LibWeb: Update add_libweb_test.py to support Screenshot, Ref, and Layout

Changed the usage from `add_libweb_test.py test_name.html` to
`add_libweb_test.py test_name.html test_type` with no default,
and supports automatically generating input/output files in the
right directories for test types Screenshot, Text, Ref, and Layout.

Co-authored-by: Sam Atkins <sam@ladybird.org>

Documentation/Testing.md

@@ -123,16 +123,19 @@ That is, you give `./Meta/WPT.sh import` the path part of any `http://wpt.live/`
 
 ## Writing tests
 
-Running `Tests/LibWeb/add_libweb_test.py your-new-test-name` will create a new test HTML file in
-`Tests/LibWeb/Text/input/your-new-test-name.html` with the correct boilerplate code for a Text test — along with
-a corresponding expectations file in `Tests/LibWeb/Text/expected/your-new-test-name.txt`.
+Running `Tests/LibWeb/add_libweb_test.py your-new-test-name test_type` will create a new test HTML file in 
+`Tests/LibWeb/test_type(/input)` (`/input` is appended for Text and Layout tests) with the correct boilerplate
+code for a `test_type` test — along with a corresponding expectations file in the appropriate directory, e.g.,
+`Tests/LibWeb/Text/expected/your-new-test-name.txt`, for a Text test, or
+`Tests/LibWeb/Ref/reference/your-new-test-name.txt` for a Ref test. The accepted `test_types` are "Text",
+"Ref", "Screenshot", and "Layout".
 
-After you update/replace the generated boilerplate in your `your-new-test-name.html` test file with your actual test,
-running `./Meta/ladybird.sh run headless-browser --run-tests "${LADYBIRD_SOURCE_DIR}/Tests/LibWeb" --rebaseline -f Text/input/foobar.html` will
-regenerate the corresponding expectations file — to match the actual output from your updated test (where
-`/opt/ladybird` should be replaced with the absolute path your ladybird clone in your local environment).
+If you make a new Text or Layout test, after you update/replace the generated boilerplate in your 
+`your-new-test-name.html` test file with your actual test, running 
+`./Meta/ladybird.sh run headless-browser --run-tests "./Tests/LibWeb" --rebaseline -f Text/input/foobar.html` 
+will regenerate the corresponding expectations file to match the actual output from your updated test.
 
-Future versions of the `add_libweb_test.py` script will support other test types.
+If you add a new Ref or Screenshot test, you'll need to supply the equivalently rendering HTML manually.
 
 ### Text tests
 

Tests/LibWeb/add_libweb_test.py

@@ -9,31 +9,52 @@ from pathlib import Path
 TEST_DIR = Path(__file__).resolve().parent
 
 
-def create_text_test(test_name: str, is_async: bool = False) -> None:
+def create_test(test_name: str, test_type: str, is_async: bool = False) -> None:
     """
-    Create a new Text type test file with the given test name.
+    Create a test of a given type with the given test name
 
     Args:
         test_name (str): Name of the test.
+        test_type (str): Type of the test. Currently supports
+            "Text", "Layout", "Screenshot" and "Ref""
         is_async (bool, optional): Whether it is an async test. Defaults to False.
     """
-    input_prefix = TEST_DIR / "Text" / "input" / test_name
-    input_dir = input_prefix.parent
-    input_file = input_prefix.with_suffix(".html")
 
-    expected_prefix = TEST_DIR / "Text" / "expected" / test_name
-    expected_dir = expected_prefix.parent
-    expected_file = expected_prefix.with_suffix(".txt")
+    input_prefix = TEST_DIR / test_type / "input" / test_name
+    input_file = input_prefix.with_suffix(".html")
+    input_dir = input_prefix.parent
+
+    output_prefix = TEST_DIR / test_type / "expected" / test_name
+    if test_type in ["Layout", "Text"]:
+        output_file = output_prefix.with_suffix(".txt")
+    else:
+        output_file = output_prefix.with_name(Path(test_name).stem + "-ref.html")
+    output_dir = output_prefix.parent
 
     # Create directories if they don't exist
     input_dir.mkdir(parents=True, exist_ok=True)
-    expected_dir.mkdir(parents=True, exist_ok=True)
+    output_dir.mkdir(parents=True, exist_ok=True)
 
     num_sub_levels = len(Path(test_name).parents) - 1
     path_to_include_js = "../" * num_sub_levels + "include.js"
 
-    # Create input and expected files
-    input_file.write_text(fR"""<!DOCTYPE html>
+    def generate_boilerplate():
+        """
+        return a tuple of strings with the input and
+        output boilerplate for a given test type
+        """
+
+        generic_boilerplate = R"""<!DOCTYPE html>
+<head>
+<style>
+</style>
+</head>
+<body>
+</body>
+"""
+
+        if test_type == "Text":
+            input_boilerplate = fR"""<!DOCTYPE html>
 <script src="{path_to_include_js}"></script>
 <script>
     {f"asyncTest(async (done)" if is_async else "test(()"} => {{
@@ -41,20 +62,60 @@ def create_text_test(test_name: str, is_async: bool = False) -> None:
     {f"    done();" if is_async else ""}
     }});
 </script>
-""")
-    expected_file.write_text("Expected println() output\n")
+"""
+            expected_boilerplate = "Expected println() output\n"
 
-    print(f"Text test '{Path(test_name).with_suffix('.html')}' created successfully.")
+        elif test_type == "Ref":
+            input_boilerplate = fR"""<!DOCTYPE html>
+<head>
+     <link rel="match" href="{"../" * num_sub_levels}../expected/{Path(test_name).with_suffix("")}-ref.html" />
+<style>
+</style>
+</head>
+<body>
+</body>
+"""
+
+            expected_boilerplate = f"Put equivalently rendering HTML for {test_name} here."
+
+        elif test_type == "Screenshot":
+            input_boilerplate = generic_boilerplate
+            expected_boilerplate = f"Put equivalently rendering HTML for {test_name} here."
+
+        # layout tests are async agnostic
+        elif test_type == "Layout":
+            input_boilerplate = generic_boilerplate
+            expected_boilerplate = f"""run
+ ./Meta/ladybird.sh run headless-browser --run-tests
+ "${{LADYBIRD_SOURCE_DIR}}/Tests/LibWeb" --rebaseline -f {input_file}
+to produce the expected output for this test
+"""
+            print("Delete <!DOCTYPE html> and replace it with <!--Quirks mode--> if test should run in quirks mode")
+
+        else:
+            # should be unreachable
+            raise ValueError(f"UNREACHABLE Invalid test type: {test_type}")
+
+        return (input_boilerplate, expected_boilerplate)
+
+    # Create input and expected files
+    input_boilerplate, expected_boilerplate = generate_boilerplate()
+    input_file.write_text(input_boilerplate)
+    output_file.write_text(expected_boilerplate)
+
+    print(f"{test_type} test '{Path(test_name).with_suffix('.html')}' created successfully.")
 
 
 def main():
+    supported_test_types = ["Ref", "Text", "Screenshot", "Layout"]
+
     parser = argparse.ArgumentParser(description="Create a new LibWeb Text test file.")
     parser.add_argument("test_name", type=str, help="Name of the test")
+    parser.add_argument("test_type", type=str, help="Type of the test", choices=supported_test_types)
     parser.add_argument("--async", action="store_true", help="Flag to indicate if it's an async test", dest="is_async")
     args = parser.parse_args()
 
-    # TODO: Add support for other test types: Layout and Ref
-    create_text_test(args.test_name, args.is_async)
+    create_test(args.test_name, args.test_type, args.is_async)
 
 
 if __name__ == "__main__":