Add support for quilt.mod.json5 (#150)

See:
- RFC: QuiltMC/rfcs#83
- Build tool impl: QuiltMC/quilt-loom#36, QuiltMC/quilt-loom#37
- Required loader PR: QuiltMC/quilt-loader#329

build.gradle

@@ -167,6 +167,9 @@ dependencies {
 	// Forge mods.toml parsing
 	implementation libs.night.config.toml
 
+	// quilt.mod.json5 parsing
+	implementation libs.jankson
+
 	// Testing
 	testImplementation(gradleTestKit())
 	testImplementation(testLibs.spock) {

gradle/libs.versions.toml

@@ -20,7 +20,7 @@ test-retry = "1.5.6"
 checkstyle = "10.17.0"
 codenarc = "3.4.0"
 
-# Forge libraries
+# Architectury libraries
 forge-installer-tools = "1.2.0"
 lorenz = "0.5.3"
 mcinjector = "3.8.0"
@@ -29,6 +29,7 @@ forge-diffpatch = "2.0.7"
 night-config = "3.6.6"
 datafixerupper = "6.0.8"
 at = "1.0.1"
+jankson = "1.2.3"
 
 [libraries]
 # Loom compile libraries
@@ -56,7 +57,7 @@ fabric-unpick-utils = { module = "net.fabricmc.unpick:unpick-format-utils", vers
 kotlin-gradle-plugin = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
 kotlin-metadata = { module = "org.jetbrains.kotlin:kotlin-metadata-jvm", version.ref = "kotlin" }
 
-# Forge support
+# Architectury
 forge-installer-tools = { module = "net.minecraftforge:installertools", version.ref = "forge-installer-tools" }
 lorenz = { module = "org.cadixdev:lorenz", version.ref = "lorenz" }
 mcinjector = { module = "de.oceanlabs.mcp:mcinjector", version.ref = "mcinjector" }
@@ -65,6 +66,7 @@ forge-diffpatch = { module = "net.minecraftforge:DiffPatch", version.ref = "forg
 night-config-toml = { module = "com.electronwill.night-config:toml", version.ref = "night-config" }
 datafixerupper = { module = "com.mojang:datafixerupper", version.ref = "datafixerupper" }
 at = { module = "dev.architectury:at", version.ref = "at" }
+jankson = { module = "blue.endless:jankson", version.ref = "jankson" }
 
 [plugins]
 kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }

src/main/java/dev/architectury/loom/metadata/ModMetadataFiles.java

@@ -2,12 +2,17 @@ package dev.architectury.loom.metadata;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
+import blue.endless.jankson.Jankson;
+import blue.endless.jankson.JsonElement;
+import blue.endless.jankson.JsonGrammar;
+import blue.endless.jankson.api.SyntaxError;
 import com.google.common.collect.ImmutableMap;
 import org.gradle.api.Project;
 import org.gradle.api.logging.Logger;
@@ -15,6 +20,7 @@ import org.gradle.api.logging.Logging;
 import org.gradle.api.tasks.SourceSet;
 import org.jetbrains.annotations.Nullable;
 
+import net.fabricmc.loom.util.ExceptionUtil;
 import net.fabricmc.loom.util.ZipUtils;
 import net.fabricmc.loom.util.gradle.SourceSetHelper;
 
@@ -25,6 +31,7 @@ public final class ModMetadataFiles {
 	private static final Logger LOGGER = Logging.getLogger(ModMetadataFiles.class);
 	private static final Map<String, Function<byte[], ModMetadataFile>> SINGLE_FILE_METADATA_TYPES = ImmutableMap.<String, Function<byte[], ModMetadataFile>>builder()
 			.put(QuiltModJson.FILE_NAME, QuiltModJson::of)
+			.put(QuiltModJson.JSON5_FILE_NAME, convertJson5ToJson(QuiltModJson::of))
 			.put(ArchitecturyCommonJson.FILE_NAME, ArchitecturyCommonJson::of)
 			.put(ModsToml.FILE_PATH, onError(ModsToml::of, "Could not load mods.toml", () -> new ErroringModMetadataFile("mods.toml")))
 			.put(ModsToml.NEOFORGE_FILE_PATH, onError(ModsToml::of, "Could not load neoforge.mods.toml", () -> new ErroringModMetadataFile("neoforge.mods.toml")))
@@ -41,6 +48,20 @@ public final class ModMetadataFiles {
 		};
 	}
 
+	private static <R> Function<byte[], R> convertJson5ToJson(Function<byte[], R> next) {
+		return bytes -> {
+			var text = new String(bytes, StandardCharsets.UTF_8);
+			Jankson jankson = Jankson.builder().build();
+			String json;
+			try {
+				json = jankson.fromJson(text, JsonElement.class).toJson(JsonGrammar.STRICT);
+			} catch (SyntaxError e) {
+				throw ExceptionUtil.createDescriptiveWrapper(RuntimeException::new, "Could not read JSON5 file", e);
+			}
+			return next.apply(json.getBytes(StandardCharsets.UTF_8));
+		};
+	}
+
 	/**
 	 * Reads the mod metadata file from a jar.
 	 *

src/main/java/dev/architectury/loom/metadata/QuiltModJson.java

@@ -25,6 +25,8 @@ import net.fabricmc.loom.util.function.CollectionUtil;
 
 public final class QuiltModJson implements JsonBackedModMetadataFile, SingleIdModMetadataFile {
 	public static final String FILE_NAME = "quilt.mod.json";
+	// See RFC 0083
+	public static final String JSON5_FILE_NAME = "quilt.mod.json5";
 	private static final Logger LOGGER = LoggerFactory.getLogger(QuiltModJson.class);
 	private static final String ACCESS_WIDENER_KEY = "access_widener";
 	private static final String MIXIN_KEY = "mixin";

src/main/java/net/fabricmc/loom/task/RemapJarTask.java

@@ -25,6 +25,7 @@
 package net.fabricmc.loom.task;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
@@ -34,8 +35,13 @@ import java.util.stream.Stream;
 
 import javax.inject.Inject;
 
+import blue.endless.jankson.Jankson;
+import blue.endless.jankson.JsonElement;
+import blue.endless.jankson.JsonGrammar;
+import blue.endless.jankson.api.SyntaxError;
 import com.google.gson.JsonObject;
 import dev.architectury.loom.extensions.ModBuildExtensions;
+import dev.architectury.loom.metadata.QuiltModJson;
 import org.gradle.api.artifacts.ConfigurationContainer;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileCollection;
@@ -72,6 +78,7 @@ import net.fabricmc.loom.task.service.MixinRefmapService;
 import net.fabricmc.loom.task.service.TinyRemapperService;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.ExceptionUtil;
+import net.fabricmc.loom.util.FileSystemUtil;
 import net.fabricmc.loom.util.ModPlatform;
 import net.fabricmc.loom.util.Pair;
 import net.fabricmc.loom.util.SidedClassVisitor;
@@ -280,6 +287,10 @@ public abstract class RemapJarTask extends AbstractRemapJarTask {
 					ModBuildExtensions.convertAwToAt(serviceFactory, getParameters().getAtAccessWideners().get(), outputFile, mappingsServiceOptions);
 				}
 
+				if (getParameters().getPlatform().get() == ModPlatform.QUILT) {
+					convertQmj5();
+				}
+
 				if (!getParameters().getPlatform().get().isForgeLike()) {
 					modifyJarManifest();
 				}
@@ -425,6 +436,31 @@ public abstract class RemapJarTask extends AbstractRemapJarTask {
 
 			ZipUtils.transformJson(JsonObject.class, outputFile, FabricModJsonFactory.FABRIC_MOD_JSON, FabricModJsonUtils::optimizeFmj);
 		}
+
+		private void convertQmj5() throws IOException {
+			byte[] bytes = ZipUtils.unpackNullable(outputFile, QuiltModJson.JSON5_FILE_NAME);
+			if (bytes == null) return;
+
+			if (ZipUtils.contains(outputFile, QuiltModJson.FILE_NAME)) {
+				throw new IllegalStateException("Output file contains both quilt.mod.json and quilt.mod.json5");
+			}
+
+			Jankson jankson = Jankson.builder().build();
+			JsonElement json;
+
+			try {
+				json = jankson.fromJson(new String(bytes, StandardCharsets.UTF_8), JsonElement.class);
+			} catch (SyntaxError e) {
+				throw ExceptionUtil.createDescriptiveWrapper(RuntimeException::new, "Could not read quilt.mod.json5", e);
+			}
+
+			String qmj = json.toJson(JsonGrammar.STRICT);
+
+			try (FileSystemUtil.Delegate fs = FileSystemUtil.getJarFileSystem(outputFile, false)) {
+				Files.delete(fs.getPath(QuiltModJson.JSON5_FILE_NAME));
+				Files.writeString(fs.getPath(QuiltModJson.FILE_NAME), qmj, StandardCharsets.UTF_8);
+			}
+		}
 	}
 
 	@Override

src/main/java/net/fabricmc/loom/task/launch/GenerateDLIConfigTask.java

@@ -216,7 +216,8 @@ public abstract class GenerateDLIConfigTask extends AbstractLoomTask {
 		if (quilt) {
 			launchConfig
 					.argument("client", "--version")
-					.argument("client", "Architectury Loom");
+					.argument("client", "Architectury Loom")
+					.property("loader.enable_quilt_mod_json5_in_dev_env", "true");
 		}
 
 		if (platform.isForgeLike()) {