Merge remote-tracking branch 'FabricMC/dev/0.6' into dev/0.6-forge

19 files changed, 554 insertions, 215 deletions

diff --git a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
index f26decb3..8d7b1a6c 100644
--- a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
+++ b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
@@ -44,17 +44,20 @@ import com.google.gson.JsonObject;
 import org.cadixdev.lorenz.MappingSet;
 import org.cadixdev.mercury.Mercury;
 import org.gradle.api.Action;
+import org.gradle.api.NamedDomainObjectContainer;
 import org.gradle.api.Project;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.artifacts.Dependency;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.plugins.BasePluginConvention;
+import org.jetbrains.annotations.ApiStatus;
 import org.gradle.api.plugins.JavaPluginConvention;
 import org.gradle.api.tasks.SourceSet;
 import org.jetbrains.annotations.Nullable;
 
 import net.fabricmc.loom.api.decompilers.LoomDecompiler;
 import net.fabricmc.loom.configuration.LoomDependencyManager;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 import net.fabricmc.loom.configuration.processors.JarProcessor;
 import net.fabricmc.loom.configuration.processors.JarProcessorManager;
 import net.fabricmc.loom.configuration.providers.MinecraftProvider;
@@ -72,7 +75,6 @@ import net.fabricmc.loom.util.function.LazyBool;
 public class LoomGradleExtension {
 	private static final String FORGE_PROPERTY = "loom.forge";
 
-	public String runDir = "run";
 	public String refmapName;
 	public String loaderLaunchMethod;
 	public boolean remapMod = true;
@@ -111,6 +113,8 @@ public class LoomGradleExtension {
 		}
 	})));
 
+	private NamedDomainObjectContainer<RunConfigSettings> runs;
+
 	/**
 	 * Loom will generate a new genSources task (with a new name, based off of {@link LoomDecompiler#name()})
 	 * that uses the specified decompiler instead.
@@ -209,6 +213,8 @@ public class LoomGradleExtension {
 		this.autoGenIDERuns = isRootProject();
 		this.unmappedMods = project.files();
 		this.forge = new LazyBool(() -> Boolean.parseBoolean(Objects.toString(project.findProperty(FORGE_PROPERTY))));
+		this.runs = project.container(RunConfigSettings.class,
+				baseName -> new RunConfigSettings(project, baseName));
 	}
 
 	/**
@@ -384,7 +390,7 @@ public class LoomGradleExtension {
 
 	@Nullable
 	private Dependency getMixinDependency() {
-		return recurseProjects((p) -> {
+		return recurseProjects(p -> {
 			Set<Configuration> configs = new LinkedHashSet<>();
 			// check compile classpath first
 			Configuration possibleCompileClasspath = p.getConfigurations().findByName("compileClasspath");
@@ -401,11 +407,7 @@ public class LoomGradleExtension {
 					return true;
 				}
 
-				if (name.equalsIgnoreCase("sponge-mixin") && group.equalsIgnoreCase("net.fabricmc")) {
-					return true;
-				}
-
-				return false;
+				return name.equalsIgnoreCase("sponge-mixin") && group.equalsIgnoreCase("net.fabricmc");
 			});
 		});
 	}
@@ -561,4 +563,14 @@ public class LoomGradleExtension {
 	public List<LoomDecompiler> getDecompilers() {
 		return decompilers;
 	}
+
+	@ApiStatus.Experimental
+	public void runs(Action<NamedDomainObjectContainer<RunConfigSettings>> action) {
+		action.execute(runs);
+	}
+
+	@ApiStatus.Experimental
+	public NamedDomainObjectContainer<RunConfigSettings> getRuns() {
+		return runs;
+	}
 }
diff --git a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
index cb7be779..d315f75c 100644
--- a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
+++ b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
@@ -74,21 +74,6 @@ public final class CompileConfiguration {
 	}
 
 	public static void setupConfigurations(Project project) {
-		// Force add Mojang and Forge repositories
-		addMavenRepo(project, "Mojang", "https://libraries.minecraft.net/");
-		addMavenRepo(project, "Forge", "https://files.minecraftforge.net/maven/", repo -> {
-			repo.metadataSources(sources -> {
-				sources.mavenPom();
-
-				try {
-					MavenArtifactRepository.MetadataSources.class.getDeclaredMethod("ignoreGradleMetadataRedirection")
-							.invoke(sources);
-				} catch (Throwable ignored) {
-					// Method not available
-				}
-			});
-		});
-
 		Configuration modCompileClasspathConfig = project.getConfigurations().maybeCreate(Constants.Configurations.MOD_COMPILE_CLASSPATH);
 		modCompileClasspathConfig.setTransitive(true);
 		Configuration modCompileClasspathMappedConfig = project.getConfigurations().maybeCreate(Constants.Configurations.MOD_COMPILE_CLASSPATH_MAPPED);
@@ -219,6 +204,17 @@ public final class CompileConfiguration {
 			project1.getRepositories().maven(mavenArtifactRepository -> {
 				mavenArtifactRepository.setName("Forge");
 				mavenArtifactRepository.setUrl("https://files.minecraftforge.net/maven/");
+
+				mavenArtifactRepository.metadataSources(sources -> {
+					sources.mavenPom();
+
+					try {
+						MavenArtifactRepository.MetadataSources.class.getDeclaredMethod("ignoreGradleMetadataRedirection")
+								.invoke(sources);
+					} catch (Throwable ignored) {
+						// Method not available
+					}
+				});
 			});
 
 			project1.getRepositories().mavenCentral();
diff --git a/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java b/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
index 91c4ee9d..ae73c145 100644
--- a/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
+++ b/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
@@ -32,6 +32,7 @@ import java.io.StringWriter;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Set;
 import java.util.zip.ZipEntry;
 
@@ -88,6 +89,12 @@ public class AccessWidenerJarProcessor implements JarProcessor {
 		//Remap accessWidener if its not named, allows for AE's to be written in intermediary
 		if (!accessWidener.getNamespace().equals("named")) {
 			try {
+				List<String> validNamespaces = loomGradleExtension.getMappingsProvider().getMappings().getMetadata().getNamespaces();
+
+				if (!validNamespaces.contains(accessWidener.getNamespace())) {
+					throw new UnsupportedOperationException(String.format("Access Widener namespace '%s' is not a valid namespace, it must be one of: '%s'", accessWidener.getNamespace(), String.join(", ", validNamespaces)));
+				}
+
 				TinyRemapper tinyRemapper = loomGradleExtension.getMinecraftMappedProvider().getTinyRemapper(null, "official", "named");
 				loomGradleExtension.getMinecraftMappedProvider();
 				tinyRemapper.readClassPath(MinecraftMappedProvider.getRemapClasspath(project));
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
index 1e75b56b..eb85934a 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
@@ -31,7 +31,6 @@ import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
 import java.util.function.Supplier;
@@ -44,7 +43,6 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
-import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.gradle.api.Project;
 import org.gradle.api.tasks.SourceSet;
@@ -63,6 +61,7 @@ public class RunConfig {
 	public String ideaModuleName;
 	public String vscodeProjectName;
 	public String mainClass;
+	public String runDirIdeaUrl;
 	public String runDir;
 	public String vmArgs;
 	public String programArgs;
@@ -75,7 +74,7 @@ public class RunConfig {
 
 		this.addXml(root, "module", ImmutableMap.of("name", ideaModuleName));
 		this.addXml(root, "option", ImmutableMap.of("name", "MAIN_CLASS_NAME", "value", mainClass));
-		this.addXml(root, "option", ImmutableMap.of("name", "WORKING_DIRECTORY", "value", runDir));
+		this.addXml(root, "option", ImmutableMap.of("name", "WORKING_DIRECTORY", "value", runDirIdeaUrl));
 
 		if (!Strings.isNullOrEmpty(vmArgs)) {
 			this.addXml(root, "option", ImmutableMap.of("name", "VM_PARAMETERS", "value", vmArgs));
@@ -113,8 +112,8 @@ public class RunConfig {
 		return e;
 	}
 
-	private static String getIdeaModuleName(Project project) {
-		String module = project.getName() + ".main";
+	private static String getIdeaModuleName(Project project, SourceSet srcs) {
+		String module = project.getName() + "." + srcs.getName();
 
 		while ((project = project.getParent()) != null) {
 			module = project.getName() + "." + module;
@@ -126,13 +125,12 @@ public class RunConfig {
 	private static void populate(Project project, LoomGradleExtension extension, RunConfig runConfig, String mode) {
 		runConfig.configName += extension.isRootProject() ? "" : " (" + project.getPath() + ")";
 		runConfig.eclipseProjectName = project.getExtensions().getByType(EclipseModel.class).getProject().getName();
-		runConfig.ideaModuleName = getIdeaModuleName(project);
 		runConfig.vscodeProjectName = extension.isRootProject() ? "" : project.getPath();
-		runConfig.runDir = "file://$PROJECT_DIR$/" + extension.runDir;
 		runConfig.vmArgs = "";
+		runConfig.programArgs = "";
 
 		if ("launchwrapper".equals(extension.getLoaderLaunchMethod())) {
-			runConfig.mainClass = "net.minecraft.launchwrapper.Launch";
+			runConfig.mainClass = "net.minecraft.launchwrapper.Launch"; // TODO What about custom tweakers for run configs?
 			runConfig.programArgs += "--tweakClass " + ("client".equals(mode) ? Constants.LaunchWrapper.DEFAULT_FABRIC_CLIENT_TWEAKER : Constants.LaunchWrapper.DEFAULT_FABRIC_SERVER_TWEAKER);
 		} else {
 			runConfig.mainClass = "net.fabricmc.devlaunchinjector.Main";
@@ -186,50 +184,74 @@ public class RunConfig {
 		}
 	}
 
-	public static RunConfig clientRunConfig(Project project) {
-		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
-
-		RunConfig ideaClient = new RunConfig();
-		ideaClient.configName = "Minecraft Client";
-		ideaClient.programArgs = "";
-		populate(project, extension, ideaClient, "client");
-		ideaClient.vmArgs += getOSClientJVMArgs();
-		ideaClient.vmArgs += " -Dfabric.dli.main=" + getMainClass("client", extension);
-		ideaClient.vscodeBeforeRun = new ArrayList<>(extension.getTasksBeforeRun());
+	// Turns camelCase/PascalCase into Capital Case
+	// caseConversionExample -> Case Conversion Example
+	private static String capitalizeCamelCaseName(String name) {
+		if (name.length() == 0) {
+			return "";
+		}
 
-		return ideaClient;
+		return name.substring(0, 1).toUpperCase() + name.substring(1).replaceAll("([^A-Z])([A-Z])", "$1 $2");
 	}
 
-	public static RunConfig serverRunConfig(Project project) {
+	public static RunConfig runConfig(Project project, RunConfigSettings settings) {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
+		String name = settings.getName();
 
-		RunConfig ideaServer = new RunConfig();
-		ideaServer.configName = "Minecraft Server";
-		ideaServer.programArgs = "nogui ";
-		populate(project, extension, ideaServer, "server");
-		ideaServer.vmArgs += " -Dfabric.dli.main=" + getMainClass("server", extension);
-		ideaServer.vscodeBeforeRun = new ArrayList<>(extension.getTasksBeforeRun());
+		String configName = settings.getConfigName();
+		String mode = settings.getMode();
+		SourceSet sourceSet = settings.getSource(project);
 
-		return ideaServer;
-	}
+		String defaultMain = settings.getDefaultMainClass();
 
-	public static RunConfig dataRunConfig(Project project) {
-		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
+		if (defaultMain == null) {
+			throw new IllegalArgumentException("Run configuration '" + name + "' must specify 'defaultMainClass'");
+		}
 
-		RunConfig ideaServer = new RunConfig();
-		ideaServer.configName = "Generate Data";
-		ideaServer.programArgs = "";
-		populate(project, extension, ideaServer, "data");
-		ideaServer.vmArgs += " -Dfabric.dli.main=" + getMainClass("data", extension);
-		ideaServer.vscodeBeforeRun = new ArrayList<>(extension.getTasksBeforeRun());
+		if (configName == null) {
+			configName = "";
+			String srcName = sourceSet.getName();
 
-		return ideaServer;
-	}
+			if (!srcName.equals(SourceSet.MAIN_SOURCE_SET_NAME)) {
+				configName += capitalizeCamelCaseName(srcName) + " ";
+			}
+
+			configName += "Minecraft " + capitalizeCamelCaseName(name);
+		}
+
+		if (mode == null) {
+			mode = name;
+		}
+
+		String runDir = settings.getRunDir();
 
-	// This can be removed at somepoint, its not ideal but its the best solution I could thing of
-	public static boolean needsUpgrade(File file) throws IOException {
-		String contents = FileUtils.readFileToString(file, StandardCharsets.UTF_8);
-		return !(contents.contains("net.fabricmc.devlaunchinjector.Main"));
+		if (runDir == null) {
+			runDir = "run";
+		}
+
+		RunConfig runConfig = new RunConfig();
+		runConfig.configName = configName;
+		populate(project, extension, runConfig, mode);
+		runConfig.ideaModuleName = getIdeaModuleName(project, sourceSet);
+		runConfig.runDirIdeaUrl = "file://$PROJECT_DIR$/" + runDir;
+		runConfig.runDir = runDir;
+
+		// Custom parameters
+		for (String progArg : settings.getProgramArgs()) {
+			runConfig.programArgs += " " + progArg;
+		}
+
+		for (String vmArg : settings.getVmArgs()) {
+			runConfig.vmArgs += " " + vmArg;
+		}
+
+		runConfig.vmArgs += " -Dfabric.dli.main=" + getMainClass(mode, extension, defaultMain);
+
+		// Remove unnecessary leading/trailing whitespaces we might have generated
+		runConfig.programArgs = runConfig.programArgs.trim();
+		runConfig.vmArgs = runConfig.vmArgs.trim();
+
+		return runConfig;
 	}
 
 	public String fromDummy(String dummy) throws IOException {
@@ -243,6 +265,7 @@ public class RunConfig {
 		dummyConfig = dummyConfig.replace("%MAIN_CLASS%", mainClass);
 		dummyConfig = dummyConfig.replace("%ECLIPSE_PROJECT%", eclipseProjectName);
 		dummyConfig = dummyConfig.replace("%IDEA_MODULE%", ideaModuleName);
+		dummyConfig = dummyConfig.replace("%RUN_DIRECTORY%", runDir);
 		dummyConfig = dummyConfig.replace("%PROGRAM_ARGS%", programArgs.replaceAll("\"", "&quot;"));
 		dummyConfig = dummyConfig.replace("%VM_ARGS%", vmArgs.replaceAll("\"", "&quot;"));
 
@@ -276,11 +299,7 @@ public class RunConfig {
 		return "";
 	}
 
-	private static String getMainClass(String side, LoomGradleExtension extension) {
-		if (extension.isForge()) {
-			return "net.minecraftforge.userdev.LaunchTesting";
-		}
-
+	private static String getMainClass(String side, LoomGradleExtension extension, String defaultMainClass) {
 		JsonObject installerJson = extension.getInstallerJson();
 
 		if (installerJson != null && installerJson.has("mainClass")) {
@@ -306,7 +325,7 @@ public class RunConfig {
 			return "net.minecraft.launchwrapper.Launch";
 		}
 
-		return "net.fabricmc.loader.launch.knot.Knot" + side.substring(0, 1).toUpperCase(Locale.ROOT) + side.substring(1).toLowerCase(Locale.ROOT);
+		return defaultMainClass;
 	}
 
 	private static String encodeEscaped(String s) {
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
new file mode 100644
index 00000000..1a3ff178
--- /dev/null
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
@@ -0,0 +1,299 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2016, 2017, 2018 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.configuration.ide;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import org.gradle.api.Named;
+import org.gradle.api.Project;
+import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.tasks.SourceSet;
+import org.jetbrains.annotations.ApiStatus;
+
+import net.fabricmc.loom.LoomGradleExtension;
+import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.OperatingSystem;
+
+/**
+ * Experimental for now, please make sure to direct any suggests towards the github.
+ */
+@ApiStatus.Experimental
+public final class RunConfigSettings implements Named {
+	/**
+	 * Arguments for the JVM, such as system properties.
+	 */
+	private final List<String> vmArgs = new ArrayList<>();
+
+	/**
+	 * Arguments for the program's main class.
+	 */
+	private final List<String> programArgs = new ArrayList<>();
+
+	/**
+	 * The mode to run, which is the name of the run config in {@code fabric_installer.[method].json}.
+	 */
+	private String mode;
+
+	/**
+	 * The full name of the run configuration, i.e. 'Minecraft Client'.
+	 *
+	 * <p>By default this is determined from the base name.
+	 */
+	private String name;
+
+	/**
+	 * The default main class of the run configuration.
+	 *
+	 * <p>This can be overwritten in {@code fabric_installer.[method].json}. Note that this <em>doesn't</em> take
+	 * priority over the main class specified in the Fabric installer configuration.
+	 */
+	private String defaultMainClass;
+
+	/**
+	 * The source set getter, which obtains the source set from the given project.
+	 */
+	private Function<Project, SourceSet> source;
+
+	/**
+	 * The run directory for this configuration, relative to the root project directory.
+	 */
+	private String runDir;
+
+	/**
+	 * The base name of the run configuration, which is the name it is created with, i.e. 'client'
+	 */
+	private final String baseName;
+
+	private final Project project;
+	private final LoomGradleExtension extension;
+
+	public RunConfigSettings(Project project, String baseName) {
+		this.baseName = baseName;
+		this.project = project;
+		this.extension = project.getExtensions().getByType(LoomGradleExtension.class);
+
+		mode(baseName);
+		source("main");
+		runDir("run");
+	}
+
+	public Project getProject() {
+		return project;
+	}
+
+	public LoomGradleExtension getExtension() {
+		return extension;
+	}
+
+	@Override
+	public String getName() {
+		return baseName;
+	}
+
+	public List<String> getVmArgs() {
+		return vmArgs;
+	}
+
+	public List<String> getProgramArgs() {
+		return programArgs;
+	}
+
+	public String getMode() {
+		return mode;
+	}
+
+	public void setMode(String mode) {
+		this.mode = mode;
+	}
+
+	public String getConfigName() {
+		return name;
+	}
+
+	public void setConfigName(String name) {
+		this.name = name;
+	}
+
+	public String getDefaultMainClass() {
+		return defaultMainClass;
+	}
+
+	public void setDefaultMainClass(String defaultMainClass) {
+		this.defaultMainClass = defaultMainClass;
+	}
+
+	public String getRunDir() {
+		return runDir;
+	}
+
+	public void setRunDir(String runDir) {
+		this.runDir = runDir;
+	}
+
+	public SourceSet getSource(Project proj) {
+		return source.apply(proj);
+	}
+
+	public void setSource(SourceSet source) {
+		this.source = proj -> source;
+	}
+
+	public void setSource(Function<Project, SourceSet> sourceFn) {
+		this.source = sourceFn;
+	}
+
+	public void mode(String mode) {
+		setMode(mode);
+	}
+
+	public void name(String name) {
+		setConfigName(name);
+	}
+
+	public void defaultMainClass(String cls) {
+		setDefaultMainClass(cls);
+	}
+
+	public void runDir(String dir) {
+		setRunDir(dir);
+	}
+
+	public void vmArg(String arg) {
+		vmArgs.add(arg);
+	}
+
+	public void vmArgs(String... args) {
+		vmArgs.addAll(Arrays.asList(args));
+	}
+
+	public void vmArgs(Collection<String> args) {
+		vmArgs.addAll(args);
+	}
+
+	public void property(String name, String value) {
+		vmArg("-D" + name + "=" + value);
+	}
+
+	public void property(String name) {
+		vmArg("-D" + name);
+	}
+
+	public void properties(Map<String, String> props) {
+		props.forEach(this::property);
+	}
+
+	public void programArg(String arg) {
+		programArgs.add(arg);
+	}
+
+	public void programArgs(String... args) {
+		programArgs.addAll(Arrays.asList(args));
+	}
+
+	public void programArgs(Collection<String> args) {
+		programArgs.addAll(args);
+	}
+
+	public void source(SourceSet source) {
+		setSource(source);
+	}
+
+	public void source(String source) {
+		setSource(proj -> {
+			JavaPluginConvention conv = proj.getConvention().getPlugin(JavaPluginConvention.class);
+			return conv.getSourceSets().getByName(source);
+		});
+	}
+
+	/**
+	 * Add the {@code -XstartOnFirstThread} JVM argument when on OSX.
+	 */
+	public void startFirstThread() {
+		if (OperatingSystem.getOS().equalsIgnoreCase("osx")) {
+			vmArg("-XstartOnFirstThread");
+		}
+	}
+
+	/**
+	 * Removes the {@code nogui} argument for the server configuration. By default {@code nogui} is specified, this is
+	 * a convenient way to remove it if wanted.
+	 */
+	public void serverWithGui() {
+		programArgs.removeIf("nogui"::equals);
+	}
+
+	/**
+	 * Configure run config with the default client options.
+	 */
+	public void client() {
+		startFirstThread();
+		mode("client");
+		defaultMainClass(getExtension().isForge() ? Constants.ForgeUserDev.LAUNCH_TESTING : Constants.Knot.KNOT_CLIENT);
+	}
+
+	/**
+	 * Configure run config with the default server options.
+	 */
+	public void server() {
+		programArg("nogui");
+		mode("server");
+		defaultMainClass(getExtension().isForge() ? Constants.ForgeUserDev.LAUNCH_TESTING : Constants.Knot.KNOT_SERVER);
+	}
+
+	/**
+	 * Configure run config with the default server options.
+	 */
+	public void data() {
+		mode("data");
+		defaultMainClass(getExtension().isForge() ? Constants.ForgeUserDev.LAUNCH_TESTING : Constants.Knot.KNOT_SERVER);
+	}
+
+	/**
+	 * Copies settings from another run configuration.
+	 */
+	public void inherit(RunConfigSettings parent) {
+		vmArgs.addAll(0, parent.vmArgs);
+		programArgs.addAll(0, parent.programArgs);
+
+		mode = parent.mode;
+		name = parent.name;
+		defaultMainClass = parent.defaultMainClass;
+		source = parent.source;
+	}
+
+	public void makeRunDir() {
+		File file = new File(getProject().getRootDir(), runDir);
+
+		if (!file.exists()) {
+			file.mkdir();
+		}
+	}
+}
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java b/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
index 5cf04f9b..c531cee8 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
@@ -50,12 +50,6 @@ public class SetupIntelijRunConfigs {
 		} catch (IOException e) {
 			throw new RuntimeException("Failed to generate run configs", e);
 		}
-
-		File runDir = new File(project.getRootDir(), extension.runDir);
-
-		if (!runDir.exists()) {
-			runDir.mkdirs();
-		}
 	}
 
 	private static void generate(Project project) throws IOException {
@@ -72,31 +66,23 @@ public class SetupIntelijRunConfigs {
 
 		File projectDir = rootProject.file(".idea");
 		File runConfigsDir = new File(projectDir, "runConfigurations");
-		File clientRunConfigs = new File(runConfigsDir, "Minecraft_Client" + projectPath + ".xml");
-		File serverRunConfigs = new File(runConfigsDir, "Minecraft_Server" + projectPath + ".xml");
-		File dataRunConfigs = new File(runConfigsDir, "Minecraft_Data" + projectPath + ".xml");
 
 		if (!runConfigsDir.exists()) {
 			runConfigsDir.mkdirs();
 		}
 
-		String clientRunConfig = RunConfig.clientRunConfig(project).fromDummy("idea_run_config_template.xml");
-		String serverRunConfig = RunConfig.serverRunConfig(project).fromDummy("idea_run_config_template.xml");
-
-		if (!clientRunConfigs.exists() || RunConfig.needsUpgrade(clientRunConfigs)) {
-			FileUtils.writeStringToFile(clientRunConfigs, clientRunConfig, StandardCharsets.UTF_8);
-		}
-
-		if (!serverRunConfigs.exists() || RunConfig.needsUpgrade(serverRunConfigs)) {
-			FileUtils.writeStringToFile(serverRunConfigs, serverRunConfig, StandardCharsets.UTF_8);
-		}
+		for (RunConfigSettings settings : extension.getRuns()) {
+			RunConfig config = RunConfig.runConfig(project, settings);
+			String name = config.configName.replaceAll("[^a-zA-Z0-9$_]", "_");
 
-		if (extension.isDataGenEnabled()) {
-			String dataRunConfig = RunConfig.dataRunConfig(project).fromDummy("idea_run_config_template.xml");
+			File runConfigs = new File(runConfigsDir, name + projectPath + ".xml");
+			String runConfigXml = config.fromDummy("idea_run_config_template.xml");
 
-			if (!dataRunConfigs.exists() || RunConfig.needsUpgrade(dataRunConfigs)) {
-				FileUtils.writeStringToFile(dataRunConfigs, dataRunConfig, StandardCharsets.UTF_8);
+			if (!runConfigs.exists()) {
+				FileUtils.writeStringToFile(runConfigs, runConfigXml, StandardCharsets.UTF_8);
 			}
+
+			settings.makeRunDir();
 		}
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProvider.java
index a36e7355..8d0a8d5e 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProvider.java
@@ -31,8 +31,6 @@ import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.Optional;
 import java.util.function.Consumer;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 import java.util.zip.ZipError;
 
 import com.google.common.io.Files;
@@ -178,13 +176,11 @@ public class MinecraftProvider extends DependencyProvider {
 			} else {
 				getProject().getLogger().debug("Downloading Minecraft {} manifest", minecraftVersion);
 
-				String url = optionalVersion.get().url;
-				// Find the sha1 of the json from the url, return true if it matches the local json
-				Pattern sha1Pattern = Pattern.compile("\\b[0-9a-f]{5,40}\\b");
-				Matcher matcher = sha1Pattern.matcher(url);
+				ManifestVersion.Versions version = optionalVersion.get();
+				String url = version.url;
 
-				if (matcher.find()) {
-					HashedDownloadUtil.downloadIfInvalid(new URL(url), minecraftJson, matcher.group(), getProject().getLogger(), true);
+				if (version.sha1 != null) {
+					HashedDownloadUtil.downloadIfInvalid(new URL(url), minecraftJson, version.sha1, getProject().getLogger(), true);
 				} else {
 					// Use the etag if no hash found from url
 					DownloadUtil.downloadIfChanged(new URL(url), minecraftJson, getProject().getLogger());
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/ManifestVersion.java b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/ManifestVersion.java
index 4cc2e33e..8ab01007 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/ManifestVersion.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/ManifestVersion.java
@@ -31,6 +31,6 @@ public class ManifestVersion {
 	public List<Versions> versions = new ArrayList<>();
 
 	public static class Versions {
-		public String id, url;
+		public String id, url, sha1;
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/assets/MinecraftAssetsProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/assets/MinecraftAssetsProvider.java
index ee4d9448..b1913436 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/assets/MinecraftAssetsProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/assets/MinecraftAssetsProvider.java
@@ -30,23 +30,23 @@ import java.io.FileWriter;
 import java.io.IOException;
 import java.net.URL;
 import java.util.Deque;
+import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
-import au.com.bytecode.opencsv.CSVReader;
-import au.com.bytecode.opencsv.CSVWriter;
 import com.google.common.base.Stopwatch;
 import com.google.common.hash.Hashing;
 import com.google.common.io.Files;
 import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
 import org.gradle.api.GradleException;
 import org.gradle.api.Project;
 
 import net.fabricmc.loom.LoomGradleExtension;
+import net.fabricmc.loom.LoomGradlePlugin;
 import net.fabricmc.loom.configuration.providers.MinecraftProvider;
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftVersionInfo;
 import net.fabricmc.loom.util.Checksum;
@@ -70,7 +70,7 @@ public class MinecraftAssetsProvider {
 		}
 
 		File assetsInfo = new File(assets, "indexes" + File.separator + assetIndex.getFabricId(minecraftProvider.getMinecraftVersion()) + ".json");
-		File checksumInfo = new File(assets, "checksum" + File.separator + minecraftProvider.getMinecraftVersion() + ".csv");
+		File checksumInfo = new File(assets, "checksum" + File.separator + minecraftProvider.getMinecraftVersion() + ".json");
 
 		if (!assetsInfo.exists() || !Checksum.equals(assetsInfo, assetIndex.sha1)) {
 			project.getLogger().lifecycle(":downloading asset index");
@@ -88,50 +88,46 @@ public class MinecraftAssetsProvider {
 			}
 		}
 
-		Map<String, AssetChecksumInfo> checksumInfos = new ConcurrentHashMap<>();
+		Gson gson = new Gson();
+		Map<String, String> checksumInfos = new HashMap<>();
 
 		if (checksumInfo.exists()) {
-			try (CSVReader reader = new CSVReader(new FileReader(checksumInfo))) {
-				String[] strings;
-
-				while ((strings = reader.readNext()) != null) {
-					checksumInfos.put(strings[0], new AssetChecksumInfo(strings[1], Long.parseLong(strings[2])));
-				}
+			try (FileReader reader = new FileReader(checksumInfo)) {
+				checksumInfos.putAll(gson.fromJson(reader, new TypeToken<Map<String, String>>() {
+				}.getType()));
 			}
 		}
 
-		project.getLogger().lifecycle(":downloading assets...");
-
 		Deque<ProgressLogger> loggers = new ConcurrentLinkedDeque<>();
 		ExecutorService executor = Executors.newFixedThreadPool(Math.min(10, Math.max(Runtime.getRuntime().availableProcessors() / 2, 1)));
+		int toDownload = 0;
 
 		AssetIndex index;
 
 		try (FileReader fileReader = new FileReader(assetsInfo)) {
-			index = new Gson().fromJson(fileReader, AssetIndex.class);
+			index = gson.fromJson(fileReader, AssetIndex.class);
 		}
 
 		Stopwatch stopwatch = Stopwatch.createStarted();
 
 		Map<String, AssetObject> parent = index.getFileMap();
 
-		parent.entrySet().parallelStream().forEach(entry -> {
+		for (Map.Entry<String, AssetObject> entry : parent.entrySet()) {
 			AssetObject object = entry.getValue();
 			String sha1 = object.getHash();
 			String filename = "objects" + File.separator + sha1.substring(0, 2) + File.separator + sha1;
 			File file = new File(assets, filename);
-			long localFileLength = !file.exists() ? -1L : file.length();
 
-			AssetChecksumInfo localFileChecksum = localFileLength == -1L ? null : checksumInfos.computeIfAbsent(entry.getKey(), path -> {
+			String localFileChecksum = !file.exists() ? null : checksumInfos.computeIfAbsent(entry.getKey(), path -> {
 				try {
-					return new AssetChecksumInfo(Files.asByteSource(file).hash(Hashing.sha1()).toString(), localFileLength);
+					return Files.asByteSource(file).hash(Hashing.sha1()).toString();
 				} catch (IOException e) {
 					e.printStackTrace();
 					return null;
 				}
 			});
 
-			if (localFileChecksum == null || localFileChecksum.length != localFileLength || !localFileChecksum.sha1.equals(sha1)) {
+			if (LoomGradlePlugin.refreshDeps || localFileChecksum == null || !localFileChecksum.equals(sha1)) {
 				if (offline) {
 					if (file.exists()) {
 						project.getLogger().warn("Outdated asset " + entry.getKey());
@@ -139,6 +135,7 @@ public class MinecraftAssetsProvider {
 						throw new GradleException("Asset " + entry.getKey() + " not found at " + file.getAbsolutePath());
 					}
 				} else {
+					toDownload++;
 					executor.execute(() -> {
 						ProgressLogger progressLogger;
 
@@ -167,12 +164,8 @@ public class MinecraftAssetsProvider {
 							throw new RuntimeException("Failed to download: " + assetName, e);
 						}
 
-						try {
-							if (localFileChecksum == null) {
-								checksumInfos.put(entry.getKey(), new AssetChecksumInfo(Files.asByteSource(file).hash(Hashing.sha1()).toString(), file.length()));
-							}
-						} catch (IOException e) {
-							throw new RuntimeException("Failed to save checksum: " + assetName, e);
+						if (localFileChecksum == null) {
+							checksumInfos.put(entry.getKey(), sha1);
 						}
 
 						//Give this logger back
@@ -180,22 +173,18 @@ public class MinecraftAssetsProvider {
 					});
 				}
 			}
-		});
+		}
 
 		project.getLogger().info("Took " + stopwatch.stop() + " to iterate " + parent.size() + " asset index.");
 
-		{
-			checksumInfo.getParentFile().mkdirs();
+		if (toDownload > 0) {
+			project.getLogger().lifecycle(":downloading " + toDownload + " asset" + (toDownload == 1 ? "" : "s") + "...");
+		}
+
+		checksumInfo.getParentFile().mkdirs();
 
-			try (CSVWriter writer = new CSVWriter(new FileWriter(checksumInfo))) {
-				checksumInfos.forEach((path, info) -> {
-					writer.writeNext(new String[] {
-							path,
-							info.sha1,
-							String.valueOf(info.length)
-					});
-				});
-			}
+		try (FileWriter writer = new FileWriter(checksumInfo)) {
+			gson.toJson(checksumInfos, writer);
 		}
 
 		//Wait for the assets to all download
@@ -211,14 +200,4 @@ public class MinecraftAssetsProvider {
 
 		loggers.forEach(ProgressLogger::completed);
 	}
-
-	private static class AssetChecksumInfo {
-		public final String sha1;
-		public long length;
-
-		AssetChecksumInfo(String sha1, long length) {
-			this.sha1 = sha1;
-			this.length = length;
-		}
-	}
 }
diff --git a/src/main/java/net/fabricmc/loom/task/AbstractRunTask.java b/src/main/java/net/fabricmc/loom/task/AbstractRunTask.java
index 551bd58a..5f47cc17 100644
--- a/src/main/java/net/fabricmc/loom/task/AbstractRunTask.java
+++ b/src/main/java/net/fabricmc/loom/task/AbstractRunTask.java
@@ -45,6 +45,9 @@ public abstract class AbstractRunTask extends JavaExec {
 		super();
 		setGroup("fabric");
 		this.configProvider = config;
+
+		classpath(getProject().getConfigurations().getByName("runtimeClasspath"));
+		classpath(this.getProject().getExtensions().getByType(LoomGradleExtension.class).getUnmappedModCollection());
 	}
 
 	@Override
@@ -53,9 +56,6 @@ public abstract class AbstractRunTask extends JavaExec {
 			config = configProvider.apply(getProject());
 		}
 
-		classpath(getProject().getConfigurations().getByName("runtimeClasspath"));
-		classpath(this.getProject().getExtensions().getByType(LoomGradleExtension.class).getUnmappedModCollection());
-
 		List<String> argsSplit = new ArrayList<>();
 		String[] args = config.programArgs.split(" ");
 		int partPos = -1;
@@ -85,8 +85,7 @@ public abstract class AbstractRunTask extends JavaExec {
 		}
 
 		args(argsSplit);
-		LoomGradleExtension extension = this.getProject().getExtensions().getByType(LoomGradleExtension.class);
-		setWorkingDir(new File(getProject().getRootDir(), extension.runDir));
+		setWorkingDir(new File(getProject().getRootDir(), config.runDir));
 		environment(config.envVariables);
 
 		super.exec();
diff --git a/src/main/java/net/fabricmc/loom/task/GenEclipseRunsTask.java b/src/main/java/net/fabricmc/loom/task/GenEclipseRunsTask.java
index 0896c4bf..1f93ef0b 100644
--- a/src/main/java/net/fabricmc/loom/task/GenEclipseRunsTask.java
+++ b/src/main/java/net/fabricmc/loom/task/GenEclipseRunsTask.java
@@ -32,39 +32,29 @@ import org.apache.commons.io.FileUtils;
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.plugins.ide.eclipse.model.EclipseModel;
 
+import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 
 public class GenEclipseRunsTask extends AbstractLoomTask {
 	@TaskAction
 	public void genRuns() throws IOException {
 		EclipseModel eclipseModel = getProject().getExtensions().getByType(EclipseModel.class);
-		File clientRunConfigs = new File(getProject().getRootDir(), eclipseModel.getProject().getName() + "_client.launch");
-		File serverRunConfigs = new File(getProject().getRootDir(), eclipseModel.getProject().getName() + "_server.launch");
+		LoomGradleExtension extension = getExtension();
 		File dataRunConfigs = new File(getProject().getRootDir(), eclipseModel.getProject().getName() + "_data.launch");
 
-		String clientRunConfig = RunConfig.clientRunConfig(getProject()).fromDummy("eclipse_run_config_template.xml");
-		String serverRunConfig = RunConfig.serverRunConfig(getProject()).fromDummy("eclipse_run_config_template.xml");
+		for (RunConfigSettings settings : extension.getRuns()) {
+			String name = settings.getName();
 
-		if (!clientRunConfigs.exists() || RunConfig.needsUpgrade(clientRunConfigs)) {
-			FileUtils.writeStringToFile(clientRunConfigs, clientRunConfig, StandardCharsets.UTF_8);
-		}
-
-		if (!serverRunConfigs.exists() || RunConfig.needsUpgrade(serverRunConfigs)) {
-			FileUtils.writeStringToFile(serverRunConfigs, serverRunConfig, StandardCharsets.UTF_8);
-		}
+			File configs = new File(getProject().getRootDir(), eclipseModel.getProject().getName() + "_" + name + ".launch");
+			RunConfig configInst = RunConfig.runConfig(getProject(), settings);
+			String config = configInst.fromDummy("eclipse_run_config_template.xml");
 
-		if (getExtension().isDataGenEnabled()) {
-			String dataRunConfig = RunConfig.dataRunConfig(getProject()).fromDummy("eclipse_run_config_template.xml");
-
-			if (!dataRunConfigs.exists() || RunConfig.needsUpgrade(dataRunConfigs)) {
-				FileUtils.writeStringToFile(dataRunConfigs, dataRunConfig, StandardCharsets.UTF_8);
+			if (!configs.exists()) {
+				FileUtils.writeStringToFile(configs, config, StandardCharsets.UTF_8);
 			}
-		}
-
-		File runDir = new File(getProject().getRootDir(), getExtension().runDir);
 
-		if (!runDir.exists()) {
-			runDir.mkdirs();
+			settings.makeRunDir();
 		}
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/task/GenIdeaProjectTask.java b/src/main/java/net/fabricmc/loom/task/GenIdeaProjectTask.java
index cd5fbe52..8ad3586b 100644
--- a/src/main/java/net/fabricmc/loom/task/GenIdeaProjectTask.java
+++ b/src/main/java/net/fabricmc/loom/task/GenIdeaProjectTask.java
@@ -46,6 +46,7 @@ import org.xml.sax.SAXException;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 
 public class GenIdeaProjectTask extends AbstractLoomTask {
 	@TaskAction
@@ -82,11 +83,9 @@ public class GenIdeaProjectTask extends AbstractLoomTask {
 			throw new RuntimeException("Failed to generate IntelliJ run configurations (runManager was not found)");
 		}
 
-		runManager.appendChild(RunConfig.clientRunConfig(project).genRuns(runManager));
-		runManager.appendChild(RunConfig.serverRunConfig(project).genRuns(runManager));
-
-		if (extension.isDataGenEnabled()) {
-			runManager.appendChild(RunConfig.dataRunConfig(project).genRuns(runManager));
+		for (RunConfigSettings settings : getExtension().getRuns()) {
+			runManager.appendChild(RunConfig.runConfig(project, settings).genRuns(runManager));
+			settings.makeRunDir();
 		}
 
 		TransformerFactory transformerFactory = TransformerFactory.newInstance();
@@ -96,11 +95,5 @@ public class GenIdeaProjectTask extends AbstractLoomTask {
 		transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 		transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
 		transformer.transform(source, result);
-
-		File runDir = new File(getProject().getRootDir(), extension.runDir);
-
-		if (!runDir.exists()) {
-			runDir.mkdirs();
-		}
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/task/GenVsCodeProjectTask.java b/src/main/java/net/fabricmc/loom/task/GenVsCodeProjectTask.java
index d1fe52b9..e6ea643f 100644
--- a/src/main/java/net/fabricmc/loom/task/GenVsCodeProjectTask.java
+++ b/src/main/java/net/fabricmc/loom/task/GenVsCodeProjectTask.java
@@ -43,6 +43,7 @@ import org.gradle.api.tasks.TaskAction;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 
 // Recommended vscode plugins:
 // https://marketplace.visualstudio.com/items?itemName=redhat.java
@@ -94,11 +95,9 @@ public class GenVsCodeProjectTask extends AbstractLoomTask {
 			launch = new VsCodeLaunch();
 		}
 
-		launch.add(RunConfig.clientRunConfig(project));
-		launch.add(RunConfig.serverRunConfig(project));
-
-		if (extension.isDataGenEnabled()) {
-			launch.add(RunConfig.dataRunConfig(project));
+		for (RunConfigSettings settings : extension.getRuns()) {
+			launch.add(RunConfig.runConfig(project, settings));
+			settings.makeRunDir();
 		}
 
 		String json = gson.toJson(launch);
@@ -109,12 +108,6 @@ public class GenVsCodeProjectTask extends AbstractLoomTask {
 			throw new RuntimeException("Failed to write launch.json", e);
 		}
 
-		File runDir = new File(project.getRootDir(), extension.runDir);
-
-		if (!runDir.exists()) {
-			runDir.mkdirs();
-		}
-
 		VsCodeTasks tasks;
 
 		if (tasksJson.exists()) {
@@ -181,7 +174,7 @@ public class GenVsCodeProjectTask extends AbstractLoomTask {
 		public String type = "java";
 		public String name;
 		public String request = "launch";
-		public String cwd = "${workspaceFolder}/run";
+		public String cwd;
 		public String console = "internalConsole";
 		public boolean stopOnEntry = false;
 		public String mainClass;
@@ -197,6 +190,7 @@ public class GenVsCodeProjectTask extends AbstractLoomTask {
 			this.mainClass = runConfig.mainClass;
 			this.vmArgs = runConfig.vmArgs;
 			this.args = runConfig.programArgs;
+			this.cwd = "${workspaceFolder}/" + runConfig.runDir;
 			this.projectName = runConfig.vscodeProjectName;
 			this.env.putAll(runConfig.envVariables);
 			this.tasksBeforeRun.addAll(runConfig.vscodeBeforeRun);
diff --git a/src/main/java/net/fabricmc/loom/task/LoomTasks.java b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
index e17ad8e6..0fdd28cd 100644
--- a/src/main/java/net/fabricmc/loom/task/LoomTasks.java
+++ b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
@@ -29,6 +29,7 @@ import org.gradle.api.tasks.TaskContainer;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.api.decompilers.LoomDecompiler;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 import net.fabricmc.loom.decompilers.fernflower.FabricFernFlowerDecompiler;
 
 public final class LoomTasks {
@@ -40,7 +41,7 @@ public final class LoomTasks {
 
 		tasks.register("migrateMappings", MigrateMappingsTask.class, t -> {
 			t.setDescription("Migrates mappings to a new version.");
-			t.getOutputs().upToDateWhen((o) -> false);
+			t.getOutputs().upToDateWhen(o -> false);
 		});
 
 		tasks.register("remapJar", RemapJarTask.class, t -> {
@@ -84,21 +85,22 @@ public final class LoomTasks {
 	private static void registerRunTasks(TaskContainer tasks, Project project) {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
 
-		tasks.register("runClient", RunClientTask.class, t -> {
-			t.setDescription("Starts a development version of the Minecraft client.");
-			t.dependsOn("downloadAssets");
-			t.setGroup("fabric");
-		});
+		extension.getRuns().create("client", RunConfigSettings::client);
+		extension.getRuns().create("server", RunConfigSettings::server);
 
-		tasks.register("runServer", RunServerTask.class, t -> {
-			t.setDescription("Starts a development version of the Minecraft server.");
-			t.setGroup("fabric");
+		project.afterEvaluate(p -> {
+			if (extension.isDataGenEnabled()) {
+				extension.getRuns().create("data", RunConfigSettings::data);
+			}
 		});
 
 		project.afterEvaluate(p -> {
-			if (extension.isDataGenEnabled()) {
-				tasks.register("runData", RunDataTask.class, t -> {
-					t.setDescription("Starts a development version of the Minecraft data.");
+			for (RunConfigSettings config : extension.getRuns()) {
+				String configName = config.getName();
+				String taskName = "run" + configName.substring(0, 1).toUpperCase() + configName.substring(1);
+
+				tasks.register(taskName, RunGameTask.class, config).configure(t -> {
+					t.setDescription("Starts the '" + config.getConfigName() + "' run configuration");
 					t.setGroup("fabric");
 				});
 			}
@@ -108,9 +110,9 @@ public final class LoomTasks {
 	private static void registerDecompileTasks(TaskContainer tasks, Project project) {
 		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
 
-		project.afterEvaluate((p) -> {
+		project.afterEvaluate(p -> {
 			for (LoomDecompiler decompiler : extension.getDecompilers()) {
-				String taskName = (decompiler instanceof FabricFernFlowerDecompiler) ? "genSources" : "genSourcesWith" + decompiler.name();
+				String taskName = decompiler instanceof FabricFernFlowerDecompiler ? "genSources" : "genSourcesWith" + decompiler.name();
 				// decompiler will be passed to the constructor of GenerateSourcesTask
 				tasks.register(taskName, GenerateSourcesTask.class, decompiler);
 			}
diff --git a/src/main/java/net/fabricmc/loom/task/RunClientTask.java b/src/main/java/net/fabricmc/loom/task/RunClientTask.java
index de0cc377..0bfaca0c 100644
--- a/src/main/java/net/fabricmc/loom/task/RunClientTask.java
+++ b/src/main/java/net/fabricmc/loom/task/RunClientTask.java
@@ -24,10 +24,15 @@
 
 package net.fabricmc.loom.task;
 
+import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
 
+@Deprecated // Replaced by RunGameTask
 public class RunClientTask extends AbstractRunTask {
 	public RunClientTask() {
-		super(RunConfig::clientRunConfig);
+		super(project -> {
+			LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
+			return RunConfig.runConfig(project, extension.getRuns().getByName("client"));
+		});
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/task/RunDataTask.java b/src/main/java/net/fabricmc/loom/task/RunDataTask.java
index 01f62884..fbb80951 100644
--- a/src/main/java/net/fabricmc/loom/task/RunDataTask.java
+++ b/src/main/java/net/fabricmc/loom/task/RunDataTask.java
@@ -24,10 +24,15 @@
 
 package net.fabricmc.loom.task;
 
+import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
 
+@Deprecated // Replaced by RunGameTask
 public class RunDataTask extends AbstractRunTask {
 	public RunDataTask() {
-		super(RunConfig::dataRunConfig);
+		super(project -> {
+			LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
+			return RunConfig.runConfig(project, extension.getRuns().getByName("data"));
+		});
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/task/RunGameTask.java b/src/main/java/net/fabricmc/loom/task/RunGameTask.java
new file mode 100644
index 00000000..f82352a0
--- /dev/null
+++ b/src/main/java/net/fabricmc/loom/task/RunGameTask.java
@@ -0,0 +1,37 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2016, 2017, 2018 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.task;
+
+import javax.inject.Inject;
+
+import net.fabricmc.loom.configuration.ide.RunConfig;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
+
+public class RunGameTask extends AbstractRunTask {
+	@Inject
+	public RunGameTask(RunConfigSettings settings) {
+		super(proj -> RunConfig.runConfig(proj, settings));
+	}
+}
diff --git a/src/main/java/net/fabricmc/loom/task/RunServerTask.java b/src/main/java/net/fabricmc/loom/task/RunServerTask.java
index 977b65c7..aa9fc94a 100644
--- a/src/main/java/net/fabricmc/loom/task/RunServerTask.java
+++ b/src/main/java/net/fabricmc/loom/task/RunServerTask.java
@@ -24,10 +24,15 @@
 
 package net.fabricmc.loom.task;
 
+import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.ide.RunConfig;
 
+@Deprecated // Replaced by RunGameTask
 public class RunServerTask extends AbstractRunTask {
 	public RunServerTask() {
-		super(RunConfig::serverRunConfig);
+		super(project -> {
+			LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
+			return RunConfig.runConfig(project, extension.getRuns().getByName("client"));
+		});
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/util/Constants.java b/src/main/java/net/fabricmc/loom/util/Constants.java
index eb37930e..0ff48728 100644
--- a/src/main/java/net/fabricmc/loom/util/Constants.java
+++ b/src/main/java/net/fabricmc/loom/util/Constants.java
@@ -136,4 +136,19 @@ public class Constants {
 		private LaunchWrapper() {
 		}
 	}
+
+	public static final class Knot {
+		public static final String KNOT_CLIENT = "net.fabricmc.loader.launch.knot.KnotClient";
+		public static final String KNOT_SERVER = "net.fabricmc.loader.launch.knot.KnotServer";
+
+		private Knot() {
+		}
+	}
+	
+	public static final class ForgeUserDev {
+		public static final String LAUNCH_TESTING = "net.minecraftforge.userdev.LaunchTesting";
+
+		private ForgeUserDev() {
+		}
+	}
 }