Avoid loop rebuild in watch mode

src/bin/shared/generateKcGenTs.ts

@@ -3,6 +3,7 @@ import type { BuildContext } from "./buildContext";
 import { getThemeSrcDirPath } from "./getThemeSrcDirPath";
 import * as fs from "fs/promises";
 import { join as pathJoin } from "path";
+import { existsAsync } from "../tools/fs.existsAsync";
 
 export type BuildContextLike = {
     projectDirPath: string;
@@ -21,9 +22,13 @@ export async function generateKcGenTs(params: {
         projectDirPath: buildContext.projectDirPath
     });
 
-    await fs.writeFile(
+    const filePath = pathJoin(themeSrcDirPath, "kc.gen.ts");
-        pathJoin(themeSrcDirPath, "kc.gen.ts"),
+
-        Buffer.from(
+    const currentContent = (await existsAsync(filePath))
+        ? await fs.readFile(filePath)
+        : undefined;
+
+    const newContent = Buffer.from(
         [
             `/* prettier-ignore-start */`,
             ``,
@@ -56,6 +61,11 @@ export async function generateKcGenTs(params: {
             `/* prettier-ignore-end */`
         ].join("\n"),
         "utf8"
-        )
     );
+
+    if (currentContent !== undefined && currentContent.equals(newContent)) {
+        return;
+    }
+
+    await fs.writeFile(filePath, newContent);
 }