fix: improve auth profile failover

src/agents/auth-profiles.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 
 import {
   type AuthProfileStore,
+  calculateAuthProfileCooldownMs,
   resolveAuthProfileOrder,
 } from "./auth-profiles.js";
 
@@ -105,4 +106,87 @@ describe("resolveAuthProfileOrder", () => {
     });
     expect(order).toEqual(["anthropic:oauth", "anthropic:default"]);
   });
+
+  it("orders by lastUsed when no explicit order exists", () => {
+    const order = resolveAuthProfileOrder({
+      store: {
+        version: 1,
+        profiles: {
+          "anthropic:a": {
+            type: "oauth",
+            provider: "anthropic",
+            access: "access-token",
+            refresh: "refresh-token",
+            expires: Date.now() + 60_000,
+          },
+          "anthropic:b": {
+            type: "api_key",
+            provider: "anthropic",
+            key: "sk-b",
+          },
+          "anthropic:c": {
+            type: "api_key",
+            provider: "anthropic",
+            key: "sk-c",
+          },
+        },
+        usageStats: {
+          "anthropic:a": { lastUsed: 200 },
+          "anthropic:b": { lastUsed: 100 },
+          "anthropic:c": { lastUsed: 300 },
+        },
+      },
+      provider: "anthropic",
+    });
+    expect(order).toEqual(["anthropic:b", "anthropic:a", "anthropic:c"]);
+  });
+
+  it("pushes cooldown profiles to the end, ordered by cooldown expiry", () => {
+    const now = Date.now();
+    const order = resolveAuthProfileOrder({
+      store: {
+        version: 1,
+        profiles: {
+          "anthropic:ready": {
+            type: "api_key",
+            provider: "anthropic",
+            key: "sk-ready",
+          },
+          "anthropic:cool1": {
+            type: "oauth",
+            provider: "anthropic",
+            access: "access-token",
+            refresh: "refresh-token",
+            expires: now + 60_000,
+          },
+          "anthropic:cool2": {
+            type: "api_key",
+            provider: "anthropic",
+            key: "sk-cool",
+          },
+        },
+        usageStats: {
+          "anthropic:ready": { lastUsed: 50 },
+          "anthropic:cool1": { cooldownUntil: now + 5_000 },
+          "anthropic:cool2": { cooldownUntil: now + 1_000 },
+        },
+      },
+      provider: "anthropic",
+    });
+    expect(order).toEqual([
+      "anthropic:ready",
+      "anthropic:cool2",
+      "anthropic:cool1",
+    ]);
+  });
+});
+
+describe("auth profile cooldowns", () => {
+  it("applies exponential backoff with a 1h cap", () => {
+    expect(calculateAuthProfileCooldownMs(1)).toBe(60_000);
+    expect(calculateAuthProfileCooldownMs(2)).toBe(5 * 60_000);
+    expect(calculateAuthProfileCooldownMs(3)).toBe(25 * 60_000);
+    expect(calculateAuthProfileCooldownMs(4)).toBe(60 * 60_000);
+    expect(calculateAuthProfileCooldownMs(5)).toBe(60 * 60_000);
+  });
 });