test: verify recipient check debounce and abort behavior

app/create/__tests__/page.test.tsx

@@ -405,3 +405,81 @@ describe('CreatePage — contract recipient warning (issue #392)', () => {
     cleanup(root, container);
   });
 });
+
+describe('CreatePage — recipient check debounce (#466)', () => {
+  beforeEach(() => {
+    mockCheckRecipientExists.mockReset().mockResolvedValue(true);
+  });
+
+  it('does not call checkRecipientExists immediately on keystroke', async () => {
+    const { container, root } = renderCreatePage();
+    const recipientInput = container.querySelector('input[placeholder="G…"]') as HTMLInputElement;
+
+    await act(async () => {
+      setFieldValue(recipientInput, TEST_RECIPIENT);
+      // Do NOT wait for the debounce — check immediately
+    });
+
+    expect(mockCheckRecipientExists).not.toHaveBeenCalled();
+
+    // Now wait for the debounce
+    await act(async () => {
+      await new Promise(resolve => setTimeout(resolve, 650));
+    });
+
+    expect(mockCheckRecipientExists).toHaveBeenCalledTimes(1);
+    cleanup(root, container);
+  });
+
+  it('fires only one check after rapid keystrokes within the debounce window', async () => {
+    const { container, root } = renderCreatePage();
+    const recipientInput = container.querySelector('input[placeholder="G…"]') as HTMLInputElement;
+
+    // Type rapidly — each keystroke within the 600ms debounce window
+    await act(async () => {
+      for (let i = 0; i < 5; i++) {
+        setFieldValue(recipientInput, TEST_RECIPIENT.slice(0, 50 + i));
+        await new Promise(resolve => setTimeout(resolve, 100));
+      }
+      setFieldValue(recipientInput, TEST_RECIPIENT);
+      await new Promise(resolve => setTimeout(resolve, 50));
+    });
+
+    // Should not have fired yet (last keystroke was only 50ms ago)
+    expect(mockCheckRecipientExists).not.toHaveBeenCalled();
+
+    await act(async () => {
+      await new Promise(resolve => setTimeout(resolve, 650));
+    });
+
+    expect(mockCheckRecipientExists).toHaveBeenCalledTimes(1);
+    cleanup(root, container);
+  });
+
+  it('aborts the in-flight check when the address changes mid-debounce', async () => {
+    const { container, root } = renderCreatePage();
+    const recipientInput = container.querySelector('input[placeholder="G…"]') as HTMLInputElement;
+
+    // Type first address and wait for debounce to fire
+    await act(async () => {
+      setFieldValue(recipientInput, TEST_RECIPIENT);
+      await new Promise(resolve => setTimeout(resolve, 650));
+    });
+
+    expect(mockCheckRecipientExists).toHaveBeenCalledTimes(1);
+
+    // Change address before the check completes
+    const SECOND_RECIPIENT = 'GCBBG5LDGECWWCJN7NGP6JIVY6M2PDMZXHFIWDBMR5WKZFGF5NPOILFH';
+    mockCheckRecipientExists.mockClear();
+
+    await act(async () => {
+      setFieldValue(recipientInput, SECOND_RECIPIENT);
+      // The old check should be aborted — only the new one should fire
+      await new Promise(resolve => setTimeout(resolve, 650));
+    });
+
+    expect(mockCheckRecipientExists).toHaveBeenCalledTimes(1);
+    expect(mockCheckRecipientExists).toHaveBeenCalledWith(SECOND_RECIPIENT, expect.any(Object));
+    cleanup(root, container);
+  });
+});