feat(code): port posthog detection logic to new pkg

Author: adboio

mprocs.yaml

@@ -13,6 +13,9 @@ procs:
   git:
     shell: 'node scripts/pnpm-run.mjs --filter @posthog/git run dev'
 
+  detect:
+    shell: 'node scripts/pnpm-run.mjs --filter @posthog/detect run dev'
+
   storybook:
     shell: 'node scripts/pnpm-run.mjs --filter code run storybook'
     autostart: false

packages/detect/grammars/tree-sitter-go.wasm

@@ -0,0 +1,34 @@
+{
+  "name": "@posthog/detect",
+  "version": "1.0.0",
+  "description": "Detect PostHog SDK usage in source code via tree-sitter AST analysis",
+  "type": "module",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    }
+  },
+  "scripts": {
+    "build": "tsup",
+    "dev": "tsup --watch",
+    "typecheck": "tsc --noEmit",
+    "clean": "node ../../scripts/rimraf.mjs dist .turbo",
+    "fetch-grammars": "node scripts/fetch-grammars.cjs",
+    "test": "vitest run"
+  },
+  "dependencies": {
+    "web-tree-sitter": "^0.24.7"
+  },
+  "devDependencies": {
+    "tree-sitter-cli": "^0.26.6",
+    "tsup": "^8.5.1",
+    "typescript": "^5.5.0",
+    "vitest": "^2.1.9"
+  },
+  "files": [
+    "dist/**/*",
+    "src/**/*",
+    "grammars/**/*"
+  ]
+}

packages/detect/grammars/tree-sitter-javascript.wasm

@@ -0,0 +1,137 @@
+#!/usr/bin/env node
+
+/**
+ * Builds tree-sitter WASM grammar files for all supported languages.
+ * Requires: tree-sitter-cli and emscripten (or docker).
+ *
+ * Usage: node scripts/fetch-grammars.cjs
+ *
+ * If tree-sitter CLI cannot build WASM (no emscripten), you can manually
+ * place pre-built .wasm files in the grammars/ directory.
+ *
+ * Copied from posthog-vscode/scripts/fetch-grammars.js
+ */
+
+const { execSync } = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+const GRAMMARS_DIR = path.join(__dirname, '..', 'grammars');
+
+function hasCli() {
+    try {
+        execSync('npx tree-sitter --version', { stdio: 'pipe' });
+        return true;
+    } catch {
+        return false;
+    }
+}
+
+function buildGrammar(grammarPkg, outputName, subDir) {
+    const dest = path.join(GRAMMARS_DIR, outputName);
+    if (fs.existsSync(dest) && fs.statSync(dest).size > 10000) {
+        const size = (fs.statSync(dest).size / 1024).toFixed(0);
+        console.log(`  ✓ ${outputName} (${size}KB, cached)`);
+        return true;
+    }
+
+    const tempDir = path.join(__dirname, '..', '.grammar-build');
+    if (!fs.existsSync(tempDir)) {
+        fs.mkdirSync(tempDir, { recursive: true });
+    }
+
+    // Strip version specifier from package name for the directory path
+    const dirName = grammarPkg.replace(/@[\d.]+.*$/, '');
+    const grammarDir = path.join(tempDir, 'node_modules', dirName);
+    if (!fs.existsSync(grammarDir)) {
+        process.stdout.write(`  ↓ Installing ${grammarPkg}...`);
+        try {
+            execSync(`npm install ${grammarPkg} --prefix "${tempDir}" --ignore-scripts`, {
+                stdio: 'pipe',
+                cwd: tempDir,
+            });
+            console.log(' OK');
+        } catch (err) {
+            console.log(` FAILED`);
+            return false;
+        }
+    }
+
+    const buildDir = subDir ? path.join(grammarDir, subDir) : grammarDir;
+    process.stdout.write(`  ⚙ Building ${outputName}...`);
+    try {
+        execSync(`npx tree-sitter build --wasm -o "${dest}"`, {
+            stdio: 'pipe',
+            cwd: buildDir,
+            timeout: 120000,
+        });
+        const size = (fs.statSync(dest).size / 1024).toFixed(0);
+        console.log(` ${size}KB`);
+        return true;
+    } catch (err) {
+        const stderr = err.stderr ? err.stderr.toString().trim() : '';
+        const stdout = err.stdout ? err.stdout.toString().trim() : '';
+        const msg = stderr || stdout || err.message || '';
+        console.log(` FAILED`);
+        if (msg) { console.log(`    → ${msg}`); }
+        return false;
+    }
+}
+
+function main() {
+    if (!fs.existsSync(GRAMMARS_DIR)) {
+        fs.mkdirSync(GRAMMARS_DIR, { recursive: true });
+    }
+
+    // Copy the core tree-sitter runtime WASM
+    const runtimeSrc = path.join(__dirname, '..', 'node_modules', 'web-tree-sitter', 'tree-sitter.wasm');
+    const altRuntimeSrc = path.join(__dirname, '..', '..', '..', 'node_modules', 'web-tree-sitter', 'tree-sitter.wasm');
+    const runtimeDest = path.join(GRAMMARS_DIR, 'tree-sitter.wasm');
+    const src = fs.existsSync(runtimeSrc) ? runtimeSrc : altRuntimeSrc;
+    if (fs.existsSync(src)) {
+        fs.copyFileSync(src, runtimeDest);
+        const size = (fs.statSync(runtimeDest).size / 1024).toFixed(0);
+        console.log(`  ✓ tree-sitter.wasm runtime (${size}KB)`);
+    }
+
+    console.log('\nBuilding tree-sitter grammar WASM files...\n');
+
+    if (!hasCli()) {
+        console.log('⚠ tree-sitter CLI not found. Install it:');
+        console.log('  npm install -g tree-sitter-cli\n');
+        console.log('Then re-run: node scripts/fetch-grammars.cjs');
+        process.exit(1);
+    }
+
+    let built = 0;
+
+    // JavaScript — pinned to 0.23.1 for ABI v14 compatibility with web-tree-sitter@0.24.x
+    if (buildGrammar('tree-sitter-javascript@0.23.1', 'tree-sitter-javascript.wasm')) built++;
+
+    // TypeScript (has typescript/ and tsx/ sub-directories)
+    if (buildGrammar('tree-sitter-typescript', 'tree-sitter-typescript.wasm', 'typescript')) built++;
+    if (buildGrammar('tree-sitter-typescript', 'tree-sitter-tsx.wasm', 'tsx')) built++;
+
+    // Python — pinned to 0.23.5 for ABI v14 compatibility with web-tree-sitter@0.24.x
+    if (buildGrammar('tree-sitter-python@0.23.5', 'tree-sitter-python.wasm')) built++;
+
+    // Go — pinned to 0.23.4 for ABI v14 compatibility with web-tree-sitter@0.24.x
+    if (buildGrammar('tree-sitter-go@0.23.4', 'tree-sitter-go.wasm')) built++;
+
+    // Ruby — pinned to 0.23.1 for ABI v14 compatibility with web-tree-sitter@0.24.x
+    if (buildGrammar('tree-sitter-ruby@0.23.1', 'tree-sitter-ruby.wasm')) built++;
+
+    // Cleanup temp dir
+    const tempDir = path.join(__dirname, '..', '.grammar-build');
+    try { fs.rmSync(tempDir, { recursive: true, force: true }); } catch { /* */ }
+
+    console.log(`\n${built} grammar(s) ready in grammars/`);
+
+    if (built === 0) {
+        console.log('\n⚠ No grammars were built. You may need emscripten installed.');
+        console.log('  See: https://emscripten.org/docs/getting_started/downloads.html');
+        console.log('  Or use Docker: tree-sitter build --wasm --docker');
+    }
+}
+
+main();