API Mock Server

import {  ALLOWED_METHODS,  MAX_DELAY_MS,  MAX_PATH_LENGTH,  MOCK_KEY_PREFIX,  SLUG_LENGTH,} from "../constants/defaults";import type { CreateMockRequest, HttpMethod, MockConfig, MockSummary } from "../types/mock";const SLUG_ALPHABET = "abcdefghijklmnopqrstuvwxyz0123456789";export function mockKey(slug: string): string {  return `${MOCK_KEY_PREFIX}${slug}`;}export function validateSlug(input: string | undefined): string | null {  if (!input || typeof input !== "string") return null;  const trimmed = input.trim();  if (!trimmed || trimmed.length > 64) return null;  if (!/^[a-z0-9-]+$/.test(trimmed)) return null;  return trimmed;}export function validatePath(input: string | undefined): string | null {  if (!input || typeof input !== "string") return null;  const trimmed = input.trim();  if (!trimmed || trimmed.length > MAX_PATH_LENGTH) return null;  if (!trimmed.startsWith("/")) return null;  return trimmed;}export function validateMethod(input: string | undefined): HttpMethod | null {  if (!input || typeof input !== "string") return null;  const normalized = input.trim().toUpperCase();  if (!ALLOWED_METHODS.includes(normalized as HttpMethod)) return null;  return normalized as HttpMethod;}export function validateStatus(input: unknown): number | null {  if (typeof input !== "number" || !Number.isInteger(input)) return null;  if (input < 100 || input > 599) return null;  return input;}export function validateJsonBody(input: unknown): unknown | null {  if (input === undefined) return null;  if (input === null) return null;  if (typeof input === "object") return input;  if (typeof input === "string" || typeof input === "number" || typeof input === "boolean") {    return input;  }  return null;}export function validateDelayMs(input: unknown): number | undefined | null {  if (input === undefined) return undefined;  if (typeof input !== "number" || !Number.isInteger(input)) return null;  if (input < 0 || input > MAX_DELAY_MS) return null;  return input;}export function validateCreateMockRequest(body: CreateMockRequest): {  path: string;  method: HttpMethod;  status: number;  body: unknown;  delayMs?: number;} | null {  const path = validatePath(body.path);  const method = validateMethod(body.method);  const status = validateStatus(body.status);  const responseBody = validateJsonBody(body.body);  const delayMs = validateDelayMs(body.delayMs);  if (!path || !method || status === null || responseBody === null || delayMs === null) {    return null;  }  return { path, method, status, body: responseBody, delayMs };}export function generateSlug(): string {  const bytes = new Uint8Array(SLUG_LENGTH);  crypto.getRandomValues(bytes);  return Array.from(bytes, (byte) => SLUG_ALPHABET[byte % SLUG_ALPHABET.length]).join("");}export async function saveMock(kv: KVNamespace, config: MockConfig): Promise<void> {  await kv.put(mockKey(config.slug), JSON.stringify(config));}export async function getMock(kv: KVNamespace, slug: string): Promise<MockConfig | null> {  const raw = await kv.get(mockKey(slug));  if (!raw) return null;  return parseMockConfig(raw, slug);}export async function deleteMock(kv: KVNamespace, slug: string): Promise<void> {  await kv.delete(mockKey(slug));}export async function listMocks(kv: KVNamespace): Promise<MockSummary[]> {  const listed = await kv.list({ prefix: MOCK_KEY_PREFIX });  const summaries: MockSummary[] = [];  for (const key of listed.keys) {    const slug = key.name.slice(MOCK_KEY_PREFIX.length);    const raw = await kv.get(key.name);    if (!raw) continue;    const config = parseMockConfig(raw, slug);    if (!config) continue;    summaries.push({      slug: config.slug,      path: config.path,      method: config.method,      status: config.status,      delayMs: config.delayMs,      createdAt: config.createdAt,    });  }  return summaries.sort((a, b) => a.slug.localeCompare(b.slug));}export function parseMockConfig(raw: string, slug: string): MockConfig | null {  try {    const parsed = JSON.parse(raw) as Partial<MockConfig>;    const method = validateMethod(parsed.method);    const status = validateStatus(parsed.status);    const path = validatePath(parsed.path);    const body = validateJsonBody(parsed.body);    if (!method || status === null || !path || body === null) return null;    return {      slug: parsed.slug ?? slug,      path,      method,      status,      body,      delayMs: parsed.delayMs,      createdAt: parsed.createdAt ?? new Date(0).toISOString(),    };  } catch {    return null;  }}export function matchesMockRequest(  config: MockConfig,  requestMethod: string,  requestPath: string): boolean {  if (config.method !== requestMethod.toUpperCase()) return false;  const normalizedRequestPath = normalizePath(requestPath);  const normalizedConfigPath = normalizePath(config.path);  if (normalizedRequestPath === normalizedConfigPath) return true;  if (normalizedRequestPath.startsWith(`${normalizedConfigPath}/`)) return true;  return false;}export function normalizePath(path: string): string {  if (path.length > 1 && path.endsWith("/")) {    return path.slice(0, -1);  }  return path;}export async function sleep(ms: number): Promise<void> {  if (ms <= 0) return;  await new Promise((resolve) => setTimeout(resolve, ms));}export function buildMockResponse(config: MockConfig): Response {  return Response.json(config.body, { status: config.status });}