test(api): verify refresh-policy empty inputs and boundaries

Author: Mohammedsami001

services/github/refresh-policy.empty-fallback.test.ts

@@ -0,0 +1,87 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { RefreshPolicy } from './refresh-policy';
+
+// Mock the quota monitor to avoid interference
+vi.mock('./quota-monitor', () => ({
+  quotaMonitor: {
+    isQuotaLow: vi.fn(() => false),
+    incrementRefreshCount: vi.fn(),
+  },
+}));
+
+describe('RefreshPolicy - Edge Cases & Empty/Missing Inputs', () => {
+  let policy: RefreshPolicy;
+
+  beforeEach(() => {
+    policy = RefreshPolicy.getInstance();
+    policy.reset();
+    vi.clearAllMocks();
+  });
+
+  it('Empty/Whitespace Usernames: handles empty and whitespace strings gracefully', () => {
+    const emptyUser = '';
+    const spaceUser = '   ';
+
+    // Should be allowed initially
+    expect(policy.isRefreshAllowed(emptyUser)).toBe(true);
+    expect(policy.isRefreshAllowed(spaceUser)).toBe(true);
+
+    // Record refresh
+    policy.recordRefresh(emptyUser);
+
+    // Both should now be restricted because '   '.trim() === ''.trim()
+    expect(policy.isRefreshAllowed(emptyUser)).toBe(false);
+    expect(policy.isRefreshAllowed(spaceUser)).toBe(false);
+  });
+
+  it('Negative Cooldown Boundaries: clamps negative cooldown durations to 0', () => {
+    policy.setCooldown(-5000); // Should be clamped to 0
+    policy.recordRefresh('testuser');
+
+    // Since cooldown is clamped to 0, refresh is immediately allowed again
+    expect(policy.isRefreshAllowed('testuser')).toBe(true);
+    expect(policy.getRemainingCooldown('testuser')).toBe(0);
+  });
+
+  it('Unrecorded Users Fallback: returns safe fallback value (0) for unrecorded users', () => {
+    const remaining = policy.getRemainingCooldown('never-seen-before');
+    expect(remaining).toBe(0); // Should be exactly 0, not undefined/NaN
+
+    // Ensure we aren't getting false negatives
+    expect(policy.isRefreshAllowed('never-seen-before')).toBe(true);
+  });
+
+  it('Missing/Undefined Parameters: throws TypeError predictably when passed undefined/null', () => {
+    // Bypassing TS to simulate runtime missing parameters in JS environments
+    const undefinedUser = undefined as unknown as string;
+    const nullUser = null as unknown as string;
+
+    // We expect it to throw because .trim() is called on undefined/null
+    expect(() => policy.isRefreshAllowed(undefinedUser)).toThrowError(TypeError);
+    expect(() => policy.isRefreshAllowed(nullUser)).toThrowError(TypeError);
+
+    expect(() => policy.recordRefresh(undefinedUser)).toThrowError(TypeError);
+    expect(() => policy.getRemainingCooldown(nullUser)).toThrowError(TypeError);
+  });
+
+  it('Singleton Reset Stability: clears all state and restores defaults on reset', () => {
+    // Change state
+    policy.setCooldown(10000);
+    policy.recordRefresh('user-a');
+
+    // Verify state was changed
+    expect(policy.isRefreshAllowed('user-a')).toBe(false);
+
+    // Reset
+    policy.reset();
+
+    // Verify map is completely cleared
+    expect(policy.isRefreshAllowed('user-a')).toBe(true);
+    expect(policy.getRemainingCooldown('user-a')).toBe(0);
+
+    // Verify cooldown is restored to default (5 * 60 * 1000 = 300000ms)
+    policy.recordRefresh('user-a');
+    // It should be 300000 right after recording (elapsed ~ 0)
+    expect(policy.getRemainingCooldown('user-a')).toBe(300000);
+  });
+});