Add reanalyze server support, monorepo build support, and comprehensive integration tests.

## Summary

Add reanalyze server support, monorepo build support, and comprehensive integration tests.

---

## 1. Fixes

### ARM64 binary lookup fallback
**File:** `shared/src/findBinary.ts`
- For ARM64 architecture, try the arm64-specific directory first (e.g., `darwinarm64`), then fall back to the generic platform directory (e.g., `darwin`) for older ReScript versions that don't have arm64-specific directories

### Fixed "rescript" JS wrapper lookup
**File:** `shared/src/findBinary.ts`
- For the "rescript" JS wrapper (as opposed to native binaries like `bsc.exe`), don't use the `bsc_path` directory from `compiler-info.json` - fall through to find the JS wrapper in node_modules/.bin instead

### Build watcher process cleanup
**File:** `server/src/utils.ts`
- Added `killBuildWatcher()` function that properly kills the entire process group (not just the parent process) and cleans up lock files
- Uses `process.kill(-proc.pid, "SIGTERM")` on Unix to kill the entire process group, ensuring child processes (like the native rescript binary) are also killed
- The rescript compiler doesn't remove lock files on SIGTERM, so we now clean them up manually

### Build watcher stdin handling for older ReScript
**File:** `server/src/utils.ts`
- Use "pipe" for stdin instead of "ignore" because older ReScript versions (9.x, 10.x, 11.x) have a handler that exits when stdin closes: `process.stdin.on("close", exitProcess)`

### Server shutdown cleanup
**File:** `server/src/server.ts`
- Kill all build watchers and clean up lock files on LSP server shutdown

---

## 2. New Functionality

### Reanalyze Server Support (ReScript >= 12.1.0)
**Files:** `client/src/commands/code_analysis.ts`, `client/src/commands.ts`, `client/src/extension.ts`
- Added persistent reanalyze-server support for ReScript >= 12.1.0 (uses Unix socket for incremental analysis)
- Server state management per monorepo root
- Functions: `startReanalyzeServer()`, `stopReanalyzeServer()`, `stopAllReanalyzeServers()`, `showReanalyzeServerLog()`
- Dedicated output channels for server logs per project
- Automatic socket file cleanup
- Servers are stopped when code analysis is stopped or extension deactivates

### New Command: Show Reanalyze Server Log
**Files:** `client/src/extension.ts`, `package.json`
- New command: `rescript-vscode.show_reanalyze_server_log`
- Displays the reanalyze server output channel for debugging

### New Command: Start Build
**Files:** `client/src/extension.ts`, `server/src/server.ts`, `package.json`
- New command: `rescript-vscode.start_build`
- Allows manually starting the build watcher without waiting for the prompt
- LSP request handler: `rescript/startBuild`

### Monorepo Support
**Files:** `shared/src/findBinary.ts`, `server/src/server.ts`, `server/src/utils.ts`, `client/src/commands/code_analysis.ts`
- New function `getMonorepoRootFromBinaryPath()` to derive monorepo root from binary path
- Build watcher now runs from monorepo root, not subpackage directory
- Lock file detection at monorepo root level (checks both `lib/rescript.lock` and `.bsb.lock`)
- Build prompt correctly uses monorepo root path when opening files from subpackages
- Tracks `buildRootPath` separately from `projectRootPath` for proper cleanup

### ReScript Version-Aware Build Command
**File:** `server/src/utils.ts`
- Uses `rescript watch` for ReScript >= 12.0.0
- Uses `rescript build -w` for ReScript < 12.0.0

### Improved Error Handling and Logging
**Files:** Multiple
- Better error messages when binaries are not found
- Logging for build watcher process lifecycle (start, error, exit)
- Logging for file open/close events

---

## 3. Tests

### Test Infrastructure
**Files:** `client/package.json`, `client/.vscode-test.mjs`, `client/tsconfig.json`
- Added test dependencies: `@types/mocha`, `@vscode/test-cli`, `@vscode/test-electron`
- Test configuration for 4 test suites with different workspace folders
- Added `skipLibCheck: true` to tsconfig for test type compatibility

### Test Helpers (`client/src/test/suite/helpers.ts`)
Shared utilities for all test suites:
- `getWorkspaceRoot()` - Get workspace folder path
- `removeRescriptLockFile()`, `removeBsbLockFile()`, `removeMonorepoLockFiles()` - Lock file cleanup
- `removeReanalyzeSocketFile()` - Socket file cleanup
- `ensureExtensionActivated()` - Ensure extension is active
- `openFile()` - Open file in editor
- `findLspLogContent()` - Read LSP logs for verification
- `waitFor()`, `sleep()` - Async utilities
- `getCompilerLogPath()`, `getFileMtime()`, `waitForFileUpdate()` - File modification tracking
- `insertCommentAndSave()`, `restoreContentAndSave()` - Edit and restore files
- `startBuildWatcher()`, `startCodeAnalysis()`, `stopCodeAnalysis()` - Command execution
- `showReanalyzeServerLog()`, `findBuildPromptInLogs()` - Verification helpers

### Example Project Tests (`client/src/test/suite/exampleProject.test.ts`)
Tests against `analysis/examples/example-project/` (ReScript 12.1.0):
1. **Extension should be present** - Verify extension loads
2. **Commands should be registered** - Verify all new commands are registered
3. **Start Code Analysis should run** - Run code analysis on a ReScript file
4. **Start Build command should start build watcher** - Manual build start
5. **Build watcher recompiles on file save** - Edit file, verify compiler.log updates
6. **Code analysis with incremental updates** - Add dead code, verify new diagnostics appear
7. **Should prompt to start build when no lock file exists** - Verify build prompt

### Monorepo Root Tests (`client/src/test/suite/monorepoRoot.test.ts`)
Tests against `analysis/examples/monorepo-project/` opened at root:
1. **Build watcher works when opening root package** - Build from root, verify compiler.log
2. **Build watcher works when opening subpackage file** - Open subpackage file, build still uses root compiler.log
3. **Code analysis works from subpackage** - Run reanalyze from lib package
4. **Should prompt to start build with monorepo root path** - Open subpackage, prompt uses root path

### Monorepo Subpackage Tests (`client/src/test/suite/monorepoSubpackage.test.ts`)
Tests against `analysis/examples/monorepo-project/packages/app/` (VSCode opened on subpackage):
1. **Should prompt to start build with monorepo root path** - Even when opened from subpackage, prompt uses monorepo root
2. **Lock file created at monorepo root, not subpackage** - Verify lock file location
3. **Code analysis works when opened from subpackage** - Diagnostics shown correctly

### ReScript 9 Tests (`client/src/test/suite/rescript9.test.ts`)
Tests against `analysis/examples/rescript9-project/` (ReScript 9.x):
1. **Extension should be present** - Extension loads with older ReScript
2. **Build watcher should start with 'rescript build -w'** - Not 'rescript watch'
3. **Build watcher recompiles on file save** - Verify incremental compilation
4. **Should prompt to start build when no lock file exists** - Uses `.bsb.lock`
5. **Lock file should be cleaned up on language server restart** - Verify cleanup

### Test Projects Added
- `analysis/examples/monorepo-project/` - Monorepo with root package + packages/app + packages/lib
- `analysis/examples/rescript9-project/` - ReScript 9.x project with bsconfig.json
- Updated `analysis/examples/example-project/` to use ReScript 12.1.0

---

## Other Changes

### .gitignore
- Added `.vscode-test/` directory (VSCode test downloads)

### package.json (root)
- Added two new commands to the extension manifest:
  - `rescript-vscode.show_reanalyze_server_log` - "ReScript: Show Code Analyzer Server Log"
  - `rescript-vscode.start_build` - "ReScript: Start Build"

Author: cristianoc

.gitignore

@@ -24,4 +24,7 @@ rescript-tools.exe
 _opam/
 _build/
 
-*.tsbuildinfo
+*.tsbuildinfo
+
+# VSCode test downloads
+.vscode-test/

analysis/examples/example-project/.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "rescript.settings.logLevel": "log"
+}

analysis/examples/example-project/package.json

@@ -2,12 +2,12 @@
   "name": "tryit",
   "dependencies": {
     "@rescript/react": "^0.14.0",
-    "rescript": "12.0.2"
+    "rescript": "12.1.0"
   },
   "scripts": {
-    "build": "rescript-legacy",
-    "start": "rescript-legacy build -w",
-    "clean": "rescript-legacy clean -with-deps",
+    "build": "rescript",
+    "start": "rescript build -w",
+    "clean": "rescript clean",
     "format": "rescript format"
   }
 }

analysis/examples/monorepo-project/.gitignore

@@ -0,0 +1,2 @@
+lib
+.merlin

analysis/examples/monorepo-project/.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "rescript.settings.logLevel": "log"
+}

analysis/examples/monorepo-project/package-lock.json

@@ -0,0 +1,16 @@
+{
+  "name": "monorepo-project",
+  "private": true,
+  "workspaces": [
+    "packages/app",
+    "packages/lib"
+  ],
+  "dependencies": {
+    "rescript": "12.1.0"
+  },
+  "scripts": {
+    "build": "rescript build",
+    "watch": "rescript watch",
+    "clean": "rescript clean"
+  }
+}

analysis/examples/monorepo-project/package.json

@@ -0,0 +1,3 @@
+{
+  "rescript.settings.logLevel": "log"
+}

analysis/examples/monorepo-project/packages/app/.vscode/settings.json

@@ -0,0 +1,12 @@
+{
+  "name": "@monorepo/app",
+  "version": "0.0.1",
+  "scripts": {
+    "build": "rescript build",
+    "clean": "rescript clean",
+    "watch": "rescript watch"
+  },
+  "dependencies": {
+    "@monorepo/lib": "*"
+  }
+}

analysis/examples/monorepo-project/packages/app/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@monorepo/app",
+  "sources": {
+    "dir": "src",
+    "subdirs": true
+  },
+  "package-specs": {
+    "module": "esmodule",
+    "in-source": true
+  },
+  "suffix": ".mjs",
+  "dependencies": ["@monorepo/lib"]
+}