refactor: dedupe provider usage fetch logic and tests

src/infra/provider-usage.fetch.zai.test.ts

@@ -0,0 +1,86 @@
+import { describe, expect, it } from "vitest";
+import { createProviderUsageFetch, makeResponse } from "../test-utils/provider-usage-fetch.js";
+import { fetchZaiUsage } from "./provider-usage.fetch.zai.js";
+
+describe("fetchZaiUsage", () => {
+  it("returns HTTP errors for failed requests", async () => {
+    const mockFetch = createProviderUsageFetch(async () => makeResponse(503, "unavailable"));
+    const result = await fetchZaiUsage("key", 5000, mockFetch);
+
+    expect(result.error).toBe("HTTP 503");
+    expect(result.windows).toHaveLength(0);
+  });
+
+  it("returns API message errors for unsuccessful payloads", async () => {
+    const mockFetch = createProviderUsageFetch(async () =>
+      makeResponse(200, {
+        success: false,
+        code: 500,
+        msg: "quota endpoint disabled",
+      }),
+    );
+
+    const result = await fetchZaiUsage("key", 5000, mockFetch);
+    expect(result.error).toBe("quota endpoint disabled");
+    expect(result.windows).toHaveLength(0);
+  });
+
+  it("parses token and monthly windows with reset times", async () => {
+    const tokenReset = "2026-01-08T00:00:00Z";
+    const minuteReset = "2026-01-08T00:30:00Z";
+    const monthlyReset = "2026-01-31T12:00:00Z";
+    const mockFetch = createProviderUsageFetch(async () =>
+      makeResponse(200, {
+        success: true,
+        code: 200,
+        data: {
+          planName: "Team",
+          limits: [
+            {
+              type: "TOKENS_LIMIT",
+              percentage: 32,
+              unit: 3,
+              number: 6,
+              nextResetTime: tokenReset,
+            },
+            {
+              type: "TOKENS_LIMIT",
+              percentage: 8,
+              unit: 5,
+              number: 15,
+              nextResetTime: minuteReset,
+            },
+            {
+              type: "TIME_LIMIT",
+              percentage: 12.5,
+              unit: 1,
+              number: 30,
+              nextResetTime: monthlyReset,
+            },
+          ],
+        },
+      }),
+    );
+
+    const result = await fetchZaiUsage("key", 5000, mockFetch);
+
+    expect(result.plan).toBe("Team");
+    expect(result.windows).toEqual([
+      {
+        label: "Tokens (6h)",
+        usedPercent: 32,
+        resetAt: new Date(tokenReset).getTime(),
+      },
+      {
+        label: "Tokens (15m)",
+        usedPercent: 8,
+        resetAt: new Date(minuteReset).getTime(),
+      },
+      {
+        label: "Monthly",
+        usedPercent: 12.5,
+        resetAt: new Date(monthlyReset).getTime(),
+      },
+    ]);
+  });
+});