refactor: executor protocol, fallback, debounce

docs/README.md

@@ -51,13 +51,13 @@
 только если темы нет в существующем документе; иначе обновляется источник
 истины.
 
-## Текущий baseline Q5
+## Текущий baseline Q6a
 
-На момент фиксации Q5:
+На момент фиксации Q6a:
 
 - production registry содержит 122 инструмента;
 - `pnpm --dir web check` проходит без ошибок и предупреждений;
-- `pnpm --dir web test` — 39 test files / 431 tests;
+- `pnpm --dir web test` — 41 test files / 445 tests;
 - `pnpm --dir web test:rules` — 4 test files / 74 tests;
 - `pnpm --dir web lint:all` — 0 errors и 0 i18n warnings; остаются 4 unused
   design tokens от token audit;

docs/plan-codebase-quality.md

@@ -1,10 +1,10 @@
 # План: линтеры, тесты и качество кодовой базы
 
-> Статус: **draft — Q0–Q5 готовы к ревью; Q6 — следующий этап**.
+> Статус: **draft — Q0–Q5 и Q6a готовы к ревью; Q6b — следующий этап**.
 >
 > Источник: `docs/backlog.md`, аудит конфигурации `web/`, e2e-тестов и
-> инфраструктурных скриптов. Q0–Q5 выполнены; Q6–Q8 выполняются отдельными
-> атомарными шагами.
+> инфраструктурных скриптов. Q0–Q5 и Q6a выполнены; Q6b–Q8 выполняются
+> отдельными атомарными шагами.
 >
 > Цель: сделать качество кодовой базы воспроизводимым, убрать ложную «зелёность»
 > проверок, стабилизировать тестовые контракты и только после этого расширять
@@ -189,30 +189,41 @@ Q6.
 - `ToolError` хранится как key/vars, переводится derived-значением при выводе и
   обновляется при смене локали. E2E использует независимый invalid pixel-count
   сценарий.
-- Resize/crop, generator, Reset и localization fixme сняты; Q6 начинает
-  расширение покрытия, а не исправление этих контрактов.
+- Resize/crop, generator, Reset и localization fixme сняты; Q6a расширяет
+  покрытие, не смешиваясь с исправлением этих контрактов.
 
 **Результат:** Q5 known issues закрыты и отражены в `docs/backlog.md` и
-`docs/checklist-manual-testing.md`; следующий этап — Q6.
+`docs/checklist-manual-testing.md`; Q6a выполнен, следующий этап — Q6b.
 
 ### Q6. Расширение unit и browser-покрытия
 
 **Оценка:** M–L. **Зависимости:** Q4, Q5.
 
-Сначала:
+#### Q6a. Executor protocol, fallback и debounce
 
-- executor и worker/fallback;
-- `FileResult`, ZIP и download;
-- `debounce` и auto-run;
+**Статус:** выполнен. Unit-тесты покрывают debounce, worker image/string/
+verdict/files protocol, `ToolError` transport, constructor/postMessage/onerror/
+malformed fallback, source-aware sanitization и DOM metadata. Browser smoke
+проверяет rapid auto-run и no-worker fallback; deferred transport fallback
+покрыт unit-тестами.
+
+- `execute(tool, ctx)` сохраняет публичный API; `createExecutor` и protocol
+  handler являются внутренними test seams.
+- `ToolError` не запускает direct retry повторно; transport/protocol failures
+  отключают worker и переходят в direct fallback.
+- DOM-зависимые registry entries помечены `domOnly`, поэтому зелёный smoke не
+  скрывает нормальный worker fallback.
+- `debounce` покрыт fake timers; E2E подтверждает последние значения при быстрых
+  последовательных изменениях генератора.
+
+#### Q6b–Q6f. Оставшиеся направления
+
+- `FileResult` → ZIP → download;
 - output MIME/quality;
 - malformed и special PNG fixtures: CRC, truncated, palette, 16-bit;
-- smoke всех типов инструментов из registry.
-
-Затем отдельно:
-
+- smoke всех типов инструментов из registry;
 - component-тесты `SchemaToolView`, `SchemaPreview` и schema fields;
-- browser matrix, mobile viewport и visual snapshots;
-- coverage thresholds.
+- browser matrix, mobile viewport, visual snapshots и coverage thresholds.
 
 Не применять один одинаковый smoke-сценарий к image-, text-, generator- и
 file-result-инструментам.

docs/testing-strategy.md

@@ -66,7 +66,7 @@ helpers, а не повторять raw-селекторы.
 
 `test.fixme` допускается только для зарегистрированной проблемы в backlog или
 checklist. В комментарии указывается ссылка на неё. После исправления тест и
-ссылка обновляются вместе; в текущем Q5 baseline активных fixme нет.
+ссылка обновляются вместе; в текущем Q6a baseline активных fixme нет.
 
 ## 6. Проверки
 

web/e2e/generators.spec.ts

@@ -16,12 +16,10 @@ test.describe("generators", () => {
 		await expect(resultImage(page)).toBeVisible();
 		await expect(page.getByRole("button", { name: "Generate" })).toHaveCount(0);
 
-		const firstSource = await resultImage(page).getAttribute("src");
 		await page.getByRole("spinbutton", { name: "Width" }).fill("32");
-		await expect(resultImage(page)).not.toHaveAttribute(
-			"src",
-			firstSource ?? "",
-		);
+		await page.getByRole("spinbutton", { name: "Height" }).fill("24");
+		await expect(resultImage(page)).toHaveJSProperty("naturalWidth", 32);
+		await expect(resultImage(page)).toHaveJSProperty("naturalHeight", 24);
 		await expectNoErrorAlert(page);
 		expectNoErrors(sink);
 	});

web/src/lib/core/debounce.test.ts

@@ -0,0 +1,38 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { debounce } from "./debounce";
+
+afterEach(() => {
+	vi.useRealTimers();
+});
+
+describe("debounce", () => {
+	it("coalesces calls until the deadline", () => {
+		vi.useFakeTimers();
+		const fn = vi.fn();
+		const debounced = debounce(fn, 200);
+
+		debounced();
+		vi.advanceTimersByTime(199);
+		debounced();
+		vi.advanceTimersByTime(199);
+		expect(fn).not.toHaveBeenCalled();
+
+		vi.advanceTimersByTime(1);
+		expect(fn).toHaveBeenCalledTimes(1);
+	});
+
+	it("cancels a pending call and can be scheduled again", () => {
+		vi.useFakeTimers();
+		const fn = vi.fn();
+		const debounced = debounce(fn, 200);
+
+		debounced();
+		debounced.cancel();
+		vi.advanceTimersByTime(200);
+		expect(fn).not.toHaveBeenCalled();
+
+		debounced();
+		vi.advanceTimersByTime(200);
+		expect(fn).toHaveBeenCalledTimes(1);
+	});
+});

web/src/lib/executor/executor.test.ts

@@ -0,0 +1,289 @@
+import { describe, expect, it, vi } from "vitest";
+import { ToolError } from "../core/errors";
+import {
+	createExecutor,
+	type ExecuteContext,
+	type WorkerFactory,
+	type WorkerLike,
+} from "./executor";
+import {
+	decodeWorkerResponse,
+	type WorkerRequest,
+	type WorkerResponse,
+} from "./protocol";
+import { handleWorkerRequest } from "./worker-handler";
+import { field, toolSchema, type Dimension } from "../registry-schema";
+import type { ToolEntry } from "../registry";
+
+class FakeWorker implements WorkerLike {
+	onmessage: ((event: MessageEvent<WorkerResponse>) => void) | null = null;
+	onerror: ((event: Event) => void) | null = null;
+	requests: WorkerRequest[] = [];
+	terminated = false;
+	throwOnPost = false;
+
+	postMessage(request: WorkerRequest): void {
+		this.requests.push(request);
+		if (this.throwOnPost) throw new Error("post failed");
+	}
+
+	respond(response: WorkerResponse): void {
+		this.onmessage?.({ data: response } as MessageEvent<WorkerResponse>);
+	}
+
+	fail(): void {
+		this.onerror?.(new Event("error"));
+	}
+
+	terminate(): void {
+		this.terminated = true;
+	}
+}
+
+function createFactory(throwOnPost = false): {
+	factory: WorkerFactory;
+	workers: FakeWorker[];
+} {
+	const workers: FakeWorker[] = [];
+	return {
+		factory: () => {
+			const worker = new FakeWorker();
+			worker.throwOnPost = throwOnPost;
+			workers.push(worker);
+			return worker;
+		},
+		workers,
+	};
+}
+
+const emptySchema = toolSchema<Record<string, never>>({});
+
+function makeTool(
+	run: ToolEntry["run"] = () => "direct",
+	overrides: Partial<ToolEntry> = {},
+): ToolEntry {
+	return {
+		id: "test-tool",
+		title: "Test tool",
+		description: "Test tool",
+		category: "analyze",
+		schema: emptySchema,
+		input: "none",
+		run,
+		...overrides,
+	};
+}
+
+function image(width = 2, height = 2): WorkerRequest["source"] {
+	return {
+		width,
+		height,
+		data: new Uint8ClampedArray(width * height * 4),
+	};
+}
+
+describe("createExecutor", () => {
+	it("validates required input before creating a worker", async () => {
+		const factory = vi.fn<WorkerFactory>();
+		const execute = createExecutor({ workerFactory: factory });
+		const imageTool = makeTool(vi.fn(), { input: "image" });
+		const textTool = makeTool(vi.fn(), { input: "text" });
+
+		await expect(execute(imageTool, { params: {} })).rejects.toMatchObject({
+			key: "errors.sourceRequired",
+		});
+		await expect(
+			execute(textTool, { params: {}, text: "  " }),
+		).rejects.toMatchObject({ key: "errors.textRequired" });
+		expect(factory).not.toHaveBeenCalled();
+	});
+
+	it("routes domOnly tools directly", async () => {
+		const { factory, workers } = createFactory();
+		const execute = createExecutor({ workerFactory: factory });
+		const run = vi.fn(() => "direct");
+		const tool = makeTool(run, { domOnly: true });
+
+		await expect(execute(tool, { params: {} })).resolves.toBe("direct");
+		expect(workers).toHaveLength(0);
+	});
+
+	it("passes source-aware sanitized params through the worker request", async () => {
+		const { factory, workers } = createFactory();
+		const execute = createExecutor({ workerFactory: factory });
+		const schema = toolSchema<{ size: Dimension }>({
+			size: field.dimension({
+				min: 1,
+				max: 100,
+				width: 1,
+				height: 1,
+				defaultFromSource: true,
+			}),
+		});
+		const tool = makeTool(() => "worker", { input: "image", schema });
+		const promise = execute(tool, {
+			params: { size: { width: 0, height: 0 } },
+			source: image(64, 48) as ExecuteContext["source"],
+		});
+		const worker = workers[0];
+		const request = worker.requests[0];
+		worker.respond({ id: request.id, ok: true, text: "worker" });
+
+		await expect(promise).resolves.toBe("worker");
+		expect(request.params).toEqual({ size: { width: 64, height: 48 } });
+	});
+
+	it("resolves concurrent worker responses by request id", async () => {
+		const { factory, workers } = createFactory();
+		const execute = createExecutor({ workerFactory: factory });
+		const tool = makeTool();
+		const first = execute(tool, { params: {} });
+		const second = execute(tool, { params: {} });
+		const worker = workers[0];
+		const [firstRequest, secondRequest] = worker.requests;
+
+		worker.respond({ id: secondRequest.id, ok: true, text: "second" });
+		worker.respond({ id: firstRequest.id, ok: true, text: "first" });
+
+		await expect(first).resolves.toBe("first");
+		await expect(second).resolves.toBe("second");
+	});
+
+	it("does not retry a worker ToolError directly", async () => {
+		const { factory, workers } = createFactory();
+		const execute = createExecutor({ workerFactory: factory });
+		const run = vi.fn(() => "direct");
+		const tool = makeTool(run);
+		const promise = execute(tool, { params: {} });
+		const worker = workers[0];
+		const request = worker.requests[0];
+		worker.respond({
+			id: request.id,
+			ok: false,
+			errorKey: "errors.badPixelToken",
+			errorVars: { value: "x" },
+		});
+
+		await expect(promise).rejects.toMatchObject({
+			key: "errors.badPixelToken",
+			vars: { value: "x" },
+		});
+		expect(run).not.toHaveBeenCalled();
+	});
+
+	it("falls back when worker construction fails", async () => {
+		const factory = vi.fn<WorkerFactory>(() => {
+			throw new Error("construction failed");
+		});
+		const execute = createExecutor({ workerFactory: factory });
+		const run = vi.fn(() => "direct");
+		const tool = makeTool(run);
+
+		await expect(execute(tool, { params: {} })).resolves.toBe("direct");
+		await expect(execute(tool, { params: {} })).resolves.toBe("direct");
+		expect(factory).toHaveBeenCalledTimes(1);
+		expect(run).toHaveBeenCalledTimes(2);
+	});
+
+	it("falls back after transport failures and disables the worker", async () => {
+		const { factory, workers } = createFactory(true);
+		const execute = createExecutor({ workerFactory: factory });
+		const run = vi.fn(() => "direct");
+		const tool = makeTool(run);
+
+		const postFailure = execute(tool, { params: {} });
+		await expect(postFailure).resolves.toBe("direct");
+		expect(workers[0].terminated).toBe(true);
+
+		await expect(execute(tool, { params: {} })).resolves.toBe("direct");
+		expect(workers).toHaveLength(1);
+	});
+
+	it("falls back after onerror and malformed responses", async () => {
+		for (const failure of ["error", "malformed"] as const) {
+			const { factory, workers } = createFactory();
+			const execute = createExecutor({ workerFactory: factory });
+			const tool = makeTool(() => "direct");
+			const promise = execute(tool, { params: {} });
+			const worker = workers[0];
+			if (failure === "error") {
+				worker.fail();
+			} else {
+				worker.respond({ id: worker.requests[0].id, ok: true });
+			}
+			await expect(promise).resolves.toBe("direct");
+			expect(worker.terminated).toBe(true);
+		}
+	});
+
+	it("decodes image, verdict, and files worker responses", () => {
+		const data = new Uint8ClampedArray([1, 2, 3, 4]);
+		const imageResult = decodeWorkerResponse({
+			id: 1,
+			ok: true,
+			width: 1,
+			height: 1,
+			data,
+		});
+		expect(imageResult).toMatchObject({ width: 1, height: 1 });
+
+		const verdict = decodeWorkerResponse({
+			id: 2,
+			ok: true,
+			text: "line",
+			textVars: { kb: "1" },
+		});
+		expect(verdict).toEqual({ key: "line", vars: { kb: "1" } });
+
+		const files = decodeWorkerResponse({
+			id: 3,
+			ok: true,
+			files: [{ name: "part.png", width: 1, height: 1, data }],
+		});
+		expect(files).toMatchObject({
+			files: [{ name: "part.png", image: { width: 1, height: 1 } }],
+		});
+	});
+});
+
+describe("handleWorkerRequest", () => {
+	it("serializes image results and preserves ToolError keys", async () => {
+		const imageResult = await handleWorkerRequest({
+			id: 1,
+			toolId: "flip-png",
+			params: {},
+			source: image(),
+		});
+		expect(imageResult.response).toMatchObject({
+			id: 1,
+			ok: true,
+			width: 2,
+			height: 2,
+		});
+		expect(imageResult.transfer).toHaveLength(1);
+
+		const errorResult = await handleWorkerRequest({
+			id: 2,
+			toolId: "bytes-to-png",
+			params: { width: 32 },
+			text: Array.from({ length: 132 }, () => "1").join(" "),
+		});
+		expect(errorResult.response).toMatchObject({
+			id: 2,
+			ok: false,
+			errorKey: "errors.pixelCountMismatch",
+			errorVars: { count: 33, width: 32 },
+		});
+	});
+
+	it("serializes FileResult transfers", async () => {
+		const result = await handleWorkerRequest({
+			id: 3,
+			toolId: "split-into-parts-png",
+			params: { columns: 2, rows: 2 },
+			source: image(),
+		});
+		expect(result.response).toMatchObject({ id: 3, ok: true });
+		expect(result.transfer).toHaveLength(4);
+	});
+});

web/src/lib/executor/executor.ts

@@ -1,173 +1,123 @@
-import { ToolError } from "$lib/core/errors";
-import type { PixelImage } from "$lib/core/types";
-import type { ToolContext, ToolEntry, ToolResult } from "$lib/registry";
-import { sanitizeSchemaParams } from "$lib/registry-schema";
+import { ToolError } from "../core/errors";
+import type { PixelImage } from "../core/types";
+import type { ToolContext, ToolEntry, ToolResult } from "../registry";
+import { sanitizeSchemaParams } from "../registry-schema";
+import {
+	decodeWorkerResponse,
+	isWorkerResponse,
+	type WorkerRequest,
+	type WorkerResponse,
+} from "./protocol";
 
-/** Вход единой точки исполнения. `source`/`text` — по контракту `tool.input`. */
 export type ExecuteContext = {
 	params: Record<string, unknown>;
 	source?: PixelImage;
 	text?: string;
 };
 
-/**
- * Единственная точка исполнения инструмента. Валидирует наличие входа по
- * `tool.input`, санитит параметры и запускает `tool.run`. Выбор места
- * исполнения (worker/поток) — внутренняя забота executor'а, диспетча методов
- * нет: у любого инструмента один `run(ctx)`.
- */
-export async function execute(
-	tool: ToolEntry,
-	ctx: ExecuteContext,
-): Promise<ToolResult> {
-	const params = sanitizeSchemaParams(tool.schema, ctx.params, {
-		source: ctx.source,
-	});
-	if (tool.input === "image" && !ctx.source) {
-		throw new ToolError("errors.sourceRequired");
-	}
-	if (tool.input === "text" && !ctx.text?.trim()) {
-		throw new ToolError("errors.textRequired");
-	}
-	return route(tool, { params, source: ctx.source, text: ctx.text });
+export type WorkerLike = {
+	postMessage(message: WorkerRequest): void;
+	terminate(): void;
+	onmessage: ((event: MessageEvent<WorkerResponse>) => void) | null;
+	onerror: ((event: Event) => void) | null;
+};
+
+export type WorkerFactory = () => WorkerLike;
+
+type PendingRequest = {
+	resolve: (result: ToolResult) => void;
+	reject: (error: unknown) => void;
+};
+
+function defaultWorkerFactory(): WorkerLike {
+	return new Worker(new URL("./executor.worker.ts", import.meta.url), {
+		type: "module",
+	}) as unknown as WorkerLike;
 }
 
-/**
- * Маршрутизация по способу исполнения. В worker уходит всё, кроме
- * domOnly-инструментов: даже текстовые вердикты могут быть тяжёлыми
- * (гистограммы, сложный анализ), поэтому ограничивать по типу результата
- * неверно. Ограничение одно — доступ к DOM, которого в worker нет.
- */
-async function route(
-	tool: ToolEntry,
-	ctx: ExecuteContext,
-): Promise<ToolResult> {
-	if (tool.domOnly || typeof Worker === "undefined") {
-		return await runDirect(tool, ctx);
-	}
-	const worker = ensureWorker();
-	if (worker === null) {
-		return await runDirect(tool, ctx);
-	}
-	try {
-		return await runInWorker(worker, tool, ctx);
-	} catch (workerError) {
-		disableWorker();
-		void workerError;
-		return await runDirect(tool, ctx);
-	}
-}
+export function createExecutor(
+	options: { workerFactory?: WorkerFactory } = {},
+): (tool: ToolEntry, ctx: ExecuteContext) => Promise<ToolResult> {
+	const workerFactory = options.workerFactory ?? defaultWorkerFactory;
+	let worker: WorkerLike | null = null;
+	let workerTried = false;
+	let nextRequestId = 1;
+	const pending = new Map<number, PendingRequest>();
 
-async function runDirect(
-	tool: ToolEntry,
-	ctx: ExecuteContext,
-): Promise<ToolResult> {
-	return await tool.run(ctx as ToolContext<Record<string, unknown>>);
-}
+	function failWorker(candidate: WorkerLike, error: unknown): void {
+		if (worker === candidate) worker = null;
+		candidate.terminate();
+		for (const [id, entry] of pending) {
+			pending.delete(id);
+			entry.reject(error);
+		}
+	}
 
-let worker: Worker | null = null;
-let workerTried = false;
-let nextRequestId = 1;
-const pending = new Map<
-	number,
-	{ resolve: (result: ToolResult) => void; reject: (e: Error) => void }
->();
-
-function ensureWorker(): Worker | null {
+	function ensureWorker(): WorkerLike | null {
 		if (workerTried) return worker;
 		workerTried = true;
+		let candidate: WorkerLike | undefined;
 		try {
-		const candidate = new Worker(
-			new URL("./executor.worker.ts", import.meta.url),
-			{
-				type: "module",
-			},
+			candidate = workerFactory();
+			candidate.onmessage = (event) => {
+				const payload: unknown = event.data;
+				if (!isWorkerResponse(payload)) {
+					failWorker(
+						candidate as WorkerLike,
+						new Error("Invalid worker response"),
 					);
-		candidate.onmessage = (event: MessageEvent) => {
-			const payload = event.data as {
-				id: number;
-				ok: boolean;
-				width?: number;
-				height?: number;
-				data?: Uint8ClampedArray;
-				files?: {
-					name: string;
-					width: number;
-					height: number;
-					data: Uint8ClampedArray;
-				}[];
-				text?: string;
-				textVars?: Record<string, string | number>;
-				error?: string;
-				errorKey?: string;
-				errorVars?: Record<string, string | number>;
-			};
+					return;
+				}
 				const entry = pending.get(payload.id);
 				if (!entry) return;
+				try {
+					const result = decodeWorkerResponse(payload);
 					pending.delete(payload.id);
-			if (payload.ok && payload.data && payload.width && payload.height) {
-				entry.resolve({
-					width: payload.width,
-					height: payload.height,
-					data: new Uint8ClampedArray(payload.data),
-				});
-			} else if (payload.ok && Array.isArray(payload.files)) {
-				entry.resolve({
-					files: payload.files.map((file) => ({
-						name: file.name,
-						image: {
-							width: file.width,
-							height: file.height,
-							data: new Uint8ClampedArray(file.data),
-						},
-					})),
-				});
-			} else if (payload.ok && typeof payload.text === "string") {
-				entry.resolve(
-					payload.textVars
-						? { key: payload.text, vars: payload.textVars }
-						: payload.text,
-				);
-			} else if (payload.errorKey) {
-				entry.reject(new ToolError(payload.errorKey, payload.errorVars));
+					entry.resolve(result);
+				} catch (error) {
+					if (error instanceof ToolError) {
+						pending.delete(payload.id);
+						entry.reject(error);
 					} else {
-				entry.reject(
-					payload.error
-						? new Error(payload.error)
-						: new ToolError("errors.workerFailed"),
-				);
+						failWorker(candidate as WorkerLike, error);
+					}
 				}
 			};
 			candidate.onerror = () => {
-			worker = null;
-			for (const entry of pending.values()) {
-				entry.reject(new ToolError("errors.workerUnavailable"));
-			}
-			pending.clear();
+				failWorker(candidate as WorkerLike, new Error("Worker error"));
 			};
 			worker = candidate;
-	} catch {
+			return candidate;
+		} catch (error) {
+			candidate?.terminate();
 			worker = null;
+			return null;
+		}
 	}
-	return worker;
-}
 
-function disableWorker(): void {
-	if (worker) {
-		worker.terminate();
-	}
+	function disableWorker(candidate: WorkerLike): void {
+		if (worker !== candidate) return;
 		worker = null;
-}
+		candidate.terminate();
+	}
 
-function runInWorker(
-	workerInstance: Worker,
+	async function runDirect(
 		tool: ToolEntry,
 		ctx: ExecuteContext,
-): Promise<ToolResult> {
+	): Promise<ToolResult> {
+		return await tool.run(ctx as ToolContext<Record<string, unknown>>);
+	}
+
+	function runInWorker(
+		candidate: WorkerLike,
+		tool: ToolEntry,
+		ctx: ExecuteContext,
+	): Promise<ToolResult> {
 		return new Promise((resolve, reject) => {
 			const id = nextRequestId++;
 			pending.set(id, { resolve, reject });
-		workerInstance.postMessage({
+			try {
+				candidate.postMessage({
 					id,
 					toolId: tool.id,
 					params: ctx.params,
@@ -180,5 +130,40 @@ function runInWorker(
 						: undefined,
 					text: ctx.text,
 				});
+			} catch (error) {
+				failWorker(candidate, error);
+			}
 		});
+	}
+
+	async function route(
+		tool: ToolEntry,
+		ctx: ExecuteContext,
+	): Promise<ToolResult> {
+		if (tool.domOnly) return await runDirect(tool, ctx);
+		const candidate = ensureWorker();
+		if (candidate === null) return await runDirect(tool, ctx);
+		try {
+			return await runInWorker(candidate, tool, ctx);
+		} catch (error) {
+			if (error instanceof ToolError) throw error;
+			disableWorker(candidate);
+			return await runDirect(tool, ctx);
+		}
+	}
+
+	return async (tool, ctx) => {
+		const params = sanitizeSchemaParams(tool.schema, ctx.params, {
+			source: ctx.source,
+		});
+		if (tool.input === "image" && !ctx.source) {
+			throw new ToolError("errors.sourceRequired");
+		}
+		if (tool.input === "text" && !ctx.text?.trim()) {
+			throw new ToolError("errors.textRequired");
+		}
+		return await route(tool, { ...ctx, params });
+	};
 }
+
+export const execute = createExecutor();

web/src/lib/executor/executor.worker.ts

@@ -1,113 +1,14 @@
 /// <reference lib="webworker" />
-import { ToolError } from "$lib/core/errors";
-import type { PixelImage } from "$lib/core/types";
-import { getTool } from "$lib/registry";
-import { sanitizeSchemaParams } from "$lib/registry-schema";
-
-type WorkerRequest = {
-	id: number;
-	toolId: string;
-	params: Record<string, unknown>;
-	source?: { width: number; height: number; data: Uint8ClampedArray };
-	text?: string;
-};
-
-type WorkerResponse =
-	| {
-			id: number;
-			ok: true;
-			width?: number;
-			height?: number;
-			data?: Uint8ClampedArray;
-			text?: string;
-			textVars?: Record<string, string | number>;
-			files?: WorkerImageFile[];
-	  }
-	| {
-			id: number;
-			ok: false;
-			error?: string;
-			errorKey?: string;
-			errorVars?: Record<string, string | number>;
-	  };
-
-type WorkerImageFile = {
-	name: string;
-	width: number;
-	height: number;
-	data: Uint8ClampedArray;
-};
+import { handleWorkerRequest } from "./worker-handler";
+import type { WorkerRequest, WorkerResponse } from "./protocol";
 
 self.onmessage = (event: MessageEvent<WorkerRequest>) => {
-	void handle(event.data);
+	void respond(event.data);
 };
 
-async function handle(request: WorkerRequest): Promise<void> {
-	try {
-		const tool = getTool(request.toolId);
-		if (!tool?.run) {
-			throw new ToolError("errors.noImageRun");
-		}
-		const source: PixelImage | undefined = request.source
-			? {
-					width: request.source.width,
-					height: request.source.height,
-					data: new Uint8ClampedArray(request.source.data),
-				}
-			: undefined;
-		const output = await tool.run({
-			params: sanitizeSchemaParams(tool.schema, request.params, { source }),
-			source,
-			text: request.text,
-		});
-		if (typeof output === "string") {
-			(self as unknown as Worker).postMessage({
-				id: request.id,
-				ok: true,
-				text: output,
-			} satisfies WorkerResponse);
-			return;
-		}
-		if ("key" in output) {
-			(self as unknown as Worker).postMessage({
-				id: request.id,
-				ok: true,
-				text: output.key,
-				textVars: output.vars,
-			} satisfies WorkerResponse);
-			return;
-		}
-		if ("files" in output) {
-			const files = output.files.map((file) => ({
-				name: file.name,
-				width: file.image.width,
-				height: file.image.height,
-				data: file.image.data,
-			}));
-			(self as unknown as Worker).postMessage(
-				{ id: request.id, ok: true, files } satisfies WorkerResponse,
-				files.map((file) => file.data.buffer),
-			);
-			return;
-		}
-		(self as unknown as Worker).postMessage(
-			{
-				id: request.id,
-				ok: true,
-				width: output.width,
-				height: output.height,
-				data: output.data,
-			} satisfies WorkerResponse,
-			[output.data.buffer],
-		);
-	} catch (e) {
-		const toolError = e instanceof ToolError ? e : undefined;
-		(self as unknown as Worker).postMessage({
-			id: request.id,
-			ok: false,
-			error: e instanceof Error ? e.message : String(e),
-			errorKey: toolError?.key,
-			errorVars: toolError?.vars,
-		} satisfies WorkerResponse);
-	}
+async function respond(request: WorkerRequest): Promise<void> {
+	const result = await handleWorkerRequest(request);
+	(self as unknown as Worker).postMessage(result.response, result.transfer);
 }
+
+export type { WorkerRequest, WorkerResponse };

web/src/lib/executor/protocol.ts

@@ -0,0 +1,161 @@
+import { ToolError, type ErrorVars } from "../core/errors";
+import type { FileResult, ToolResult } from "../registry";
+
+export type WorkerImage = {
+	width: number;
+	height: number;
+	data: Uint8ClampedArray;
+};
+
+export type WorkerFile = {
+	name: string;
+	width: number;
+	height: number;
+	data: Uint8ClampedArray;
+};
+
+export type WorkerRequest = {
+	id: number;
+	toolId: string;
+	params: Record<string, unknown>;
+	source?: WorkerImage;
+	text?: string;
+};
+
+export type WorkerResponse =
+	| {
+			id: number;
+			ok: true;
+			width?: number;
+			height?: number;
+			data?: Uint8ClampedArray;
+			text?: string;
+			textVars?: ErrorVars;
+			files?: WorkerFile[];
+	  }
+	| {
+			id: number;
+			ok: false;
+			error?: string;
+			errorKey?: string;
+			errorVars?: ErrorVars;
+	  };
+
+export type WorkerResult = {
+	response: WorkerResponse;
+	transfer: Transferable[];
+};
+
+function transferables(...values: Uint8ClampedArray[]): Transferable[] {
+	return values.map((value) => value.buffer as ArrayBuffer);
+}
+
+export function isWorkerResponse(value: unknown): value is WorkerResponse {
+	if (typeof value !== "object" || value === null) return false;
+	const candidate = value as { id?: unknown; ok?: unknown };
+	return typeof candidate.id === "number" && typeof candidate.ok === "boolean";
+}
+
+export function encodeWorkerResponse(
+	id: number,
+	result: ToolResult,
+): WorkerResult {
+	if (typeof result === "string") {
+		return { response: { id, ok: true, text: result }, transfer: [] };
+	}
+	if ("key" in result) {
+		return {
+			response: { id, ok: true, text: result.key, textVars: result.vars },
+			transfer: [],
+		};
+	}
+	if ("files" in result) {
+		const files = result.files.map((file) => ({
+			name: file.name,
+			width: file.image.width,
+			height: file.image.height,
+			data: file.image.data,
+		}));
+		return {
+			response: { id, ok: true, files },
+			transfer: transferables(...files.map((file) => file.data)),
+		};
+	}
+	return {
+		response: {
+			id,
+			ok: true,
+			width: result.width,
+			height: result.height,
+			data: result.data,
+		},
+		transfer: transferables(result.data),
+	};
+}
+
+export function encodeWorkerError(id: number, error: unknown): WorkerResult {
+	const toolError = error instanceof ToolError ? error : undefined;
+	return {
+		response: {
+			id,
+			ok: false,
+			error: error instanceof Error ? error.message : String(error),
+			errorKey: toolError?.key,
+			errorVars: toolError?.vars,
+		},
+		transfer: [],
+	};
+}
+
+function isWorkerFile(value: WorkerFile): boolean {
+	return (
+		typeof value.name === "string" &&
+		typeof value.width === "number" &&
+		typeof value.height === "number" &&
+		value.data instanceof Uint8ClampedArray
+	);
+}
+
+export function decodeWorkerResponse(payload: WorkerResponse): ToolResult {
+	if (payload.ok) {
+		if (
+			typeof payload.width === "number" &&
+			typeof payload.height === "number" &&
+			payload.data instanceof Uint8ClampedArray
+		) {
+			return {
+				width: payload.width,
+				height: payload.height,
+				data: new Uint8ClampedArray(payload.data),
+			};
+		}
+		if (Array.isArray(payload.files)) {
+			if (!payload.files.every(isWorkerFile)) {
+				throw new Error("Invalid worker response");
+			}
+			return {
+				files: payload.files.map((file) => ({
+					name: file.name,
+					image: {
+						width: file.width,
+						height: file.height,
+						data: new Uint8ClampedArray(file.data),
+					},
+				})),
+			} satisfies FileResult;
+		}
+		if (typeof payload.text === "string") {
+			return payload.textVars
+				? { key: payload.text, vars: payload.textVars }
+				: payload.text;
+		}
+		throw new Error("Invalid worker response");
+	}
+	if (payload.errorKey) {
+		throw new ToolError(payload.errorKey, payload.errorVars);
+	}
+	if (payload.error?.startsWith("errors.")) {
+		throw new ToolError(payload.error);
+	}
+	throw new Error(payload.error ?? "Invalid worker response");
+}

web/src/lib/executor/worker-handler.ts

@@ -0,0 +1,36 @@
+import { ToolError } from "../core/errors";
+import type { PixelImage } from "../core/types";
+import { getTool } from "../registry";
+import { sanitizeSchemaParams } from "../registry-schema";
+import {
+	encodeWorkerError,
+	encodeWorkerResponse,
+	type WorkerRequest,
+	type WorkerResult,
+} from "./protocol";
+
+export async function handleWorkerRequest(
+	request: WorkerRequest,
+): Promise<WorkerResult> {
+	try {
+		const tool = getTool(request.toolId);
+		if (!tool?.run) {
+			throw new ToolError("errors.noImageRun");
+		}
+		const source: PixelImage | undefined = request.source
+			? {
+					width: request.source.width,
+					height: request.source.height,
+					data: new Uint8ClampedArray(request.source.data),
+				}
+			: undefined;
+		const output = await tool.run({
+			params: sanitizeSchemaParams(tool.schema, request.params, { source }),
+			source,
+			text: request.text,
+		});
+		return encodeWorkerResponse(request.id, output);
+	} catch (error) {
+		return encodeWorkerError(request.id, error);
+	}
+}

web/src/lib/registry/convert.ts

@@ -105,6 +105,7 @@ const pngToBase64: ToolEntry<NoParams> = {
 	schema: emptySchema,
 	input: "image",
 	result: "text",
+	domOnly: true,
 	run: imgTool((img) => toBase64(img)),
 };
 
@@ -117,6 +118,7 @@ const pngToDataUri: ToolEntry<NoParams> = {
 	schema: emptySchema,
 	input: "image",
 	result: "text",
+	domOnly: true,
 	run: imgTool((img) => toDataUrl(img)),
 };
 
@@ -163,6 +165,7 @@ const base64ToPng: ToolEntry<NoParams> = {
 	category: "convert",
 	schema: emptySchema,
 	input: "text",
+	domOnly: true,
 	run: textGen((text) => decodeBytes(base64ToBytes(stripDataUri(text)))),
 };
 
@@ -173,6 +176,7 @@ const dataUriToPng: ToolEntry<NoParams> = {
 	category: "convert",
 	schema: emptySchema,
 	input: "text",
+	domOnly: true,
 	run: textGen((text) => decodeBytes(base64ToBytes(stripDataUri(text)))),
 };
 

web/src/lib/registry/filters.ts

@@ -253,6 +253,7 @@ const jpegArtifacts: ToolEntry<JpegArtifactsParams> = {
 	category: "filters",
 	schema: jpegArtifactsSchema,
 	input: "image",
+	domOnly: true,
 	run: imgTool((img, p) => jpegRoundtrip(img, p.quality)),
 };
 

web/src/lib/registry/generate.ts

@@ -487,6 +487,7 @@ const placeholder: ToolEntry<PlaceholderParams> = {
 	category: "generate",
 	schema: placeholderSchema,
 	input: "none",
+	domOnly: true,
 	run: genTool((p) => {
 		const w = Math.trunc(p.size.width);
 		const h = Math.trunc(p.size.height);

web/src/lib/registry/registry.test.ts

@@ -65,6 +65,19 @@ describe("registry-new (переведённые инструменты)", () =>
 		}
 	});
 
+	it("DOM-dependent tools bypass the worker", () => {
+		for (const id of [
+			"png-to-base64",
+			"png-to-data-uri",
+			"base64-to-png",
+			"data-uri-to-png",
+			"jpeg-artifacts-png",
+			"placeholder-png",
+		]) {
+			expect(TOOLS.find((tool) => tool.id === id)?.domOnly, id).toBe(true);
+		}
+	});
+
 	it("source-aware dimension defaults применяются только к image tools", () => {
 		for (const tool of TOOLS) {
 			for (const field of Object.values(tool.schema.fields)) {