refactor: dedupe provider usage fetch logic and tests

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

@@ -0,0 +1,57 @@
+import { describe, expect, it } from "vitest";
+import { createProviderUsageFetch, makeResponse } from "../test-utils/provider-usage-fetch.js";
+import { fetchCodexUsage } from "./provider-usage.fetch.codex.js";
+
+describe("fetchCodexUsage", () => {
+  it("returns token expired for auth failures", async () => {
+    const mockFetch = createProviderUsageFetch(async () =>
+      makeResponse(401, { error: "unauthorized" }),
+    );
+
+    const result = await fetchCodexUsage("token", undefined, 5000, mockFetch);
+    expect(result.error).toBe("Token expired");
+    expect(result.windows).toHaveLength(0);
+  });
+
+  it("returns HTTP status errors for non-auth failures", async () => {
+    const mockFetch = createProviderUsageFetch(async () =>
+      makeResponse(429, { error: "throttled" }),
+    );
+
+    const result = await fetchCodexUsage("token", undefined, 5000, mockFetch);
+    expect(result.error).toBe("HTTP 429");
+    expect(result.windows).toHaveLength(0);
+  });
+
+  it("parses windows, reset times, and plan balance", async () => {
+    const mockFetch = createProviderUsageFetch(async (_url, init) => {
+      const headers = (init?.headers as Record<string, string> | undefined) ?? {};
+      expect(headers["ChatGPT-Account-Id"]).toBe("acct-1");
+      return makeResponse(200, {
+        rate_limit: {
+          primary_window: {
+            limit_window_seconds: 10_800,
+            used_percent: 35.5,
+            reset_at: 1_700_000_000,
+          },
+          secondary_window: {
+            limit_window_seconds: 86_400,
+            used_percent: 75,
+            reset_at: 1_700_050_000,
+          },
+        },
+        plan_type: "Plus",
+        credits: { balance: "12.5" },
+      });
+    });
+
+    const result = await fetchCodexUsage("token", "acct-1", 5000, mockFetch);
+
+    expect(result.provider).toBe("openai-codex");
+    expect(result.plan).toBe("Plus ($12.50)");
+    expect(result.windows).toEqual([
+      { label: "3h", usedPercent: 35.5, resetAt: 1_700_000_000_000 },
+      { label: "Day", usedPercent: 75, resetAt: 1_700_050_000_000 },
+    ]);
+  });
+});