refactor(hooks): simplify Biome detection with process.cwd()

scripts/hooks/post-edit-format.js

@@ -5,90 +5,69 @@
  * Cross-platform (Windows, macOS, Linux)
  *
  * Runs after Edit tool use. If the edited file is a JS/TS file,
- * auto-detects the project formatter (Biome or Prettier) by looking
- * for config files, then formats accordingly.
- * Fails silently if no formatter is found or installed.
+ * detects Biome or Prettier and formats accordingly.
+ * Honors CLAUDE_PACKAGE_MANAGER env var for the exec runner.
+ * Fails silently if no formatter is installed.
  */
 
-const { execFileSync } = require('child_process');
-const fs = require('fs');
-const path = require('path');
+const { execFileSync } = require("child_process");
+const fs = require("fs");
+const path = require("path");
 
 const MAX_STDIN = 1024 * 1024; // 1MB limit
-let data = '';
-process.stdin.setEncoding('utf8');
+const JS_TS_EXT = /\.(ts|tsx|js|jsx)$/;
+const BIOME_CONFIGS = ["biome.json", "biome.jsonc"];
 
-process.stdin.on('data', chunk => {
-  if (data.length < MAX_STDIN) {
-    const remaining = MAX_STDIN - data.length;
-    data += chunk.substring(0, remaining);
-  }
-});
+// Use local-first runners (not dlx/download) since this hook runs on every edit
+const RUNNERS = {
+  npm: { bin: "npx", args: [] },
+  pnpm: { bin: "pnpm", args: ["exec"] },
+  yarn: { bin: "yarn", args: ["exec"] },
+  bun: { bin: "bunx", args: [] },
+};
 
-function findProjectRoot(startDir) {
-  let dir = startDir;
-  while (dir !== path.dirname(dir)) {
-    if (fs.existsSync(path.join(dir, 'package.json'))) return dir;
-    dir = path.dirname(dir);
-  }
-  return startDir;
+function getRunner() {
+  const pm = process.env.CLAUDE_PACKAGE_MANAGER;
+  const runner = pm && RUNNERS[pm] ? RUNNERS[pm] : RUNNERS.npm;
+  const bin =
+    process.platform === "win32" && !runner.bin.endsWith(".cmd")
+      ? `${runner.bin}.cmd`
+      : runner.bin;
+  return { bin, prefixArgs: runner.args };
 }
 
-function detectFormatter(projectRoot) {
-  const biomeConfigs = ['biome.json', 'biome.jsonc'];
-  for (const cfg of biomeConfigs) {
-    if (fs.existsSync(path.join(projectRoot, cfg))) return 'biome';
-  }
-
-  const prettierConfigs = [
-    '.prettierrc',
-    '.prettierrc.json',
-    '.prettierrc.js',
-    '.prettierrc.cjs',
-    '.prettierrc.mjs',
-    '.prettierrc.yml',
-    '.prettierrc.yaml',
-    '.prettierrc.toml',
-    'prettier.config.js',
-    'prettier.config.cjs',
-    'prettier.config.mjs',
-  ];
-  for (const cfg of prettierConfigs) {
-    if (fs.existsSync(path.join(projectRoot, cfg))) return 'prettier';
-  }
-
-  return null;
-}
+let data = "";
+process.stdin.setEncoding("utf8");
 
-function getFormatterCommand(formatter, filePath) {
-  const npxBin = process.platform === 'win32' ? 'npx.cmd' : 'npx';
-  if (formatter === 'biome') {
-    return { bin: npxBin, args: ['@biomejs/biome', 'format', '--write', filePath] };
-  }
-  if (formatter === 'prettier') {
-    return { bin: npxBin, args: ['prettier', '--write', filePath] };
+process.stdin.on("data", (chunk) => {
+  if (data.length < MAX_STDIN) {
+    const remaining = MAX_STDIN - data.length;
+    data += chunk.substring(0, remaining);
   }
-  return null;
-}
+});
 
-process.stdin.on('end', () => {
+process.stdin.on("end", () => {
   try {
-    const input = JSON.parse(data);
-    const filePath = input.tool_input?.file_path;
+    const { tool_input } = JSON.parse(data);
+    const filePath = tool_input?.file_path;
+
+    if (filePath && JS_TS_EXT.test(filePath)) {
+      const cwd = process.cwd();
+      const hasBiome = BIOME_CONFIGS.some((f) =>
+        fs.existsSync(path.join(cwd, f)),
+      );
 
-    if (filePath && /\.(ts|tsx|js|jsx)$/.test(filePath)) {
       try {
-        const projectRoot = findProjectRoot(path.dirname(path.resolve(filePath)));
-        const formatter = detectFormatter(projectRoot);
-        const cmd = getFormatterCommand(formatter, filePath);
+        const { bin, prefixArgs } = getRunner();
+        const args = hasBiome
+          ? [...prefixArgs, "@biomejs/biome", "check", "--write", filePath]
+          : [...prefixArgs, "prettier", "--write", filePath];
 
-        if (cmd) {
-          execFileSync(cmd.bin, cmd.args, {
-            cwd: projectRoot,
-            stdio: ['pipe', 'pipe', 'pipe'],
-            timeout: 15000
-          });
-        }
+        execFileSync(bin, args, {
+          cwd,
+          stdio: ["pipe", "pipe", "pipe"],
+          timeout: 15000,
+        });
       } catch {
         // Formatter not installed, file missing, or failed — non-blocking
       }