Correctly handle IntelliJ runs for root project names with spaces (#52)

src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java

@@ -48,7 +48,6 @@
 import org.jetbrains.gradle.ext.Application;
 import org.jetbrains.gradle.ext.IdeaExtPlugin;
 import org.jetbrains.gradle.ext.JUnit;
-import org.jetbrains.gradle.ext.ModuleRef;
 import org.jetbrains.gradle.ext.ProjectSettings;
 import org.jetbrains.gradle.ext.RunConfigurationContainer;
 import org.slf4j.event.Level;
@@ -739,7 +738,7 @@ private static void addIntelliJRunConfiguration(Project project,
         if (!sourceSets.contains(sourceSet)) {
             throw new GradleException("Cannot use source set from another project for run " + run.getName());
         }
-        appRun.setModuleRef(new ModuleRef(project, sourceSet));
+        appRun.setModuleName(RunUtils.getIntellijModuleName(project, sourceSet));
         appRun.setWorkingDirectory(run.getGameDirectory().get().getAsFile().getAbsolutePath());
         appRun.setEnvs(run.getEnvironment().get());
 

src/main/java/net/neoforged/moddevgradle/internal/RunUtils.java

@@ -21,6 +21,7 @@
 import org.gradle.process.CommandLineArgumentProvider;
 import org.intellij.lang.annotations.Language;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.gradle.ext.ModuleRef;
 import org.slf4j.event.Level;
 import org.xml.sax.InputSource;
 
@@ -299,6 +300,25 @@ private static String evaluateXPath(File file, @Language("xpath") String express
             throw new UncheckedIOException("Failed to evaluate xpath " + expression + " on file " + file, e);
         }
     }
+
+    /**
+     * Convert a project and source set to an IntelliJ module name.
+     * Do not use {@link ModuleRef} as it does not correctly handle projects with a space in their name!
+     */
+    public static String getIntellijModuleName(Project project, SourceSet sourceSet) {
+        var moduleName = new StringBuilder();
+        // The `replace` call here is our bug fix compared to ModuleRef!
+        // The actual IDEA logic is more complicated, but this should cover the majority of use cases.
+        // See https://github.com/JetBrains/intellij-community/blob/a32fd0c588a6da11fd6d5d2fb0362308da3206f3/plugins/gradle/src/org/jetbrains/plugins/gradle/service/project/GradleProjectResolverUtil.java#L205
+        // which calls https://github.com/JetBrains/intellij-community/blob/a32fd0c588a6da11fd6d5d2fb0362308da3206f3/platform/util-rt/src/com/intellij/util/PathUtilRt.java#L120
+        moduleName.append(project.getRootProject().getName().replace(" ", "_"));
+        if (project != project.getRootProject()) {
+            moduleName.append(project.getPath().replaceAll(":", "."));
+        }
+        moduleName.append(".");
+        moduleName.append(sourceSet.getName());
+        return moduleName.toString();
+    }
 }
 
 record AssetProperties(String assetIndex, String assetsRoot) {