chore: custom expect messages follow-up (#1780)

Author: mxschmitt

playwright/_impl/_assertions.py

@@ -55,9 +55,9 @@ async def _expect_impl(
             if log:
                 log = "\nCall log:\n" + log
             if self._custom_message:
-                out_message = (
-                    f"{self._custom_message}\nExpected value: {expected or '<None>'}"
-                )
+                out_message = self._custom_message
+                if expected is not None:
+                    out_message += f"\nExpected value: '{expected or '<None>'}'"
             else:
                 out_message = (
                     f"{message} '{expected}'" if expected is not None else f"{message}"

tests/async/test_assertions.py

@@ -671,3 +671,20 @@ async def test_should_print_users_message_for_page_based_assertion(
     with pytest.raises(AssertionError) as excinfo:
         await expect(page).to_have_title("old title", timeout=100)
     assert "Page title expected to be" in str(excinfo.value)
+
+
+async def test_should_print_expected_value_with_custom_message(
+    page: Page, server: Server
+) -> None:
+    await page.goto(server.EMPTY_PAGE)
+    await page.set_content("<title>new title</title>")
+    with pytest.raises(AssertionError) as excinfo:
+        await expect(page, "custom-message").to_have_title("old title", timeout=100)
+    assert "custom-message" in str(excinfo.value)
+    assert "Expected value: 'old title'" in str(excinfo.value)
+    with pytest.raises(AssertionError) as excinfo:
+        await expect(page.get_by_text("hello"), "custom-message").to_be_visible(
+            timeout=100
+        )
+    assert "custom-message" in str(excinfo.value)
+    assert "Expected value" not in str(excinfo.value)

tests/sync/test_assertions.py

@@ -759,3 +759,18 @@ def test_should_print_users_message_for_page_based_assertion(
     with pytest.raises(AssertionError) as excinfo:
         expect(page).to_have_title("old title", timeout=100)
     assert "Page title expected to be" in str(excinfo.value)
+
+
+def test_should_print_expected_value_with_custom_message(
+    page: Page, server: Server
+) -> None:
+    page.goto(server.EMPTY_PAGE)
+    page.set_content("<title>new title</title>")
+    with pytest.raises(AssertionError) as excinfo:
+        expect(page, "custom-message").to_have_title("old title", timeout=100)
+    assert "custom-message" in str(excinfo.value)
+    assert "Expected value: 'old title'" in str(excinfo.value)
+    with pytest.raises(AssertionError) as excinfo:
+        expect(page.get_by_text("hello"), "custom-message").to_be_visible(timeout=100)
+    assert "custom-message" in str(excinfo.value)
+    assert "Expected value" not in str(excinfo.value)