fix(hooks): respect package manager in formatter fallback

Author: tsubasakong

scripts/hooks/post-edit-format.js

@@ -13,6 +13,7 @@
 const { execFileSync } = require('child_process');
 const fs = require('fs');
 const path = require('path');
+const { getPackageManager } = require('../lib/package-manager');
 
 const MAX_STDIN = 1024 * 1024; // 1MB limit
 let data = '';
@@ -60,13 +61,42 @@ function detectFormatter(projectRoot) {
   return null;
 }
 
-function getFormatterCommand(formatter, filePath) {
-  const npxBin = process.platform === 'win32' ? 'npx.cmd' : 'npx';
+function getRunnerBin(bin) {
+  if (process.platform !== 'win32') return bin;
+
+  if (bin === 'npx') return 'npx.cmd';
+  if (bin === 'pnpm') return 'pnpm.cmd';
+  if (bin === 'yarn') return 'yarn.cmd';
+  if (bin === 'bunx') return 'bunx.cmd';
+
+  return bin;
+}
+
+function getFormatterRunner(projectRoot) {
+  const pm = getPackageManager({ projectDir: projectRoot });
+  const execCmd = pm?.config?.execCmd || 'npx';
+  const [bin = 'npx', ...prefix] = execCmd.split(/\s+/).filter(Boolean);
+
+  return {
+    bin: getRunnerBin(bin),
+    prefix
+  };
+}
+
+function getFormatterCommand(formatter, filePath, projectRoot) {
+  const runner = getFormatterRunner(projectRoot);
+
   if (formatter === 'biome') {
-    return { bin: npxBin, args: ['@biomejs/biome', 'format', '--write', filePath] };
+    return {
+      bin: runner.bin,
+      args: [...runner.prefix, '@biomejs/biome', 'format', '--write', filePath]
+    };
   }
   if (formatter === 'prettier') {
-    return { bin: npxBin, args: ['prettier', '--write', filePath] };
+    return {
+      bin: runner.bin,
+      args: [...runner.prefix, 'prettier', '--write', filePath]
+    };
   }
   return null;
 }
@@ -80,7 +110,7 @@ process.stdin.on('end', () => {
       try {
         const projectRoot = findProjectRoot(path.dirname(path.resolve(filePath)));
         const formatter = detectFormatter(projectRoot);
-        const cmd = getFormatterCommand(formatter, filePath);
+        const cmd = getFormatterCommand(formatter, filePath, projectRoot);
 
         if (cmd) {
           execFileSync(cmd.bin, cmd.args, {

tests/hooks/hooks.test.js

@@ -75,6 +75,20 @@ function cleanupTestDir(testDir) {
   fs.rmSync(testDir, { recursive: true, force: true });
 }
 
+function createCommandShim(binDir, name, logFile) {
+  const shimPath = path.join(binDir, name);
+  const script = `#!/bin/sh
+{
+  printf '%s\n' "$(basename \"$0\")"
+  for arg in "$@"; do
+    printf '%s\n' "$arg"
+  done
+} > ${JSON.stringify(logFile)}
+`;
+  fs.writeFileSync(shimPath, script, { mode: 0o755 });
+  return shimPath;
+}
+
 // Test suite
 async function runTests() {
   console.log('\n=== Testing Hook Scripts ===\n');
@@ -701,6 +715,64 @@ async function runTests() {
     assert.ok(result.stdout.includes('tool_input'), 'Should pass through original data');
   })) passed++; else failed++;
 
+  if (await asyncTest('uses CLAUDE_PACKAGE_MANAGER runner for formatter fallback', async () => {
+    const testDir = createTestDir();
+    const binDir = path.join(testDir, 'bin');
+    const logFile = path.join(testDir, 'pnpm.log');
+    fs.mkdirSync(binDir, { recursive: true });
+    createCommandShim(binDir, 'pnpm', logFile);
+
+    const testFile = path.join(testDir, 'src', 'example.ts');
+    fs.mkdirSync(path.dirname(testFile), { recursive: true });
+    fs.writeFileSync(path.join(testDir, 'package.json'), JSON.stringify({ name: 'pm-env-test' }));
+    fs.writeFileSync(path.join(testDir, '.prettierrc'), '{}');
+    fs.writeFileSync(testFile, 'const answer=42;\n');
+
+    try {
+      const stdinJson = JSON.stringify({ tool_input: { file_path: testFile } });
+      const result = await runScript(path.join(scriptsDir, 'post-edit-format.js'), stdinJson, {
+        CLAUDE_PACKAGE_MANAGER: 'pnpm',
+        PATH: `${binDir}${path.delimiter}${process.env.PATH || ''}`
+      });
+
+      assert.strictEqual(result.code, 0, 'Should exit 0 with pnpm fallback');
+      const logLines = fs.readFileSync(logFile, 'utf8').trim().split('\n');
+      assert.deepStrictEqual(logLines, ['pnpm', 'dlx', 'prettier', '--write', testFile]);
+    } finally {
+      cleanupTestDir(testDir);
+    }
+  })) passed++; else failed++;
+
+  if (await asyncTest('uses project package manager config for formatter fallback', async () => {
+    const testDir = createTestDir();
+    const binDir = path.join(testDir, 'bin');
+    const logFile = path.join(testDir, 'bunx.log');
+    fs.mkdirSync(binDir, { recursive: true });
+    fs.mkdirSync(path.join(testDir, '.claude'), { recursive: true });
+    createCommandShim(binDir, 'bunx', logFile);
+
+    const testFile = path.join(testDir, 'src', 'example.ts');
+    fs.mkdirSync(path.dirname(testFile), { recursive: true });
+    fs.writeFileSync(path.join(testDir, 'package.json'), JSON.stringify({ name: 'pm-project-test' }));
+    fs.writeFileSync(path.join(testDir, 'biome.json'), '{}');
+    fs.writeFileSync(path.join(testDir, '.claude', 'package-manager.json'), JSON.stringify({ packageManager: 'bun' }));
+    fs.writeFileSync(testFile, 'const answer=42;\n');
+
+    try {
+      const stdinJson = JSON.stringify({ tool_input: { file_path: testFile } });
+      const result = await runScript(path.join(scriptsDir, 'post-edit-format.js'), stdinJson, {
+        CLAUDE_PACKAGE_MANAGER: '',
+        PATH: `${binDir}${path.delimiter}${process.env.PATH || ''}`
+      });
+
+      assert.strictEqual(result.code, 0, 'Should exit 0 with project-config fallback');
+      const logLines = fs.readFileSync(logFile, 'utf8').trim().split('\n');
+      assert.deepStrictEqual(logLines, ['bunx', '@biomejs/biome', 'format', '--write', testFile]);
+    } finally {
+      cleanupTestDir(testDir);
+    }
+  })) passed++; else failed++;
+
   // post-edit-typecheck.js tests
   console.log('\npost-edit-typecheck.js:');