LibWeb+CodeGenerators: Generate EnvironmentVariable enum and functions

Author: https://github.com/AtkinsSJ
Commit: 7b30c94fcf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5736
Reviewed-by: https://github.com/kalenikaliaksandr

Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateCSSEnvironmentVariable.cpp

@@ -0,0 +1,197 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "GeneratorUtil.h"
+#include <AK/SourceGenerator.h>
+#include <LibCore/ArgsParser.h>
+#include <LibMain/Main.h>
+
+ErrorOr<void> generate_header_file(JsonObject const& environment_variables, Core::File& file);
+ErrorOr<void> generate_implementation_file(JsonObject const& environment_variables, Core::File& file);
+
+ErrorOr<int> ladybird_main(Main::Arguments arguments)
+{
+    StringView generated_header_path;
+    StringView generated_implementation_path;
+    StringView json_path;
+
+    Core::ArgsParser args_parser;
+    args_parser.add_option(generated_header_path, "Path to the EnvironmentVariable header file to generate", "generated-header-path", 'h', "generated-header-path");
+    args_parser.add_option(generated_implementation_path, "Path to the EnvironmentVariable implementation file to generate", "generated-implementation-path", 'c', "generated-implementation-path");
+    args_parser.add_option(json_path, "Path to the JSON file to read from", "json-path", 'j', "json-path");
+    args_parser.parse(arguments);
+
+    auto read_json_object = [](auto& path) -> ErrorOr<JsonObject> {
+        auto json = TRY(read_entire_file_as_json(path));
+        VERIFY(json.is_object());
+
+        // Check we're in alphabetical order
+        String most_recent_name;
+        json.as_object().for_each_member([&](auto& name, auto&) {
+            if (name < most_recent_name) {
+                warnln("`{}` is in the wrong position in `{}`. Please keep this list alphabetical!", name, path);
+                VERIFY_NOT_REACHED();
+            }
+            most_recent_name = name;
+        });
+
+        return json.as_object();
+    };
+
+    auto environment_variables = TRY(read_json_object(json_path));
+
+    auto generated_header_file = TRY(Core::File::open(generated_header_path, Core::File::OpenMode::Write));
+    auto generated_implementation_file = TRY(Core::File::open(generated_implementation_path, Core::File::OpenMode::Write));
+
+    TRY(generate_header_file(environment_variables, *generated_header_file));
+    TRY(generate_implementation_file(environment_variables, *generated_implementation_file));
+
+    return 0;
+}
+
+ErrorOr<void> generate_header_file(JsonObject const& environment_variables, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    generator.set("environment_variable_underlying_type", underlying_type_for_enum(environment_variables.size()));
+
+    generator.append(R"~~~(
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+#include <LibWeb/CSS/ValueType.h>
+
+namespace Web::CSS {
+
+enum class EnvironmentVariable : @environment_variable_underlying_type@ {
+)~~~");
+
+    environment_variables.for_each_member([&](auto& name, JsonValue const&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name:titlecase", title_casify(name));
+        member_generator.appendln("    @name:titlecase@,");
+    });
+    generator.append(R"~~~(
+};
+
+Optional<EnvironmentVariable> environment_variable_from_string(StringView);
+StringView to_string(EnvironmentVariable);
+
+ValueType environment_variable_type(EnvironmentVariable);
+u32 environment_variable_dimension_count(EnvironmentVariable);
+}
+)~~~");
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}
+
+ErrorOr<void> generate_implementation_file(JsonObject const& environment_variables, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    generator.append(R"~~~(
+#include <LibWeb/CSS/EnvironmentVariable.h>
+
+namespace Web::CSS {
+
+Optional<EnvironmentVariable> environment_variable_from_string(StringView string)
+{
+)~~~");
+    environment_variables.for_each_member([&](auto& name, JsonValue const&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+
+        member_generator.append(R"~~~(
+    if (string.equals_ignoring_ascii_case("@name@"sv))
+        return EnvironmentVariable::@name:titlecase@;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+
+    return {};
+}
+
+StringView to_string(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+)~~~");
+
+    environment_variables.for_each_member([&](auto& name, JsonValue const&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+
+        member_generator.append(R"~~~(
+    case EnvironmentVariable::@name:titlecase@:
+        return "@name@"sv;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+    }
+    VERIFY_NOT_REACHED();
+}
+
+ValueType environment_variable_type(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+)~~~");
+
+    environment_variables.for_each_member([&](auto& name, JsonValue const& value) {
+        auto& variable = value.as_object();
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+
+        auto value_type = MUST(variable.get_string("type"sv)->trim("<>"sv));
+        member_generator.set("value_type:titlecase", title_casify(value_type));
+
+        member_generator.append(R"~~~(
+    case EnvironmentVariable::@name:titlecase@:
+        return ValueType::@value_type:titlecase@;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+    }
+    VERIFY_NOT_REACHED();
+}
+
+u32 environment_variable_dimension_count(EnvironmentVariable environment_variable)
+{
+    switch (environment_variable) {
+)~~~");
+
+    environment_variables.for_each_member([&](auto& name, JsonValue const& value) {
+        auto& variable = value.as_object();
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+        member_generator.set("dimension_count", String::number(variable.get_u32("dimensions"sv).value()));
+
+        member_generator.append(R"~~~(
+    case EnvironmentVariable::@name:titlecase@:
+        return @dimension_count@;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+    }
+    VERIFY_NOT_REACHED();
+}
+
+}
+)~~~");
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}