feat: skip pre-commit if nothing is in the staging area (#79)

install.js

@@ -103,6 +103,10 @@ if (os.platform() === 'win32') {
 }
 
 const precommitContent = '#!/usr/bin/env bash' + os.EOL +
+  'if git diff --cached --quiet; then' + os.EOL +
+  '  echo "No staged changes detected, skipping pre-commit hook."' + os.EOL +
+  '  exit 0' + os.EOL +
+  'fi' + os.EOL +
   hookRelativeUnixPath + os.EOL +
   'RESULT=$?' + os.EOL +
   '[ $RESULT -ne 0 ] && exit 1' + os.EOL +

test.js

@@ -283,4 +283,27 @@ test('pre-commit', async (t) => {
       hook.run()
     })
   })
+
+  await t.test('skips pre-commit if no staged changes', (t) => {
+    const Hook = proxyquire('.', {
+      'node:child_process': {
+        execSync (command) {
+          if (command === 'git diff --cached --quiet') {
+            throw new Error('No staged changes')
+          }
+        }
+      }
+    })
+
+    const hook = new Hook(
+      function (code, lines) {
+        t.assert.strictEqual(code, 0, 'exit code should be 0')
+        t.assert.strictEqual(lines, undefined, 'lines should be undefined')
+      },
+      { ignorestatus: true }
+    )
+
+    hook.config.run = ['example-pass']
+    hook.run()
+  })
 })