Meta: Replace GenerateCSSEnvironmentVariable with a python generator

Author: https://github.com/AtkinsSJ
Commit: https://github.com/LadybirdBrowser/ladybird/commit/f6a3ff388b3
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/9083

Meta/Generators/generate_libweb_css_environment_variables.py

@@ -0,0 +1,157 @@
+#!/usr/bin/env python3
+
+# Copyright (c) 2025-2026, Sam Atkins <sam@ladybird.org>
+# Copyright (c) 2026-present, the Ladybird developers.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+
+import argparse
+import json
+import sys
+
+from pathlib import Path
+from typing import TextIO
+
+sys.path.append(str(Path(__file__).resolve().parent.parent))
+
+from Utils.utils import title_casify
+from Utils.utils import underlying_type_for_enum
+
+
+def verify_alphabetical(data: dict, path: str) -> None:
+    most_recent_name = ""
+    for name in data:
+        if name < most_recent_name:
+            print(
+                f"`{name}` is in the wrong position in `{path}`. Please keep this list alphabetical!", file=sys.stderr
+            )
+            sys.exit(1)
+        most_recent_name = name
+
+
+def write_header_file(out: TextIO, environment_variables: dict) -> None:
+    underlying_type = underlying_type_for_enum(len(environment_variables))
+    out.write(f"""
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+#include <LibWeb/CSS/ValueType.h>
+
+namespace Web::CSS {{
+
+enum class EnvironmentVariable : {underlying_type} {{
+""")
+
+    for name in environment_variables:
+        out.write(f"    {title_casify(name)},\n")
+
+    out.write("""
+};
+
+Optional<EnvironmentVariable> environment_variable_from_string(StringView);
+StringView to_string(EnvironmentVariable);
+
+ValueType environment_variable_type(EnvironmentVariable);
+u32 environment_variable_dimension_count(EnvironmentVariable);
+}
+""")
+
+
+def write_implementation_file(out: TextIO, environment_variables: dict) -> None:
+    out.write("""
+#include <LibWeb/CSS/EnvironmentVariable.h>
+
+namespace Web::CSS {
+
+Optional<EnvironmentVariable> environment_variable_from_string(StringView string)
+{
+""")
+    for name in environment_variables:
+        out.write(f"""
+    if (string.equals_ignoring_ascii_case("{name}"sv))
+        return EnvironmentVariable::{title_casify(name)};
+""")
+
+    out.write("""
+
+    return {};
+}
+
+StringView to_string(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+""")
+
+    for name in environment_variables:
+        out.write(f"""
+    case EnvironmentVariable::{title_casify(name)}:
+        return "{name}"sv;
+""")
+
+    out.write("""
+    }
+    VERIFY_NOT_REACHED();
+}
+
+ValueType environment_variable_type(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+""")
+
+    for name, variable in environment_variables.items():
+        value_type = variable["type"].strip("<>")
+        out.write(f"""
+    case EnvironmentVariable::{title_casify(name)}:
+        return ValueType::{title_casify(value_type)};
+""")
+
+    out.write("""
+    }
+    VERIFY_NOT_REACHED();
+}
+
+u32 environment_variable_dimension_count(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+""")
+
+    for name, variable in environment_variables.items():
+        out.write(f"""
+    case EnvironmentVariable::{title_casify(name)}:
+        return {variable["dimensions"]};
+""")
+
+    out.write("""
+    }
+    VERIFY_NOT_REACHED();
+}
+
+}
+""")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Generate CSS EnvironmentVariable", add_help=False)
+    parser.add_argument("--help", action="help", help="Show this help message and exit")
+    parser.add_argument("-h", "--header", required=True, help="Path to the EnvironmentVariable header file to generate")
+    parser.add_argument(
+        "-c", "--implementation", required=True, help="Path to the EnvironmentVariable implementation file to generate"
+    )
+    parser.add_argument("-j", "--json", required=True, help="Path to the JSON file to read from")
+    args = parser.parse_args()
+
+    with open(args.json, "r", encoding="utf-8") as input_file:
+        environment_variables = json.load(input_file)
+
+    verify_alphabetical(environment_variables, args.json)
+
+    with open(args.header, "w", encoding="utf-8") as output_file:
+        write_header_file(output_file, environment_variables)
+
+    with open(args.implementation, "w", encoding="utf-8") as output_file:
+        write_implementation_file(output_file, environment_variables)
+
+
+if __name__ == "__main__":
+    main()