perf(studio): cache nitro scan, stream progress, virtualize cleanup list

src/lib/services/nitro-cleanup.test.ts

@@ -1,4 +1,5 @@
 // @vitest-environment node
+import { createHash } from "node:crypto";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 
 type AnyFn = (...args: any[]) => any;
@@ -130,6 +131,13 @@ function mockReaddir(byDir: Record<string, string[]>): void {
 	readdirFn.mockImplementation(async (dir: string) => byDir[dir] ?? []);
 }
 
+/** Replicates `dirNameSignature` in the service so cache fixtures match. */
+function dirSignature(names: string[]): string {
+	const hash = createHash("sha1");
+	for (const name of names) hash.update(name).update("\n");
+	return hash.digest("hex");
+}
+
 describe("scanFakeBrokenNitros", () => {
 	it("classifies fake (no matching item) and broken (unparseable) bundles", async () => {
 		mockReaddir({
@@ -233,6 +241,73 @@ describe("scanFakeBrokenNitros", () => {
 		expect(result.fake[0].size).toBe(900);
 		expect(result.fake[0].lastModified).toBe(2000);
 	});
+
+	it("serves results from the on-disk cache when directories are unchanged", async () => {
+		mockReaddir({
+			"/assets/nitro": ["chair.nitro", "ghost.nitro"],
+		});
+		const dirs = {
+			"nitro\u0000/assets/nitro": dirSignature(["chair.nitro", "ghost.nitro"]),
+			"swf\u0000/assets/swf": dirSignature([]),
+			"icon\u0000/assets/icons": dirSignature([]),
+		};
+		const cachedResult = {
+			fake: [
+				{
+					fileName: "ghost.nitro",
+					base: "ghost",
+					size: 500,
+					dirs: ["/assets/nitro"],
+					lastModified: 0,
+					error: undefined,
+				},
+			],
+			broken: [],
+			orphanedSwf: [],
+			orphanedIcon: [],
+			total: 4,
+		};
+		existsFn.mockImplementation((filePath: string) =>
+			filePath.includes("scan-cache.json"),
+		);
+		readFileFn.mockImplementation(async (filePath: string) => {
+			if (filePath.includes("scan-cache.json")) {
+				return JSON.stringify({ dirs, result: cachedResult });
+			}
+			return Buffer.from("nitro-data");
+		});
+
+		const result = await scanFakeBrokenNitros();
+
+		// `total: 4` could never come from a fresh scan of 2 files — the cache
+		// result came back verbatim, so classification was skipped entirely.
+		expect(result).toEqual(expect.objectContaining(cachedResult));
+		expect(result.cached).toBe(true);
+		expect(result.total).toBe(4);
+		expect(executeFn).not.toHaveBeenCalled();
+		expect(statFn).not.toHaveBeenCalled();
+		expect(readFileFn).toHaveBeenCalledTimes(1);
+		expect(writeFileFn).not.toHaveBeenCalled();
+	});
+
+	it("force bypasses the cache and re-validates the directories", async () => {
+		mockReaddir({
+			"/assets/nitro": ["chair.nitro", "ghost.nitro"],
+		});
+		// A matching-on-disk cache exists, but `force: true` ignores it.
+		existsFn.mockImplementation(() => true);
+		readFileFn.mockResolvedValue(Buffer.from("nitro-data"));
+		parseNitroBundle.mockReturnValue({});
+		statFn.mockImplementation(async () => ({ size: 512, mtimeMs: 0 }));
+
+		const result = await scanFakeBrokenNitros({ force: true });
+
+		expect(result.cached).toBeUndefined();
+		expect(result.fake.map((e) => e.fileName)).toEqual(["ghost.nitro"]);
+		expect(result.broken).toEqual([]);
+		expect(result.total).toBe(2);
+		expect(statFn).toHaveBeenCalled();
+	});
 });
 
 describe("deleteNitroCleanupFiles", () => {