Correctly handle when built-in configuration is missing / was removed

Fixes #66

Author: AB-xdev

src/main/java/software/xdev/pmd/model/config/ConfigurationLocationFactory.java

@@ -2,6 +2,7 @@
 
 import java.util.Collections;
 import java.util.Map;
+import java.util.Optional;
 import java.util.WeakHashMap;
 
 import org.jetbrains.annotations.NotNull;
@@ -11,6 +12,7 @@
 import software.xdev.pmd.external.org.apache.shiro.lang.util.SoftHashMap;
 import software.xdev.pmd.model.config.bundled.BundledConfig;
 import software.xdev.pmd.model.config.bundled.BundledConfigurationLocation;
+import software.xdev.pmd.model.config.bundled.UnknownBundledConfigurationLocation;
 import software.xdev.pmd.model.config.file.FileConfigurationLocation;
 import software.xdev.pmd.model.config.file.RelativeFileConfigurationLocation;
 
@@ -65,7 +67,9 @@ record CreateCacheKey(
 				{
 					case LOCAL_FILE -> new FileConfigurationLocation(project, id);
 					case PROJECT_RELATIVE -> new RelativeFileConfigurationLocation(project, id);
-					case BUNDLED -> new BundledConfigurationLocation(BundledConfig.fromId(id), project);
+					case BUNDLED -> Optional.ofNullable(BundledConfig.fromId(id))
+						.map(c -> new BundledConfigurationLocation(c, project))
+						.orElseGet(() -> new UnknownBundledConfigurationLocation(id, project));
 				};
 
 				configurationLocation.setLocation(location);

src/main/java/software/xdev/pmd/model/config/bundled/BundledConfig.java

@@ -10,6 +10,7 @@
 import java.util.stream.Collectors;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import com.intellij.openapi.application.ApplicationManager;
 
@@ -29,19 +30,15 @@ public final class BundledConfig
 
 	private final String description;
 
-	private final String path;
-	
 	private BundledConfig(
 		final int sortOrder,
 		@NotNull final String id,
-		@NotNull final String description,
-		@NotNull final String path)
+		@NotNull final String description)
 	{
 		this.sortOrder = sortOrder;
 		this.id = id;
 		this.location = BUNDLED_LOCATION;
 		this.description = description;
-		this.path = path;
 	}
 
 	public int getSortOrder()
@@ -66,24 +63,26 @@ public String getDescription()
 		return this.description;
 	}
 
-	@NotNull
-	public String getPath()
-	{
-		return this.path;
-	}
-	
 	public boolean matches(@NotNull final ConfigurationLocation configurationLocation)
 	{
 		return configurationLocation.getType() == ConfigurationType.BUNDLED
 			&& Objects.equals(configurationLocation.getLocation(), this.location)
 			&& Objects.equals(configurationLocation.getDescription(), this.description);
 	}
 
+	private static final AtomicInteger UNKNOWN_COUNTER = new AtomicInteger(1000);
+	
 	@NotNull
+	public static BundledConfig createUnknownDummy(@NotNull final String id)
+	{
+		return new BundledConfig(UNKNOWN_COUNTER.getAndIncrement(), id, "UNKNOWN: " + id);
+	}
+	
+	@Nullable
 	public static BundledConfig fromId(@NotNull final String id)
 	{
 		initAllIfRequired();
-		return Objects.requireNonNull(all.get(id), "Failed to find id " + id);
+		return all.get(id);
 	}
 
 	public static Collection<BundledConfig> getAllBundledConfigs()
@@ -114,8 +113,7 @@ private static void initAllIfRequired()
 				e.getKey() + "-" + Arrays.stream(e.getValue().split("/"))
 					.reduce((l, r) -> r)
 					.flatMap(fileName -> Arrays.stream(fileName.split("\\.")).findFirst())
-					.orElse(e.getValue()),
-				e.getValue()
+					.orElse(e.getValue())
 			))
 			.collect(Collectors.toMap(
 				BundledConfig::getId,

src/main/java/software/xdev/pmd/model/config/bundled/BundledConfigurationLocation.java

@@ -53,6 +53,7 @@ public void validate()
 		// always valid
 	}
 
+	@Nullable
 	@Override
 	protected synchronized RuleSet loadRuleSet()
 	{

src/main/java/software/xdev/pmd/model/config/bundled/UnknownBundledConfigurationLocation.java

@@ -0,0 +1,37 @@
+package software.xdev.pmd.model.config.bundled;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import com.intellij.openapi.project.Project;
+
+import net.sourceforge.pmd.lang.rule.RuleSet;
+
+
+public class UnknownBundledConfigurationLocation extends BundledConfigurationLocation
+{
+	public UnknownBundledConfigurationLocation(
+		final @NotNull String id,
+		final @NotNull Project project)
+	{
+		super(BundledConfig.createUnknownDummy(id), project);
+	}
+	
+	@Override
+	public boolean isRemovable()
+	{
+		return true;
+	}
+	
+	@Override
+	protected synchronized RuleSet loadRuleSet()
+	{
+		return null;
+	}
+	
+	@Override
+	public @Nullable RuleSet getOrRefreshCachedRuleSet()
+	{
+		return null;
+	}
+}