feat(P17B-1,P17B-2): 补齐采购预算闭环与归档模型接口

server/tests/unit/services/purchaseBudget.test.js

@@ -0,0 +1,41 @@
+const {
+  summarizeBudgetLedgerByPool,
+  buildPurchaseBudgetValidationError,
+} = require("../../../src/services/purchaseBudget");
+
+describe("purchaseBudget service", () => {
+  it("summarizes reserve confirm release by pool", () => {
+    expect(
+      summarizeBudgetLedgerByPool([
+        { budget_pool_id: "pool-1", kind: "reserve", amount: "120.00" },
+        { budget_pool_id: "pool-1", kind: "confirm", amount: "120.00" },
+        { budget_pool_id: "pool-1", kind: "release", amount: "20.00" },
+        { budget_pool_id: "pool-2", kind: "reserve", amount: "80.00" },
+      ]),
+    ).toEqual([
+      {
+        budgetPoolId: "pool-1",
+        reserve: 120,
+        confirm: 120,
+        release: 20,
+        outstanding: 100,
+        confirmPending: 0,
+      },
+      {
+        budgetPoolId: "pool-2",
+        reserve: 80,
+        confirm: 0,
+        release: 0,
+        outstanding: 80,
+        confirmPending: 80,
+      },
+    ]);
+  });
+
+  it("builds VALID_001 validation error", () => {
+    const error = buildPurchaseBudgetValidationError({ budget: "reserve_already_exists" });
+    expect(error.code).toBe("VALID_001");
+    expect(error.statusCode).toBe(409);
+    expect(error.details).toEqual({ budget: "reserve_already_exists" });
+  });
+});