feat: add provider usage tracking

src/infra/provider-usage.test.ts

@@ -0,0 +1,123 @@
+import { describe, expect, it, vi } from "vitest";
+import {
+  formatUsageReportLines,
+  formatUsageSummaryLine,
+  loadProviderUsageSummary,
+  type UsageSummary,
+} from "./provider-usage.js";
+
+describe("provider usage formatting", () => {
+  it("returns null when no usage is available", () => {
+    const summary: UsageSummary = { updatedAt: 0, providers: [] };
+    expect(formatUsageSummaryLine(summary)).toBeNull();
+  });
+
+  it("picks the most-used window for summary line", () => {
+    const summary: UsageSummary = {
+      updatedAt: 0,
+      providers: [
+        {
+          provider: "anthropic",
+          displayName: "Claude",
+          windows: [
+            { label: "5h", usedPercent: 10 },
+            { label: "Week", usedPercent: 60 },
+          ],
+        },
+      ],
+    };
+    const line = formatUsageSummaryLine(summary, { now: 0 });
+    expect(line).toContain("Claude");
+    expect(line).toContain("40% left");
+    expect(line).toContain("(Week");
+  });
+
+  it("prints provider errors in report output", () => {
+    const summary: UsageSummary = {
+      updatedAt: 0,
+      providers: [
+        {
+          provider: "openai-codex",
+          displayName: "Codex",
+          windows: [],
+          error: "Token expired",
+        },
+      ],
+    };
+    const lines = formatUsageReportLines(summary);
+    expect(lines.join("\n")).toContain("Codex: Token expired");
+  });
+
+  it("includes reset countdowns in report lines", () => {
+    const now = Date.UTC(2026, 0, 7, 0, 0, 0);
+    const summary: UsageSummary = {
+      updatedAt: now,
+      providers: [
+        {
+          provider: "anthropic",
+          displayName: "Claude",
+          windows: [
+            { label: "5h", usedPercent: 20, resetAt: now + 60_000 },
+          ],
+        },
+      ],
+    };
+    const lines = formatUsageReportLines(summary, { now });
+    expect(lines.join("\n")).toContain("resets 1m");
+  });
+});
+
+describe("provider usage loading", () => {
+  it("loads usage snapshots with injected auth", async () => {
+    const makeResponse = (status: number, body: unknown) =>
+      ({
+        ok: status >= 200 && status < 300,
+        status,
+        json: async () => body,
+      }) as any;
+
+    const mockFetch = vi.fn(async (input: any) => {
+      const url = String(input);
+      if (url.includes("api.anthropic.com")) {
+        return makeResponse(200, {
+          five_hour: { utilization: 20, resets_at: "2026-01-07T01:00:00Z" },
+        });
+      }
+      if (url.includes("api.z.ai")) {
+        return makeResponse(200, {
+          success: true,
+          code: 200,
+          data: {
+            planName: "Pro",
+            limits: [
+              {
+                type: "TOKENS_LIMIT",
+                percentage: 25,
+                unit: 3,
+                number: 6,
+                nextResetTime: "2026-01-07T06:00:00Z",
+              },
+            ],
+          },
+        });
+      }
+      return makeResponse(404, "not found");
+    });
+
+    const summary = await loadProviderUsageSummary({
+      now: Date.UTC(2026, 0, 7, 0, 0, 0),
+      auth: [
+        { provider: "anthropic", token: "token-1" },
+        { provider: "zai", token: "token-2" },
+      ],
+      fetch: mockFetch,
+    });
+
+    expect(summary.providers).toHaveLength(2);
+    const claude = summary.providers.find((p) => p.provider === "anthropic");
+    const zai = summary.providers.find((p) => p.provider === "zai");
+    expect(claude?.windows[0]?.label).toBe("5h");
+    expect(zai?.plan).toBe("Pro");
+    expect(mockFetch).toHaveBeenCalled();
+  });
+});