feat: Fail on fix (prettier#52)

README.md

@@ -92,6 +92,10 @@ When not in `staged` pre-commit mode, use this flag to compare changes with the
 
 Outputs the name of each file right before it is proccessed. This can be useful if Prettier throws an error and you can't identify which file is causing the problem.
 
+## `--fail-on-fix`
+
+Makes pretty-quick to exit with a non-zero exit code if any file is fixed. The intent is to abort the git commit.
+
 <!-- Undocumented = Unsupported :D
 
 ### `--config`

bin/pretty-quick.js

@@ -7,7 +7,12 @@ const mri = require('mri');
 
 const prettyQuick = require('..').default;
 
-const args = mri(process.argv.slice(2));
+const args = mri(process.argv.slice(2), {
+  boolean: ['fail-on-fix'],
+  default: { 'fail-on-fix': false },
+});
+
+const failOnFix = args['fail-on-fix'];
 
 let success = true;
 prettyQuick(
@@ -36,6 +41,9 @@ prettyQuick(
 
     onWriteFile: file => {
       console.log(`✍️  Fixing up ${chalk.bold(file)}.`);
+      if (failOnFix) {
+        success = false;
+      }
     },
 
     onExamineFile: file => {