perf(studio): stream nitro repair progress over SSE and allow cancelling

src/lib/services/nitro-cleanup.ts

@@ -584,15 +584,28 @@ async function copyFileToDirs(
 	return errors;
 }
 
+export interface NitroRepairProgress {
+	completed: number;
+	total: number;
+	ok: number;
+	failed: number;
+	fileName?: string;
+	error?: string;
+}
+
 /**
  * Re-download broken .nitro bundles from the configured nitro sources. The
  * file stem matched an item in `items_base`, so the same classname candidates
  * used by repair-nitros.ts are tried; every downloaded bundle is validated
- * before it replaces the broken copies across all nitro directories.
+ * before it replaces the broken copies across all nitro directories. Bundles
+ * are repaired in parallel (pool of 6) and `onProgress` is called after each
+ * one settles, so a huge batch can be streamed to the client and cancelled.
  */
 export async function repairBrokenNitros(
 	fileNames: string[],
+	options: { onProgress?: (progress: NitroRepairProgress) => void } = {},
 ): Promise<NitroRepairResult> {
+	const { onProgress } = options;
 	const targets = await getFurniAssetWriteTargets();
 	const nitroDirs = dirsForKind(targets, "nitro");
 	let sources = (await listSources().catch(() => [] as never)).filter(
@@ -604,14 +617,23 @@ export async function repairBrokenNitros(
 	let failed = 0;
 	const errors: string[] = [];
 	const files: NitroRepairResult["files"] = [];
+	const uniqueFileNames = [...new Set(fileNames)];
+	const total = uniqueFileNames.length;
+	let completed = 0;
+	const finish = (fileName: string, ok: boolean, error?: string) => {
+		completed++;
+		if (ok) repaired++;
+		else failed++;
+		onProgress?.({ completed, total, ok: repaired, failed, fileName, error });
+	};
 
-	await runPool([...new Set(fileNames)], 6, async (rawName) => {
+	await runPool(uniqueFileNames, 6, async (rawName) => {
 		const fileName = String(rawName ?? "");
 		if (!NITRO_FILE_RE.test(fileName) || !fileName.endsWith(".nitro")) {
-			failed++;
 			const message = `Invalid nitro file name: ${fileName}`;
 			errors.push(message);
 			files.push({ fileName, ok: false, error: message });
+			finish(fileName, false, message);
 			return;
 		}
 		const name = fileName.slice(0, -".nitro".length);
@@ -648,16 +670,16 @@ export async function repairBrokenNitros(
 							nitroDirs,
 						);
 						if (writeErrors.length === 0) {
-							repaired++;
 							files.push({ fileName, ok: true });
+							finish(fileName, true);
 						} else {
-							failed++;
 							errors.push(...writeErrors);
 							files.push({
 								fileName,
 								ok: false,
 								error: writeErrors[0],
 							});
+							finish(fileName, false, writeErrors[0]);
 						}
 						return;
 					}
@@ -670,13 +692,14 @@ export async function repairBrokenNitros(
 				}
 			}
 		}
-		failed++;
+		const message = "could not re-obtain bundle from any nitro source";
 		errors.push(`could not re-obtain ${fileName} from any nitro source`);
 		files.push({
 			fileName,
 			ok: false,
-			error: "could not re-obtain bundle from any nitro source",
+			error: message,
 		});
+		finish(fileName, false, message);
 	});
 
 	return { repaired, failed, errors, files };