Read data generation modid from FMJ by default. And code cleanup. (#1008

)

* Read data generation modid from FMJ by default. And code cleanup.

Closes #999

* Fix #1000

src/main/java/net/fabricmc/loom/configuration/FabricApiExtension.java

@@ -25,6 +25,7 @@
 package net.fabricmc.loom.configuration;
 
 import java.io.File;
+import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.util.Collections;
 import java.util.HashMap;
@@ -55,6 +56,8 @@
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.util.download.DownloadException;
+import net.fabricmc.loom.util.fmj.FabricModJson;
+import net.fabricmc.loom.util.fmj.FabricModJsonFactory;
 import net.fabricmc.loom.util.gradle.SourceSetHelper;
 
 public abstract class FabricApiExtension {
@@ -136,14 +139,10 @@ public void configureDataGeneration(Action<DataGenerationSettings> action) {
 		});
 
 		if (settings.getCreateSourceSet().get()) {
-			if (!settings.getModId().isPresent()) {
-				throw new IllegalStateException("DataGenerationSettings.getModId() must be set when using split sources.");
-			}
-
 			SourceSetContainer sourceSets = SourceSetHelper.getSourceSets(getProject());
 
 			// Create the new datagen sourceset, depend on the main sourceset.
-			sourceSets.create(DATAGEN_SOURCESET_NAME, sourceSet -> {
+			SourceSet dataGenSourceSet = sourceSets.create(DATAGEN_SOURCESET_NAME, sourceSet -> {
 				sourceSet.setCompileClasspath(
 							sourceSet.getCompileClasspath()
 								.plus(mainSourceSet.getOutput())
@@ -158,6 +157,20 @@ public void configureDataGeneration(Action<DataGenerationSettings> action) {
 				extendsFrom(getProject(), sourceSet.getRuntimeClasspathConfigurationName(), mainSourceSet.getRuntimeClasspathConfigurationName());
 			});
 
+			settings.getModId().convention(getProject().provider(() -> {
+				try {
+					final FabricModJson fabricModJson = FabricModJsonFactory.createFromSourceSetsNullable(dataGenSourceSet);
+
+					if (fabricModJson == null) {
+						throw new RuntimeException("Could not find a fabric.mod.json file in the data source set or a value for DataGenerationSettings.getModId()");
+					}
+
+					return fabricModJson.getId();
+				} catch (IOException e) {
+					throw new org.gradle.api.UncheckedIOException("Failed to read mod id from the datagen source set.", e);
+				}
+			}));
+
 			extension.getMods().create(settings.getModId().get(), mod -> {
 				// Create a classpath group for this mod. Assume that the main sourceset is already in a group.
 				mod.sourceSet(DATAGEN_SOURCESET_NAME);
@@ -168,7 +181,7 @@ public void configureDataGeneration(Action<DataGenerationSettings> action) {
 
 		if (settings.getCreateRunConfiguration().get()) {
 			extension.getRunConfigs().create("datagen", run -> {
-				run.name("Data Generation");
+				run.setConfigName("Data Generation");
 				run.inherit(extension.getRunConfigs().getByName("server"));
 
 				run.property("fabric-api.datagen");

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java

@@ -25,12 +25,14 @@
 package net.fabricmc.loom.extension;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.Set;
 
 import org.gradle.api.Action;
 import org.gradle.api.NamedDomainObjectContainer;
 import org.gradle.api.NamedDomainObjectList;
 import org.gradle.api.Project;
+import org.gradle.api.UncheckedIOException;
 import org.gradle.api.artifacts.Dependency;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.RegularFileProperty;
@@ -65,6 +67,8 @@
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftSourceSets;
 import net.fabricmc.loom.task.GenerateSourcesTask;
 import net.fabricmc.loom.util.DeprecationHelper;
+import net.fabricmc.loom.util.fmj.FabricModJson;
+import net.fabricmc.loom.util.fmj.FabricModJsonFactory;
 import net.fabricmc.loom.util.gradle.SourceSetHelper;
 
 /**
@@ -88,8 +92,6 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 	private final Property<Boolean> splitEnvironmentalSourceSet;
 	private final InterfaceInjectionExtensionAPI interfaceInjectionExtension;
 
-	private final ModVersionParser versionParser;
-
 	private final NamedDomainObjectContainer<RunConfigSettings> runConfigs;
 	private final NamedDomainObjectContainer<DecompilerOptions> decompilers;
 	private final NamedDomainObjectContainer<ModSettings> mods;
@@ -124,8 +126,6 @@ protected LoomGradleExtensionApiImpl(Project project, LoomFiles directories) {
 		this.intermediateMappingsProvider = project.getObjects().property(IntermediateMappingsProvider.class);
 		this.intermediateMappingsProvider.finalizeValueOnRead();
 
-		this.versionParser = new ModVersionParser(project);
-
 		this.deprecationHelper = new DeprecationHelper.ProjectBased(project);
 
 		this.runConfigs = project.container(RunConfigSettings.class,
@@ -252,7 +252,17 @@ public SetProperty<String> getKnownIndyBsms() {
 
 	@Override
 	public String getModVersion() {
-		return versionParser.getModVersion();
+		try {
+			final FabricModJson fabricModJson = FabricModJsonFactory.createFromSourceSetsNullable(SourceSetHelper.getMainSourceSet(getProject()));
+
+			if (fabricModJson == null) {
+				throw new RuntimeException("Could not find a fabric.mod.json file in the main sourceset");
+			}
+
+			return fabricModJson.getModVersion();
+		} catch (IOException e) {
+			throw new UncheckedIOException("Failed to read mod version from main sourceset.", e);
+		}
 	}
 
 	@Override

src/main/java/net/fabricmc/loom/util/fmj/FabricModJson.java

@@ -50,6 +50,10 @@ public String getId() {
 		return readString(jsonObject, "id");
 	}
 
+	public String getModVersion() {
+		return readString(jsonObject, "version");
+	}
+
 	@Nullable
 	public abstract JsonElement getCustom(String key);
 

src/test/groovy/net/fabricmc/loom/test/unit/fmj/FabricModJsonV0Test.groovy

@@ -62,6 +62,7 @@ class FabricModJsonV0Test extends Specification {
 		def fmj = FabricModJsonFactory.create(JSON_OBJECT, mockSource)
 		then:
 		fmj.version == 0
+		fmj.modVersion == "1.0.0"
 	}
 
 	def "id"() {

src/test/groovy/net/fabricmc/loom/test/unit/fmj/FabricModJsonV1Test.groovy

@@ -69,6 +69,7 @@ class FabricModJsonV1Test extends Specification {
 		def fmj = FabricModJsonFactory.create(JSON_OBJECT, mockSource)
 		then:
 		fmj.version == 1
+		fmj.modVersion == "1.0.0"
 	}
 
 	def "id"() {

src/test/groovy/net/fabricmc/loom/test/unit/fmj/FabricModJsonV2Test.groovy

@@ -83,6 +83,7 @@ class FabricModJsonV2Test extends Specification {
 		def fmj = FabricModJsonFactory.create(JSON_OBJECT, mockSource)
 		then:
 		fmj.version == 2
+		fmj.modVersion == "1.0.0"
 	}
 
 	def "id"() {