Add Loader support for quilt.mod.json5

src/main/java/org/quiltmc/loader/impl/discovery/ClasspathModCandidateFinder.java

@@ -56,6 +56,7 @@ public static void findCandidatesStatic(ModAdder out) {
 		if (QuiltLauncherBase.getLauncher().isDevelopment()) {
 			Map<Path, List<Path>> pathGroups = getPathGroups();
 			try {
+				findCandidates("quilt.mod.json5", pathGroups, out);
 				findCandidates("quilt.mod.json", pathGroups, out);
 				findCandidates("fabric.mod.json", pathGroups, out);
 			} catch (IOException e) {
@@ -84,21 +85,27 @@ private static void findCandidates(String metadataName, Map<Path, List<Path>> pa
 				Path path = LoaderUtil.normalizeExistingPath(UrlUtil.getCodeSource(url, metadataName));
 				List<Path> paths = pathGroups.get(path);
 
-				if (paths == null) {
-                    if (!url.getProtocol().equals("jar")) {
-						if (!pathGroups.isEmpty()) {
-							// path groups are enabled, warn for misconfiguration
-							Log.error(LogCategory.DISCOVERY,"Mod at path " + url + " lacks a class path group! Make sure the loom 'mods' block " +
-									"is configured correctly!");
+				// If this is specifically reading for quilt.mod.json files, we check against QMJ5s as well
+				// This is so we can ignore QMJs from mods that already have a QMJ5
+				if (metadataName.equals("quilt.mod.json") && Files.isRegularFile(path.resolve("quilt.mod.json5"))) {
+					Log.debug(LogCategory.DISCOVERY, "Ignoring quilt.mod.json from mod at path %s that already has a quilt.mod.json5", path);
+				} else {
+					if (paths == null) {
+						if (!url.getProtocol().equals("jar")) {
+							if (!pathGroups.isEmpty()) {
+								// path groups are enabled, warn for misconfiguration
+								Log.error(LogCategory.DISCOVERY,"Mod at path " + url + " lacks a class path group! Make sure the loom 'mods' block " +
+										"is configured correctly!");
+							}
+
+							Log.error(LogCategory.DISCOVERY, "Mod at path %s is not included in the loom 'mods' block! " +
+									"This will be an error in a future version of Loader!", path);
 						}
 
-						Log.error(LogCategory.DISCOVERY, "Mod at path %s is not included in the loom 'mods' block! " +
-								"This will be an error in a future version of Loader!", path);
-                    }
-
-                    out.addMod(Collections.singletonList(path));
-				} else {
-					out.addMod(paths);
+						out.addMod(Collections.singletonList(path));
+					} else {
+						out.addMod(paths);
+					}
 				}
 			} catch (UrlConversionException e) {
 				Log.debug(LogCategory.DISCOVERY, "Error determining location for %s from %s", metadataName, url, e);

src/main/java/org/quiltmc/loader/impl/metadata/qmj/ModMetadataReader.java

@@ -71,7 +71,12 @@ public static InternalModMetadata read(InputStream json) throws IOException, Par
 	public static InternalModMetadata read(InputStream json, Path path, QuiltPluginManager manager, PluginGuiTreeNode warningNode) throws IOException, ParseException {
 		JsonLoaderValue value;
 
-		try (JsonReader reader = JsonReader.json(new InputStreamReader(json, StandardCharsets.UTF_8))) {
+		try (JsonReader reader = JsonReader.json5(new InputStreamReader(json, StandardCharsets.UTF_8))) {
+			// Only use the reader as a JSON5 one if we're dealing with a JSON5 file
+			if (!path.toString().endsWith(".json5")) {
+				reader.setStrictJson();
+			}
+
 			// Root must be an object
 			if (reader.peek() != JsonToken.BEGIN_OBJECT) {
 				throw new ParseException(reader, "A quilt.mod.json must have an object at the root");

src/main/java/org/quiltmc/loader/impl/plugin/quilt/StandardQuiltPlugin.java

@@ -280,12 +280,86 @@ private ModLoadOption[] scan0(Path root, QuiltLoaderIcon fileIcon, ModLocation l
 		PluginGuiTreeNode guiNode) throws IOException {
 
 		Path qmj = root.resolve("quilt.mod.json");
-		if (!FasterFiles.isRegularFile(qmj)) {
+		Path qmj5 = root.resolve("quilt.mod.json5");
+		Path usedQmj = qmj;
+
+		if (FasterFiles.isRegularFile(qmj5)) {
+			if (QuiltLoader.isDevelopmentEnvironment()) {
+				if (Boolean.parseBoolean(System.getProperty(SystemProperties.ENABLE_QUILT_MOD_JSON5_IN_DEV_ENV))) {
+					if (FasterFiles.exists(qmj)) {
+						QuiltLoaderText title = QuiltLoaderText.translate("gui.text.qmj_qmj5_coexistence.title");
+						QuiltDisplayedError error = context().reportError(title);
+						String describedPath = context().manager().describePath(usedQmj);
+						error.appendReportText(
+								"A coexistence of 'quilt.mod.json5' and 'quilt.mod.json' has been detected at " + describedPath,
+								"These metadata files cannot coexist with each other due to their conflicting purposes!"
+						);
+						error.appendDescription(
+								QuiltLoaderText.translate("gui.text.qmj_qmj5_coexistence.desc.0"),
+								QuiltLoaderText.translate("gui.text.qmj_qmj5_coexistence.desc.1"),
+								QuiltLoaderText.translate("gui.text.qmj_qmj5_coexistence.desc.2", describedPath)
+						);
+						context().manager().getRealContainingFile(root).ifPresent(real ->
+								error.addFileViewButton(real)
+										.icon(QuiltLoaderGui.iconJarFile().withDecoration(QuiltLoaderGui.iconQuilt()))
+						);
+
+						guiNode.addChild(QuiltLoaderText.translate("gui.text.qmj_qmj5_coexistence"));
+						return null;
+					} else {
+						usedQmj = qmj5;
+					}
+				} else {
+					QuiltLoaderText title = QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled.title");
+					QuiltDisplayedError error = context().reportError(title);
+					String describedPath = context().manager().describePath(usedQmj);
+					error.appendReportText(
+							"Attempted to read a 'quilt.mod.json5' file at " + describedPath + " without the support being enabled!",
+							"If regenerating your run configurations doesn't fix this issue, then your build system doesn't support 'quilt.mod.json5' files!"
+					);
+					error.appendDescription(
+							QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled.desc.0"),
+							QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled.desc.1"),
+							QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled.desc.2"),
+							QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled.desc.3", describedPath)
+					);
+					context().manager().getRealContainingFile(root).ifPresent(real ->
+							error.addFileViewButton(real)
+									.icon(QuiltLoaderGui.iconJarFile().withDecoration(QuiltLoaderGui.iconQuilt()))
+					);
+
+					guiNode.addChild(QuiltLoaderText.translate("gui.text.qmj5_in_dev_env_not_enabled"));
+					return null;
+				}
+			} else {
+				QuiltLoaderText title = QuiltLoaderText.translate("gui.text.qmj5_on_production.title");
+				QuiltDisplayedError error = context().reportError(title);
+				String describedPath = context().manager().describePath(usedQmj);
+				error.appendReportText(
+						"An attempt to read a 'quilt.mod.json5' file was detected: " + describedPath,
+						"'quilt.mod.json5' files can't be used outside of a development environment without converting to a 'quilt.mod.json' file!"
+				);
+				error.appendDescription(
+						QuiltLoaderText.translate("gui.text.qmj5_on_production.desc.0"),
+						QuiltLoaderText.translate("gui.text.qmj5_on_production.desc.1"),
+						QuiltLoaderText.translate("gui.text.qmj5_on_production.desc.2", describedPath)
+				);
+				context().manager().getRealContainingFile(root).ifPresent(real ->
+						error.addFileViewButton(real)
+								.icon(QuiltLoaderGui.iconJarFile().withDecoration(QuiltLoaderGui.iconQuilt()))
+				);
+
+				guiNode.addChild(QuiltLoaderText.translate("gui.text.qmj5_on_production"));
+				return null;
+			}
+		}
+
+		if (!FasterFiles.isRegularFile(usedQmj)) {
 			return null;
 		}
 
 		try {
-			InternalModMetadata meta = ModMetadataReader.read(qmj, context().manager(), guiNode);
+			InternalModMetadata meta = ModMetadataReader.read(usedQmj, context().manager(), guiNode);
 
 			Path from = root;
 			if (isZip) {
@@ -330,7 +404,7 @@ private ModLoadOption[] scan0(Path root, QuiltLoaderIcon fileIcon, ModLocation l
 				"gui.text.invalid_metadata.title", "quilt.mod.json", parse.getMessage()
 			);
 			QuiltDisplayedError error = context().reportError(title);
-			String describedPath = context().manager().describePath(qmj);
+			String describedPath = context().manager().describePath(usedQmj);
 			error.appendReportText("Invalid 'quilt.mod.json' metadata file:" + describedPath);
 			error.appendDescription(QuiltLoaderText.translate("gui.text.invalid_metadata.desc.0", describedPath));
 			error.appendThrowable(parse);

src/main/java/org/quiltmc/loader/impl/util/SystemProperties.java

@@ -93,7 +93,7 @@ private SystemProperties() {}
 	public static final String LOG_CACHE_KEY_CHANGES = "loader.transform_cache.log_changed_keys";
 	// enable useTempFile in ZipFileSystem, reduces memory usage when writing transform cache at the cost of speed
 	public static final String USE_ZIPFS_TEMP_FILE = "loader.zipfs.use_temp_file";
-	public static final String DISABLE_BEACON = "loader.disable_beacon";
+	public static final String ENABLE_QUILT_MOD_JSON5_IN_DEV_ENV = "loader.enable_quilt_mod_json5_in_dev_env";
 	public static final String DEBUG_DUMP_FILESYSTEM_CONTENTS = "loader.debug.filesystem.dump_contents";
 	public static final String ALWAYS_DEFER_FILESYSTEM_OPERATIONS = "loader.workaround.defer_all_filesystem_operations";
 	public static final String DISABLE_QUILT_CLASS_PATH_CUSTOM_TABLE = "loader.quilt_class_path.disable_custom_table";

src/main/resources/lang/quilt_loader.properties

@@ -86,6 +86,22 @@ gui.error.zerobytezip.desc.0=Try deleting the file and downloading it again.
 gui.text.invalid_metadata=Invalid Metadata: %s
 gui.text.invalid_metadata.title=Unable to read %s: %s
 gui.text.invalid_metadata.desc.0=From %s
+gui.text.qmj5_on_production=Unconverted 'quilt.mod.json5' found
+gui.text.qmj5_on_production.title=Attempted to read an unconverted 'quilt.mod.json5' file
+gui.text.qmj5_on_production.desc.0=An attempt to read a 'quilt.mod.json5' file was detected!
+gui.text.qmj5_on_production.desc.1='quilt.mod.json5' files can't be used outside a development environment without converting to a 'quilt.mod.json' file!
+gui.text.qmj5_on_production.desc.2=From %s
+gui.text.qmj_qmj5_coexistence=Coexistence of conflicting Quilt metadata found
+gui.text.qmj_qmj5_coexistence.title=Detected the coexistence of conflicting metadata!
+gui.text.qmj_qmj5_coexistence.desc.0=A coexistence of 'quilt.mod.json5' and 'quilt.mod.json' has been detected.
+gui.text.qmj_qmj5_coexistence.desc.1=These metadata files cannot coexist with each other due to their conflicting purposes!
+gui.text.qmj_qmj5_coexistence.desc.2=From %s
+gui.text.qmj5_in_dev_env_not_enabled=Found a 'quilt.mod.json5' file without support enabled!
+gui.text.qmj5_in_dev_env_not_enabled.title=Found a 'quilt.mod.json5' file without support enabled!
+gui.text.qmj5_in_dev_env_not_enabled.desc.0=The Loader support for 'quilt.mod.json5' hasn't been enabled!
+gui.text.qmj5_in_dev_env_not_enabled.desc.1=If regenerating your run configurations doesn't fix this issue,
+gui.text.qmj5_in_dev_env_not_enabled.desc.2=then your build system doesn't support 'quilt.mod.json5' files!
+gui.text.qmj5_in_dev_env_not_enabled.desc.3=From %s
 error.unhandled_solver=Complex solver error; see the crash report for more information
 error.unhandled_solver.desc=Please try updating quilt-loader to see if an update can describe this.\nOr report this to the quilt-loader project so this can be fixed.
 error.unhandled_solver.desc.rule_n= \n \nRule %s (%s):