feat: 增强 expect 规则系统，支持多种 body 校验方法和操作符

- 新增 body 分组校验：contains、regex、json（JSONPath）、css（CSS选择器）、xpath
- 新增操作符系统：equals、contains、match、empty、exists、gte、lte、gt、lt
- 新增 headers 响应头校验
- 引入 cheerio、xpath、@xmldom/xmldom 依赖
- BREAKING: expect.bodyContains 迁移至 expect.body.contains

src/server/checker/fetcher.ts

@@ -1,4 +1,5 @@
 import type { CheckResult, ExpectConfig, ResolvedTarget } from "./types";
+import { checkBodyExpect } from "./body-expect";
 
 export async function fetchTarget(target: ResolvedTarget): Promise<CheckResult> {
   const timestamp = new Date().toISOString();
@@ -17,8 +18,9 @@ export async function fetchTarget(target: ResolvedTarget): Promise<CheckResult>
 
     const latencyMs = Math.round(performance.now() - start);
     const body = await response.text();
+    const responseHeaders = headersToRecord(response.headers);
 
-    const matched = checkExpect(response.status, body, latencyMs, target.expect);
+    const matched = checkExpect(response.status, body, latencyMs, responseHeaders, target.expect);
 
     return {
       targetName: target.name,
@@ -38,7 +40,7 @@ export async function fetchTarget(target: ResolvedTarget): Promise<CheckResult>
       success: false,
       statusCode: null,
       latencyMs: null,
-      error: isTimeout ? `请求超时 (${target.timeoutMs}ms)` : (error instanceof Error ? error.message : String(error)),
+      error: isTimeout ? `请求超时 (${target.timeoutMs}ms)` : error instanceof Error ? error.message : String(error),
       matched: false,
     };
   } finally {
@@ -46,14 +48,37 @@ export async function fetchTarget(target: ResolvedTarget): Promise<CheckResult>
   }
 }
 
-export function checkExpect(statusCode: number, body: string, latencyMs: number, expect?: ExpectConfig): boolean {
+function headersToRecord(headers: Headers): Record<string, string> {
+  const result: Record<string, string> = {};
+  headers.forEach((value, key) => {
+    result[key] = value;
+  });
+  return result;
+}
+
+export function checkExpect(
+  statusCode: number,
+  body: string,
+  latencyMs: number,
+  responseHeaders: Record<string, string>,
+  expect?: ExpectConfig,
+): boolean {
   if (!expect) return true;
 
   if (expect.status && !expect.status.includes(statusCode)) {
     return false;
   }
 
-  if (expect.bodyContains && !body.includes(expect.bodyContains)) {
+  if (expect.headers) {
+    for (const [key, expectedValue] of Object.entries(expect.headers)) {
+      const actualValue = responseHeaders[key.toLowerCase()];
+      if (!actualValue || actualValue !== expectedValue) {
+        return false;
+      }
+    }
+  }
+
+  if (!checkBodyExpect(body, expect.body)) {
     return false;
   }