feat: 新增 DB checker — 支持 PostgreSQL/MySQL/SQLite 连接测试与 SQL 查询断言

- 实现 db 类型 checker，使用 Bun 内置 SQL 类
- 支持 db.url 连接字符串和可选 db.query 查询语句
- expect 支持 maxDurationMs、rowCount、rows 逐列校验
- 凭据屏蔽序列化输出
- SQLite 内存数据库测试覆盖

tests/server/checker/runner/db/expect.test.ts

@@ -0,0 +1,134 @@
+import { describe, expect, test } from "bun:test";
+
+import { checkRowCount, checkRows } from "../../../../../src/server/checker/runner/db/expect";
+
+describe("checkRowCount", () => {
+  test("空数组通过 rowCount gte 0", () => {
+    const result = checkRowCount([], { gte: 0 });
+    expect(result.matched).toBe(true);
+    expect(result.failure).toBeNull();
+  });
+
+  test("非数组视为 0 行", () => {
+    const result = checkRowCount(null, { gte: 0 });
+    expect(result.matched).toBe(true);
+  });
+
+  test("rowCount gte 通过", () => {
+    const result = checkRowCount([1, 2, 3], { gte: 3 });
+    expect(result.matched).toBe(true);
+  });
+
+  test("rowCount gte 失败", () => {
+    const result = checkRowCount([1, 2], { gte: 3 });
+    expect(result.matched).toBe(false);
+    expect(result.failure!.phase).toBe("rowCount");
+    expect(result.failure!.path).toBe("rowCount");
+  });
+
+  test("rowCount equals 通过", () => {
+    const result = checkRowCount([1, 2, 3], { equals: 3 });
+    expect(result.matched).toBe(true);
+  });
+
+  test("rowCount equals 失败", () => {
+    const result = checkRowCount([1, 2, 3], { equals: 5 });
+    expect(result.matched).toBe(false);
+  });
+});
+
+describe("checkRows", () => {
+  test("非数组返回失败", () => {
+    const result = checkRows(null, [{ col: 1 }]);
+    expect(result.matched).toBe(false);
+    expect(result.failure!.phase).toBe("row");
+    expect(result.failure!.path).toBe("rows");
+  });
+
+  test("空规则通过", () => {
+    const result = checkRows([], []);
+    expect(result.matched).toBe(true);
+  });
+
+  test("单行单列匹配（字面量）", () => {
+    const result = checkRows([{ col: "value" }], [{ col: "value" }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("单行单列匹配（operator）", () => {
+    const result = checkRows([{ col: 100 }], [{ col: { gte: 50 } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("单行单列不匹配", () => {
+    const result = checkRows([{ col: 10 }], [{ col: { gte: 50 } }]);
+    expect(result.matched).toBe(false);
+    expect(result.failure!.phase).toBe("row");
+    expect(result.failure!.path).toBe("rows[0].col");
+  });
+
+  test("多行多列全部匹配", () => {
+    const result = checkRows(
+      [
+        { id: 1, name: "Alice" },
+        { id: 2, name: "Bob" },
+      ],
+      [{ id: { gte: 1 } }, { name: "Bob" }],
+    );
+    expect(result.matched).toBe(true);
+  });
+
+  test("多行中有一行不匹配", () => {
+    const result = checkRows([{ col: 1 }, { col: 2 }], [{ col: { gte: 2 } }, { col: { gte: 3 } }]);
+    expect(result.matched).toBe(false);
+    // 第一行 { col: 1 } 不满足 { gte: 2 }，所以失败在第一行
+    expect(result.failure!.path).toBe("rows[0].col");
+  });
+
+  test("结果行数不足", () => {
+    const result = checkRows([{ col: 1 }], [{ col: 1 }, { col: 2 }]);
+    expect(result.matched).toBe(false);
+    expect(result.failure!.message).toContain("行数不足");
+  });
+
+  test("只检查声明的列", () => {
+    const result = checkRows([{ col: 1, other: "ignored" }], [{ col: { gte: 0 } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("行不是对象返回失败", () => {
+    const result = checkRows(["not-an-object"] as unknown[], [{ col: 1 }]);
+    expect(result.matched).toBe(false);
+    expect(result.failure!.path).toBe("rows[0]");
+  });
+
+  test("列不存在视为 undefined", () => {
+    const result = checkRows([{}], [{ col: { exists: false } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("列存在且值为 null", () => {
+    const result = checkRows([{ col: null }], [{ col: { empty: true } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("contains 匹配字符串", () => {
+    const result = checkRows([{ text: "hello world" }], [{ text: { contains: "hello" } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("match 正则匹配", () => {
+    const result = checkRows([{ code: "ABC-123" }], [{ code: { match: "^ABC-" } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("多个断言同时满足", () => {
+    const result = checkRows([{ val: 50 }], [{ val: { gte: 10, lte: 100 } }]);
+    expect(result.matched).toBe(true);
+  });
+
+  test("多个断言中有一个不满足", () => {
+    const result = checkRows([{ val: 50 }], [{ val: { gte: 10, lte: 30 } }]);
+    expect(result.matched).toBe(false);
+  });
+});