fix(housekeeping): harden readonly schema facade

src/features/housekeeping/foundation/commands/dispatcher.test.ts

@@ -274,6 +274,75 @@ describe("dispatchHousekeepingCommand", () => {
 		expect(valid).toMatchObject({ ok: true });
 		expect(executions).toBe(1);
 	});
+	it("rejects public error callbacks before they can weaken dispatcher validation", async () => {
+		const commandId = "system.dispatch.callback-schema-mutation";
+		let executions = 0;
+		register(
+			baseCommand(commandId, {
+				input: z.object({ value: z.string().min(3) }),
+				execute: async (context) => {
+					executions += 1;
+					return ok(null, context.correlationId);
+				},
+			}),
+		);
+		const registered = getHousekeepingCommand(commandId);
+		if (!registered) throw new Error("registered command missing");
+
+		let callbackCalls = 0;
+		let capturedInstance: unknown;
+		let attackError: unknown;
+		try {
+			registered.input.safeParse(
+				{ value: "x" },
+				{
+					error: (issue) => {
+						callbackCalls += 1;
+						capturedInstance = issue.inst;
+						if (issue.inst) {
+							const internal = issue.inst._zod as {
+								def?: { minimum?: number };
+							};
+							if (typeof internal.def?.minimum === "number") {
+								internal.def.minimum = 0;
+							}
+						}
+						return "forged validation error";
+					},
+				},
+			);
+		} catch (error) {
+			attackError = error;
+		}
+
+		const forged = await dispatchHousekeepingCommand(
+			{ commandId, input: { value: "x" } },
+			dependencies(),
+		);
+		const valid = await dispatchHousekeepingCommand(
+			{ commandId, input: { value: "valid" } },
+			dependencies(),
+		);
+
+		expect({
+			attackError:
+				attackError instanceof TypeError ? attackError.message : undefined,
+			callbackCalls,
+			capturedInstance,
+			forgedOk: forged.ok,
+			forgedCode: forged.ok ? undefined : forged.error.code,
+			validOk: valid.ok,
+			executions,
+		}).toEqual({
+			attackError: "callback-bearing schema arguments are not supported",
+			callbackCalls: 0,
+			capturedInstance: undefined,
+			forgedOk: false,
+			forgedCode: "VALIDATION",
+			validOk: true,
+			executions: 1,
+		});
+	});
 	it("rejects a missing required reason before the command can execute", async () => {
 		let executed = false;
 		const audit = auditRecorder();

src/features/housekeeping/foundation/commands/registry.test.ts

@@ -71,6 +71,45 @@ function attemptMutation(mutate: () => void): void {
 	}
 }
 
+function mutationWasRejected(mutate: () => void): boolean {
+	try {
+		mutate();
+		return false;
+	} catch {
+		return true;
+	}
+}
+
+const unsafeSchemaCallbackMessage =
+	"callback-bearing schema arguments are not supported";
+
+const callbackOptionMethodNames = [
+	"parse",
+	"safeParse",
+	"parseAsync",
+	"safeParseAsync",
+	"spa",
+	"encode",
+	"decode",
+	"encodeAsync",
+	"decodeAsync",
+	"safeEncode",
+	"safeDecode",
+	"safeEncodeAsync",
+	"safeDecodeAsync",
+] as const;
+
+function attemptMinimumMutation(instance: unknown): void {
+	if (typeof instance !== "object" || instance === null) return;
+	const internal = Reflect.get(instance, "_zod") as
+		| { def?: { minimum?: number } }
+		| undefined;
+	if (typeof internal?.def?.minimum !== "number") return;
+	attemptMutation(() => {
+		if (internal.def) internal.def.minimum = 0;
+	});
+}
+
 describe("housekeeping command registry", () => {
 	it("returns the validated snapshot registered under its global ID", () => {
 		const registered = command("people.registry.lookup");
@@ -506,6 +545,337 @@ describe("housekeeping command registry", () => {
 			true,
 		);
 	});
+	it.each(callbackOptionMethodNames)(
+		"rejects callback-bearing %s options before private issue nodes are exposed",
+		async (methodName) => {
+			const input = z.object({ value: z.string().min(3) });
+			const id = `people.registry.callback-${methodName.toLowerCase()}`;
+			registerHousekeepingCommand({
+				...command(id),
+				input,
+				execute: async (context) => ok({ id: 1 }, context.correlationId),
+			} as HousekeepingCommand<z.output<typeof input>, { id: number }>);
+			const registered = getHousekeepingCommand(id);
+			if (!registered) throw new Error("registered command missing");
+
+			let callbackCalls = 0;
+			let capturedInstance: unknown;
+			const errorCallback = (issue: unknown): string => {
+				callbackCalls += 1;
+				capturedInstance = Reflect.get(issue as object, "inst");
+				attemptMinimumMutation(capturedInstance);
+				return "forged validation error";
+			};
+			const method = Reflect.get(registered.input, methodName);
+			if (typeof method !== "function") {
+				throw new Error(`public schema method missing: ${methodName}`);
+			}
+			const attack = Promise.resolve().then(() =>
+				Reflect.apply(method, registered.input, [
+					{ value: "x" },
+					{ error: errorCallback },
+				]),
+			);
+
+			await expect(attack).rejects.toThrow(unsafeSchemaCallbackMessage);
+			expect(callbackCalls).toBe(0);
+			expect(capturedInstance).toBeUndefined();
+			expect(registered.input.safeParse({ value: "x" }).success).toBe(false);
+			expect(registered.input.safeParse({ value: "valid" }).success).toBe(true);
+		},
+	);
+
+	it("rejects JSON-schema overrides before private schema or check nodes are exposed", () => {
+		const input = z.object({ value: z.string().min(3) });
+		const id = "people.registry.callback-json-schema";
+		registerHousekeepingCommand({
+			...command(id),
+			input,
+			execute: async (context) => ok({ id: 1 }, context.correlationId),
+		} as HousekeepingCommand<z.output<typeof input>, { id: number }>);
+		const registered = getHousekeepingCommand(id);
+		if (!registered) throw new Error("registered command missing");
+
+		let callbackCalls = 0;
+		let capturedSchema: unknown;
+		let attackError: unknown;
+		try {
+			registered.input.toJSONSchema({
+				override: ({ zodSchema }) => {
+					callbackCalls += 1;
+					capturedSchema = zodSchema;
+					const checks = (zodSchema._zod.def as { checks?: unknown[] }).checks;
+					if (checks?.[0]) attemptMinimumMutation(checks[0]);
+				},
+			});
+		} catch (error) {
+			attackError = error;
+		}
+
+		expect({
+			attackError:
+				attackError instanceof TypeError ? attackError.message : undefined,
+			callbackCalls,
+			capturedSchema,
+			shortValueAccepted: registered.input.safeParse({ value: "x" }).success,
+			validValueAccepted: registered.input.safeParse({ value: "valid" })
+				.success,
+		}).toEqual({
+			attackError: unsafeSchemaCallbackMessage,
+			callbackCalls: 0,
+			capturedSchema: undefined,
+			shortValueAccepted: false,
+			validValueAccepted: true,
+		});
+	});
+
+	it("rejects an error callback concealed behind an option Proxy", () => {
+		const input = z.object({ value: z.string().min(3) });
+		const id = "people.registry.callback-proxy-options";
+		registerHousekeepingCommand({
+			...command(id),
+			input,
+			execute: async (context) => ok({ id: 1 }, context.correlationId),
+		} as HousekeepingCommand<z.output<typeof input>, { id: number }>);
+		const registered = getHousekeepingCommand(id);
+		if (!registered) throw new Error("registered command missing");
+
+		let callbackCalls = 0;
+		let capturedInstance: unknown;
+		const errorCallback = (issue: unknown): string => {
+			callbackCalls += 1;
+			capturedInstance = Reflect.get(issue as object, "inst");
+			attemptMinimumMutation(capturedInstance);
+			return "forged validation error";
+		};
+		const concealedOptions = new Proxy(
+			{},
+			{
+				get: (_target, property) =>
+					property === "error" ? errorCallback : undefined,
+				getOwnPropertyDescriptor: () => undefined,
+				ownKeys: () => [],
+			},
+		);
+		let attackError: unknown;
+		try {
+			registered.input.safeParse({ value: "x" }, concealedOptions as never);
+		} catch (error) {
+			attackError = error;
+		}
+
+		expect({
+			attackError:
+				attackError instanceof TypeError ? attackError.message : undefined,
+			callbackCalls,
+			capturedInstance,
+			shortValueAccepted: registered.input.safeParse({ value: "x" }).success,
+			validValueAccepted: registered.input.safeParse({ value: "valid" })
+				.success,
+		}).toEqual({
+			attackError: unsafeSchemaCallbackMessage,
+			callbackCalls: 0,
+			capturedInstance: undefined,
+			shortValueAccepted: false,
+			validValueAccepted: true,
+		});
+	});
+
+	it("keeps callback-free sync and async parsing available", async () => {
+		const input = z.object({ value: z.string().min(3) });
+		const id = "people.registry.callback-free-parse";
+		registerHousekeepingCommand({
+			...command(id),
+			input,
+			execute: async (context) => ok({ id: 1 }, context.correlationId),
+		} as HousekeepingCommand<z.output<typeof input>, { id: number }>);
+		const registered = getHousekeepingCommand(id);
+		if (!registered) throw new Error("registered command missing");
+
+		expect(
+			registered.input.parse({ value: "valid" }, { jitless: true }),
+		).toEqual({ value: "valid" });
+		expect(
+			registered.input.safeParse({ value: "valid" }, { reportInput: true }),
+		).toMatchObject({ success: true, data: { value: "valid" } });
+		await expect(
+			registered.input.parseAsync({ value: "valid" }, { jitless: true }),
+		).resolves.toEqual({ value: "valid" });
+		await expect(
+			registered.input.safeParseAsync({ value: "x" }, { reportInput: true }),
+		).resolves.toMatchObject({ success: false });
+	});
+
+	it("exposes detached Map, Set, and Date values as behaviorally readonly views", () => {
+		const sourceMap = new Map<string, { count: number }>([
+			["registered", { count: 1 }],
+		]);
+		const sourceSet = new Set(["registered"]);
+		const sourceDate = new Date("2026-08-26T12:34:56.000Z");
+		const input = z.object({ value: z.string() });
+		Object.assign(input.def, {
+			exposedMap: sourceMap,
+			exposedSet: sourceSet,
+			exposedDate: sourceDate,
+		});
+		const id = "people.registry.readonly-builtins";
+		registerHousekeepingCommand({
+			...command(id),
+			input,
+			execute: async (context) => ok({ id: 1 }, context.correlationId),
+		} as HousekeepingCommand<z.output<typeof input>, { id: number }>);
+		const registered = getHousekeepingCommand(id);
+		if (!registered) throw new Error("registered command missing");
+		const publicDefinition = registered.input
+			.def as typeof registered.input.def & {
+			exposedMap: ReadonlyMap<string, { count: number }>;
+			exposedSet: ReadonlySet<string>;
+			exposedDate: Date;
+		};
+		const publicMap = publicDefinition.exposedMap;
+		const publicSet = publicDefinition.exposedSet;
+		const publicDate = publicDefinition.exposedDate;
+
+		sourceMap.set("caller-late", { count: 2 });
+		sourceSet.add("caller-late");
+		sourceDate.setTime(0);
+		const mapForEachReceivers: unknown[] = [];
+		const mapEntries: Array<[string, number]> = [];
+		publicMap.forEach((value, key, collection) => {
+			mapEntries.push([key, value.count]);
+			mapForEachReceivers.push(collection);
+		});
+		const setForEachReceivers: unknown[] = [];
+		const setEntries: string[] = [];
+		publicSet.forEach((value, duplicate, collection) => {
+			expect(duplicate).toBe(value);
+			setEntries.push(value);
+			setForEachReceivers.push(collection);
+		});
+		const dateIsoBefore = publicDate.toISOString();
+
+		const mapEscape = Symbol("map-escape");
+		const setEscape = Symbol("set-escape");
+		const dateEscape = Symbol("date-escape");
+		Object.defineProperty(Map.prototype, mapEscape, {
+			configurable: true,
+			value(this: Map<unknown, unknown>): Map<unknown, unknown> {
+				return this;
+			},
+		});
+		Object.defineProperty(Set.prototype, setEscape, {
+			configurable: true,
+			value(this: Set<unknown>): Set<unknown> {
+				return this;
+			},
+		});
+		Object.defineProperty(Date.prototype, dateEscape, {
+			configurable: true,
+			value(this: Date): Date {
+				return this;
+			},
+		});
+		let escapedMap: unknown;
+		let escapedSet: unknown;
+		let escapedDate: unknown;
+		try {
+			const mapMethod = Reflect.get(publicMap, mapEscape);
+			const setMethod = Reflect.get(publicSet, setEscape);
+			const dateMethod = Reflect.get(publicDate, dateEscape);
+			if (
+				typeof mapMethod !== "function" ||
+				typeof setMethod !== "function" ||
+				typeof dateMethod !== "function"
+			) {
+				throw new Error("dynamic builtin method missing");
+			}
+			escapedMap = Reflect.apply(mapMethod, publicMap, []);
+			escapedSet = Reflect.apply(setMethod, publicSet, []);
+			escapedDate = Reflect.apply(dateMethod, publicDate, []);
+		} finally {
+			Reflect.deleteProperty(Map.prototype, mapEscape);
+			Reflect.deleteProperty(Set.prototype, setEscape);
+			Reflect.deleteProperty(Date.prototype, dateEscape);
+		}
+		const escapeMutationResults = [
+			mutationWasRejected(() =>
+				(escapedMap as Map<string, { count: number }>).set("escaped-forged", {
+					count: 11,
+				}),
+			),
+			mutationWasRejected(() =>
+				(escapedSet as Set<string>).add("escaped-forged"),
+			),
+			mutationWasRejected(() => (escapedDate as Date).setTime(0)),
+		];
+
+		const mapMutationResults = [
+			mutationWasRejected(() =>
+				(publicMap as Map<string, { count: number }>).set("forged", {
+					count: 9,
+				}),
+			),
+			mutationWasRejected(() =>
+				(publicMap as Map<string, { count: number }>).delete("registered"),
+			),
+			mutationWasRejected(() =>
+				(publicMap as Map<string, { count: number }>).clear(),
+			),
+			mutationWasRejected(() =>
+				Map.prototype.set.call(
+					publicMap as Map<string, { count: number }>,
+					"prototype-forged",
+					{ count: 10 },
+				),
+			),
+		];
+		const setMutationResults = [
+			mutationWasRejected(() => (publicSet as Set<string>).add("forged")),
+			mutationWasRejected(() =>
+				(publicSet as Set<string>).delete("registered"),
+			),
+			mutationWasRejected(() => (publicSet as Set<string>).clear()),
+			mutationWasRejected(() =>
+				Set.prototype.add.call(publicSet as Set<string>, "prototype-forged"),
+			),
+		];
+		const dateMutationResults = Object.getOwnPropertyNames(Date.prototype)
+			.filter((property) => property.startsWith("set"))
+			.map((property) =>
+				mutationWasRejected(() => {
+					const method = Reflect.get(publicDate, property);
+					if (typeof method !== "function") {
+						throw new TypeError(`date mutator unavailable: ${property}`);
+					}
+					Reflect.apply(method, publicDate, [0]);
+				}),
+			);
+		dateMutationResults.push(
+			mutationWasRejected(() => Date.prototype.setTime.call(publicDate, 0)),
+		);
+		let dateIsoAfter: string | undefined;
+		try {
+			dateIsoAfter = publicDate.toISOString();
+		} catch {
+			dateIsoAfter = undefined;
+		}
+
+		expect(dateMutationResults.length).toBeGreaterThan(1);
+		expect(dateMutationResults.every(Boolean)).toBe(true);
+		expect(escapeMutationResults).toEqual([true, true, true]);
+		expect(mapEntries).toEqual([["registered", 1]]);
+		expect(mapForEachReceivers).toHaveLength(1);
+		expect(mapForEachReceivers[0]).toBe(publicMap);
+		expect(mapMutationResults).toEqual([true, true, true, true]);
+		expect([...publicMap.entries()]).toEqual([["registered", { count: 1 }]]);
+		expect(setEntries).toEqual(["registered"]);
+		expect(setForEachReceivers).toHaveLength(1);
+		expect(setForEachReceivers[0]).toBe(publicSet);
+		expect(setMutationResults).toEqual([true, true, true, true]);
+		expect([...publicSet]).toEqual(["registered"]);
+		expect(dateIsoBefore).toBe("2026-08-26T12:34:56.000Z");
+		expect(dateIsoAfter).toBe("2026-08-26T12:34:56.000Z");
+	});
 	it("seals the global registry after deterministic bootstrap", () => {
 		sealHousekeepingCommandRegistry();
 

src/features/housekeeping/foundation/commands/registry.ts

@@ -24,7 +24,8 @@ export interface HousekeepingCommand<I, O> {
 	/**
 	 * Registration snapshots structural/built-in Zod graphs and resolvable lazy
 	 * edges. Stateful custom refinements, transforms, preprocessors, and other
-	 * executable schema callbacks are rejected.
+	 * executable schema callbacks are rejected. The registered public facade
+	 * accepts callback-free parse, codec, and JSON-schema options only.
 	 */
 	readonly input: z.ZodType<I>;
 	readonly requiresReason: boolean;
@@ -355,9 +356,53 @@ function isZodInternalNode(value: object): value is ZodInternalNode {
 	);
 }
 
+type ReadonlyIntrinsicMethod = (...args: never[]) => unknown;
+
+const MAP_READ_METHODS = new Map<PropertyKey, ReadonlyIntrinsicMethod>([
+	["get", Map.prototype.get as unknown as ReadonlyIntrinsicMethod],
+	["has", Map.prototype.has as unknown as ReadonlyIntrinsicMethod],
+	["entries", Map.prototype.entries as unknown as ReadonlyIntrinsicMethod],
+	["keys", Map.prototype.keys as unknown as ReadonlyIntrinsicMethod],
+	["values", Map.prototype.values as unknown as ReadonlyIntrinsicMethod],
+	[
+		Symbol.iterator,
+		Map.prototype[Symbol.iterator] as unknown as ReadonlyIntrinsicMethod,
+	],
+]);
+const MAP_SIZE_GETTER = Object.getOwnPropertyDescriptor(Map.prototype, "size")
+	?.get as ReadonlyIntrinsicMethod | undefined;
+const SET_READ_METHODS = new Map<PropertyKey, ReadonlyIntrinsicMethod>([
+	["has", Set.prototype.has as unknown as ReadonlyIntrinsicMethod],
+	["entries", Set.prototype.entries as unknown as ReadonlyIntrinsicMethod],
+	["keys", Set.prototype.keys as unknown as ReadonlyIntrinsicMethod],
+	["values", Set.prototype.values as unknown as ReadonlyIntrinsicMethod],
+	[
+		Symbol.iterator,
+		Set.prototype[Symbol.iterator] as unknown as ReadonlyIntrinsicMethod,
+	],
+]);
+const SET_SIZE_GETTER = Object.getOwnPropertyDescriptor(Set.prototype, "size")
+	?.get as ReadonlyIntrinsicMethod | undefined;
+const DATE_READ_METHODS = new Map<PropertyKey, ReadonlyIntrinsicMethod>();
+for (const property of Reflect.ownKeys(Date.prototype)) {
+	if (
+		property === "constructor" ||
+		(typeof property === "string" && property.startsWith("set"))
+	) {
+		continue;
+	}
+	const descriptor = Object.getOwnPropertyDescriptor(Date.prototype, property);
+	if (typeof descriptor?.value === "function") {
+		DATE_READ_METHODS.set(
+			property,
+			descriptor.value as ReadonlyIntrinsicMethod,
+		);
+	}
+}
+
 function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 	const views = new WeakMap<object, unknown>();
-	const parseResultMethods = new Set<PropertyKey>([
+	const dataFirstValidationMethods = new Set<PropertyKey>([
 		"parse",
 		"safeParse",
 		"parseAsync",
@@ -371,8 +416,186 @@ function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 		"safeDecode",
 		"safeEncodeAsync",
 		"safeDecodeAsync",
+	]);
+	const parseResultMethods = new Set<PropertyKey>([
+		...dataFirstValidationMethods,
 		"toJSONSchema",
 	]);
+	const unsafeCallbackMessage =
+		"callback-bearing schema arguments are not supported";
+
+	function rejectUnsafeCallback(): never {
+		throw new TypeError(unsafeCallbackMessage);
+	}
+
+	function inspectCallbackValues(
+		source: object,
+		seen: WeakSet<object>,
+		skipConstructor: boolean,
+	): void {
+		let keys: readonly PropertyKey[];
+		try {
+			keys = Reflect.ownKeys(source);
+		} catch {
+			rejectUnsafeCallback();
+		}
+		for (const key of keys) {
+			if (skipConstructor && key === "constructor") continue;
+			let descriptor: PropertyDescriptor | undefined;
+			try {
+				descriptor = Object.getOwnPropertyDescriptor(source, key);
+			} catch {
+				rejectUnsafeCallback();
+			}
+			if (!descriptor) continue;
+			if (!("value" in descriptor)) rejectUnsafeCallback();
+			assertCallbackFreeValue(descriptor.value, seen);
+		}
+	}
+
+	function isOpaqueValidationArgument(value: object): boolean {
+		try {
+			if (value instanceof z.ZodType) return true;
+			const internalDescriptor = Object.getOwnPropertyDescriptor(value, "_zod");
+			if (!internalDescriptor || !("value" in internalDescriptor)) {
+				return false;
+			}
+			const internal = internalDescriptor.value;
+			return (
+				typeof internal === "object" &&
+				internal !== null &&
+				typeof (internal as { constr?: unknown }).constr === "function" &&
+				"def" in internal
+			);
+		} catch {
+			rejectUnsafeCallback();
+		}
+	}
+
+	function assertCallbackFreeValue(
+		value: unknown,
+		seen: WeakSet<object>,
+	): void {
+		if (typeof value === "function") rejectUnsafeCallback();
+		if (typeof value !== "object" || value === null || seen.has(value)) {
+			return;
+		}
+		seen.add(value);
+		if (isOpaqueValidationArgument(value)) return;
+
+		inspectCallbackValues(value, seen, false);
+		if (
+			Array.isArray(value) ||
+			value instanceof Map ||
+			value instanceof Set ||
+			value instanceof WeakMap ||
+			value instanceof WeakSet ||
+			value instanceof Date ||
+			value instanceof RegExp ||
+			value instanceof Promise ||
+			ArrayBuffer.isView(value)
+		) {
+			return;
+		}
+
+		let prototype: object | null;
+		try {
+			prototype = Object.getPrototypeOf(value);
+		} catch {
+			rejectUnsafeCallback();
+		}
+		while (prototype && prototype !== Object.prototype) {
+			inspectCallbackValues(prototype, seen, true);
+			try {
+				prototype = Object.getPrototypeOf(prototype);
+			} catch {
+				rejectUnsafeCallback();
+			}
+		}
+	}
+
+	function assertCallbackFreeArguments(args: readonly unknown[]): void {
+		const seen = new WeakSet<object>();
+		for (const argument of args) assertCallbackFreeValue(argument, seen);
+	}
+
+	function readOption(options: object, property: PropertyKey): unknown {
+		try {
+			return Reflect.get(options, property, options);
+		} catch {
+			rejectUnsafeCallback();
+		}
+	}
+
+	function optionRecord(value: unknown): object {
+		if (typeof value !== "object" || value === null || Array.isArray(value)) {
+			rejectUnsafeCallback();
+		}
+		return value;
+	}
+
+	function sanitizeParseOptions(value: unknown): object | undefined {
+		if (value === undefined) return undefined;
+		const options = optionRecord(value);
+		if (readOption(options, "error") !== undefined) rejectUnsafeCallback();
+
+		const safe = Object.create(null) as Record<string, unknown>;
+		for (const property of ["reportInput", "jitless"] as const) {
+			const option = readOption(options, property);
+			if (option === undefined) continue;
+			if (typeof option !== "boolean") rejectUnsafeCallback();
+			safe[property] = option;
+		}
+		return Object.freeze(safe);
+	}
+
+	function sanitizeJsonSchemaOptions(value: unknown): object | undefined {
+		if (value === undefined) return undefined;
+		const options = optionRecord(value);
+		for (const property of [
+			"override",
+			"processors",
+			"metadata",
+			"external",
+		] as const) {
+			if (readOption(options, property) !== undefined) {
+				rejectUnsafeCallback();
+			}
+		}
+
+		const safe = Object.create(null) as Record<string, unknown>;
+		for (const property of [
+			"target",
+			"unrepresentable",
+			"io",
+			"cycles",
+			"reused",
+		] as const) {
+			const option = readOption(options, property);
+			if (option === undefined) continue;
+			if (typeof option !== "string") rejectUnsafeCallback();
+			safe[property] = option;
+		}
+		return Object.freeze(safe);
+	}
+
+	function prepareSafeSchemaMethodArguments(
+		property: PropertyKey,
+		args: readonly unknown[],
+	): readonly unknown[] {
+		assertCallbackFreeArguments(
+			dataFirstValidationMethods.has(property) ? args.slice(1) : args,
+		);
+		if (dataFirstValidationMethods.has(property)) {
+			const options = sanitizeParseOptions(args[1]);
+			return options === undefined ? [args[0]] : [args[0], options];
+		}
+		if (property === "toJSONSchema") {
+			const options = sanitizeJsonSchemaOptions(args[0]);
+			return options === undefined ? [] : [options];
+		}
+		return args;
+	}
 
 	function readonlyView(value: unknown): unknown {
 		if (
@@ -395,16 +618,13 @@ function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 			views.set(value, detached);
 			return Object.freeze(detached);
 		}
-		if (value instanceof Date) {
-			const detached = new Date(value.getTime());
-			views.set(value, detached);
-			return Object.freeze(detached);
-		}
+		if (value instanceof Date) return dateFacade(value);
 		return objectFacade(value);
 	}
 
 	function functionFacade(value: (...args: never[]) => unknown): unknown {
 		const wrapped = function (this: unknown, ...args: unknown[]) {
+			assertCallbackFreeArguments(args);
 			const result = new.target
 				? Reflect.construct(value, args)
 				: Reflect.apply(value, this, args);
@@ -421,22 +641,128 @@ function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 		return Object.freeze(detached);
 	}
 
+	const rejectedMutation = Object.freeze((): never => {
+		throw new TypeError("readonly detached view");
+	});
+
 	function mapFacade(
 		value: ReadonlyMap<unknown, unknown>,
 	): ReadonlyMap<unknown, unknown> {
 		const detached = new Map<unknown, unknown>();
-		views.set(value, detached);
+		let facade: ReadonlyMap<unknown, unknown>;
+		facade = new Proxy(detached, {
+			defineProperty: () => false,
+			deleteProperty: () => false,
+			get: (target, property) => {
+				if (
+					property === "set" ||
+					property === "delete" ||
+					property === "clear"
+				) {
+					return rejectedMutation;
+				}
+				if (property === "forEach") {
+					return Object.freeze((callback: unknown, thisArg?: unknown): void => {
+						if (typeof callback !== "function") {
+							throw new TypeError("Map forEach callback missing");
+						}
+						for (const [key, item] of target) {
+							Reflect.apply(callback, thisArg, [item, key, facade]);
+						}
+					});
+				}
+				if (property === "size" && MAP_SIZE_GETTER) {
+					return Reflect.apply(MAP_SIZE_GETTER, target, []);
+				}
+				const intrinsic = MAP_READ_METHODS.get(property);
+				if (intrinsic) {
+					return Object.freeze((...args: unknown[]) =>
+						Reflect.apply(intrinsic, target, args),
+					);
+				}
+				return readonlyView(Reflect.get(target, property, facade));
+			},
+			set: () => false,
+			setPrototypeOf: () => false,
+		});
+		views.set(value, facade);
+		views.set(facade, facade);
 		for (const [key, item] of value) {
 			detached.set(readonlyView(key), readonlyView(item));
 		}
-		return Object.freeze(detached);
+		Object.freeze(detached);
+		return facade;
 	}
 
 	function setFacade(value: ReadonlySet<unknown>): ReadonlySet<unknown> {
 		const detached = new Set<unknown>();
-		views.set(value, detached);
+		let facade: ReadonlySet<unknown>;
+		facade = new Proxy(detached, {
+			defineProperty: () => false,
+			deleteProperty: () => false,
+			get: (target, property) => {
+				if (
+					property === "add" ||
+					property === "delete" ||
+					property === "clear"
+				) {
+					return rejectedMutation;
+				}
+				if (property === "forEach") {
+					return Object.freeze((callback: unknown, thisArg?: unknown): void => {
+						if (typeof callback !== "function") {
+							throw new TypeError("Set forEach callback missing");
+						}
+						for (const item of target) {
+							Reflect.apply(callback, thisArg, [item, item, facade]);
+						}
+					});
+				}
+				if (property === "size" && SET_SIZE_GETTER) {
+					return Reflect.apply(SET_SIZE_GETTER, target, []);
+				}
+				const intrinsic = SET_READ_METHODS.get(property);
+				if (intrinsic) {
+					return Object.freeze((...args: unknown[]) =>
+						Reflect.apply(intrinsic, target, args),
+					);
+				}
+				return readonlyView(Reflect.get(target, property, facade));
+			},
+			set: () => false,
+			setPrototypeOf: () => false,
+		});
+		views.set(value, facade);
+		views.set(facade, facade);
 		for (const item of value) detached.add(readonlyView(item));
-		return Object.freeze(detached);
+		Object.freeze(detached);
+		return facade;
+	}
+
+	function dateFacade(value: Date): Date {
+		const detached = new Date(value.getTime());
+		const facade = new Proxy(detached, {
+			defineProperty: () => false,
+			deleteProperty: () => false,
+			get: (target, property) => {
+				if (typeof property === "string" && property.startsWith("set")) {
+					return rejectedMutation;
+				}
+				const intrinsic = DATE_READ_METHODS.get(property);
+				if (intrinsic) {
+					return Object.freeze((...args: unknown[]) =>
+						Reflect.apply(intrinsic, target, args),
+					);
+				}
+				return readonlyView(Reflect.get(target, property, facade));
+			},
+			set: () => false,
+			setPrototypeOf: () => false,
+		});
+		views.set(value, facade);
+		views.set(facade, facade);
+		Object.freeze(detached);
+		return facade;
 	}
 
 	function objectFacade(value: object): object {
@@ -455,9 +781,10 @@ function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 		method: (...args: never[]) => unknown,
 		receiver: object,
 	): (...args: unknown[]) => unknown {
-		return Object.freeze((...args: unknown[]) =>
-			readonlyView(Reflect.apply(method, receiver, args)),
-		);
+		return Object.freeze((...args: unknown[]) => {
+			assertCallbackFreeArguments(args);
+			return readonlyView(Reflect.apply(method, receiver, args));
+		});
 	}
 
 	function copyReadonlyProperties(
@@ -581,7 +908,8 @@ function createReadonlyValidationFacade<T extends z.ZodType>(schema: T): T {
 		}
 
 		return Object.freeze((...args: unknown[]) => {
-			const result = Reflect.apply(method, target, args);
+			const safeArgs = prepareSafeSchemaMethodArguments(property, args);
+			const result = Reflect.apply(method, target, safeArgs);
 			if (result instanceof z.ZodType) {
 				return isolateValidationGraph(result, "derived-schema");
 			}