Fail commit if docs changed

src/docs.mts

@@ -1,11 +1,12 @@
 import { remark } from 'remark';
 import type { Code, Root } from 'mdast';
-import { readFileSync, writeFileSync, mkdirSync, copyFileSync } from 'fs';
+import { readFileSync, writeFileSync, mkdirSync, copyFileSync, existsSync } from 'fs';
 // @ts-ignore
 import flatmap from 'unist-util-flatmap';
 import { globby } from 'globby';
 import { join, dirname } from 'path';
 
+let fileChanged = false;
 // Possible Improvement: combine with lint-staged to only copy files that have changed
 const prepareOutFile = (file: string): string => {
   const outFile = join('docs', file.replace('src/docs/', ''));
@@ -13,6 +14,25 @@ const prepareOutFile = (file: string): string => {
   return outFile;
 };
 
+const verifyAndCopy = (file: string, content?: string) => {
+  const outFile = prepareOutFile(file);
+  const existing = existsSync(outFile) ? readFileSync(outFile) : Buffer.from('#NEW FILE#');
+  if (content !== undefined) {
+    if (!existing.equals(Buffer.from(content))) {
+      console.log(`Updating ${outFile}`);
+      writeFileSync(outFile, content);
+      fileChanged = true;
+    }
+  } else {
+    const newFile = readFileSync(file);
+    if (!existing.equals(newFile)) {
+      console.log(`Copying ${file} to ${outFile}`);
+      writeFileSync(outFile, newFile);
+      fileChanged = true;
+    }
+  }
+};
+
 const transform = (file: string) => {
   const doc = readFileSync(file, 'utf8');
   const ast: Root = remark.parse(doc);
@@ -29,8 +49,7 @@ const transform = (file: string) => {
   const transformed = `# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT. Please edit corresponding file in src/docs.\n${remark.stringify(
     out
   )}`;
-  const outFile = prepareOutFile(file);
-  writeFileSync(outFile, transformed);
+  verifyAndCopy(file, transformed);
 };
 
 (async () => {
@@ -38,6 +57,10 @@ const transform = (file: string) => {
   mdFiles.forEach(transform);
   const nonMDFiles = await globby(['src/docs/**', '!**/*.md']);
   nonMDFiles.forEach((file) => {
-    copyFileSync(file, prepareOutFile(file));
+    verifyAndCopy(file);
   });
+  if (fileChanged) {
+    console.log('Please commit the changes to the docs folder');
+    process.exit(1);
+  }
 })();