourcesDir, config.binaryPath)
+
+  try {
+    await fs.access(dartPath)
+    return dartPath
+  }
+  catch (err) {
+    const isNotFound = err instanceof Error
+      && 'code' in err
+      && (err as NodeJS.ErrnoException).code === 'ENOENT'
+
+    if (!isNotFound) {
+      console.error(`[dart] Cannot access Dart at ${dartPath}:`, err instanceof Error ? err.message : err)
+      return undefined
+    }
+
+    // Dart not found, download it
+    console.warn(`[dart] Downloading Dart SDK ${DART_RUNTIME_DEPS.version} for ${platformId}...`)
+    try {
+      await downloadAndExtract(config.url, resourcesDir)
+
+      // Make dart executable on Unix platforms
+      if (!platformId.startsWith('win-')) {
+        try {
+          await fs.chmod(dartPath, 0o755)
         }
-        if (signal) {
-          console.error(`[kotlin] Kotlin LSP killed by signal ${signal}`)
+        catch (chmodErr) {
+          console.error(`[dart] Failed to make Dart executable at ${dartPath}:`, chmodErr instanceof Error ? chmodErr.message : chmodErr)
+          return undefined
         }
+      }
+    }
+    catch (downloadErr) {
+      console.error(`[dart] Failed to download Dart SDK:`, downloadErr)
+      return undefined
+    }
+  }
+
+  // Verify Dart exists
+  try {
+    await fs.access(dartPath)
+    return dartPath
+  }
+  catch (err) {
+    const errorMsg = err instanceof Error ? err.message : String(err)
+    console.error(`[dart] Dart executable not accessible at ${dartPath}: ${errorMsg}`)
+    return undefined
+  }
+}
+
+/**
+ * Dart Language Server
+ * Uses official Dart SDK with system-first fallback and auto-download
+ */
+export const DartServer: LSPServerInfo = {
+  id: 'dart',
+  extensions: ['.dart'],
+  root: nearestRoot(['pubspec.yaml', 'pubspec.lock']),
+  async spawn(root) {
+    // Try system dart first
+    const systemDart = Bun.which('dart')
+    if (systemDart) {
+      try {
+        const proc = spawn(systemDart, ['language-server', '--client-id', 'dora.dart', '--client-version', '1.0'], {
+          cwd: root,
+        })
+
+        attachLSPProcessHandlers(proc, 'dart')
+        return { process: proc }
+      }
+      catch (err) {
+        console.warn(`[dart] Failed to spawn system Dart LSP, trying auto-download:`, err)
+      }
+    }
+
+    // Fallback to auto-download
+    const platformId = getPlatformId()
+    if (!platformId) {
+      console.warn(`[dart] Unsupported platform: ${process.platform}-${process.arch}`)
+      return undefined
+    }
+
+    const dartPath = await setupDartDependencies(platformId)
+    if (!dartPath) {
+      console.warn(`[dart] Failed to setup Dart SDK. Check previous logs for details.`)
+      return undefined
+    }
+
+    try {
+      const proc = spawn(dartPath, ['language-server', '--client-id', 'dora.dart', '--client-version', '1.0'], {
+        cwd: root,
       })
 
+      attachLSPProcessHandlers(proc, 'dart')
       return { process: proc }
     }
     catch (err) {
-      console.error(`[kotlin] Failed to spawn Kotlin LSP:`, err)
+      console.error(`[dart] Failed to spawn Dart LSP:`, err)
       return undefined
     }
   },
@@ -685,6 +860,7 @@ export const LSP_SERVERS: LSPServerInfo[] = [
   GoplsServer,
   RustAnalyzerServer,
   KotlinServer,
+  DartServer,
 ]
 
 /**

…src/__tests__/fixture/fake-lsp-server.js …ages/lsp/test/fixture/fake-lsp-server.jspackages/lsp/src/__tests__/fixture/fake-lsp-server.js renamed to packages/lsp/test/fixture/fake-lsp-server.js packages/lsp/src/__tests__/fixture/fake-lsp-server.js renamed to packages/lsp/test/fixture/fake-lsp-server.js

@@ -0,0 +1,17 @@
+/// Standalone subtract function
+int subtract(int a, int b) {
+  return a - b;
+}
+
+/// Divides two numbers with error handling
+double divide(double a, double b) {
+  if (b == 0) {
+    throw ArgumentError('Cannot divide by zero');
+  }
+  return a / b;
+}
+
+/// Formats a number as currency
+String formatCurrency(double amount, {String symbol = '\$'}) {
+  return '$symbol${amount.toStringAsFixed(2)}';
+}

packages/lsp/test/fixtures/dart-project/lib/helper.dart

@@ -0,0 +1,56 @@
+/// Calculator class for basic arithmetic operations
+class Calculator {
+  /// Adds two numbers
+  int add(int a, int b) {
+    final result = a + b;
+    return result;
+  }
+
+  /// Subtracts two numbers
+  int subtract(int a, int b) {
+    return a - b;
+  }
+
+  /// Multiplies two numbers
+  int multiply(int a, int b) {
+    return a * b;
+  }
+}
+
+/// Helper class with static methods
+class MathHelper {
+  /// Calculates power
+  static double power(double base, int exponent) {
+    double result = 1;
+    for (int i = 0; i < exponent; i++) {
+      result *= base;
+    }
+    return result;
+  }
+
+  /// Calculates absolute value
+  static double abs(double value) {
+    return value < 0 ? -value : value;
+  }
+}
+
+/// Main entry point
+void main() {
+  final calc = Calculator();
+
+  // Test arithmetic operations
+  final sum = calc.add(5, 3);
+  final diff = calc.subtract(10, 4);
+  final product = calc.multiply(6, 7);
+
+  print('Sum: $sum');
+  print('Difference: $diff');
+  print('Product: $product');
+
+  // Test helper methods
+  final squared = MathHelper.power(2.0, 3);
+  final absolute = MathHelper.abs(-42.5);
+
+  print('2^3 = $squared');
+  print('|-42.5| = $absolute');
+}

packages/lsp/test/fixtures/dart-project/lib/main.dart

@@ -0,0 +1,6 @@
+name: test_dart_app
+description: Test Dart project for LSP integration tests
+version: 1.0.0
+
+environment:
+  sdk: ^3.0.0