treat pnpm and yarn workspace equally

plugins/org.eclipse.n4js/src/org/eclipse/n4js/packagejson/PackageJsonHelper.java

@@ -583,9 +583,9 @@ private void applyN4JSDefaults(ProjectDescriptionBuilder target, String defaultP
 	private void setSourceContainer(ProjectDescriptionBuilder target, String path, boolean replace) {
 		// if no source containers are defined (no matter what type),
 		// then add a default source container of type "source" with path "."
-		// EXCEPT target represents a yarn workspace root
+		// EXCEPT target represents a workspace root
 
-		if (!target.isYarnWorkspaceRoot()) {
+		if (!target.isWorkspaceRoot()) {
 			List<SourceContainerDescription> sourceContainers = target.getSourceContainers();
 			SourceContainerDescription sourceContainerOfTypeSource = null;
 			for (SourceContainerDescription sourceContainer : sourceContainers) {

plugins/org.eclipse.n4js/src/org/eclipse/n4js/packagejson/projectDescription/ProjectDescription.java

@@ -382,6 +382,13 @@ public boolean hasN4JSNature() {
 		return n4jsNature;
 	}
 
+	/**
+	 * True iff the project represented by this project description is the root of either a yarn or pnpm workspace.
+	 */
+	public boolean isWorkspaceRoot() {
+		return isYarnWorkspaceRoot() || isPnpmWorkspaceRoot();
+	}
+
 	/**
 	 * Tells whether the project represented by this project description is the root of a yarn workspace. This flag will
 	 * be {@code true} iff the package.json contains yarn's top-level property "workspaces", no matter the value (i.e.
@@ -485,6 +492,7 @@ protected int computeHashCode() {
 				esm,
 				moduleProperty,
 				n4jsNature,
+				pnpmWorkspaceRoot,
 				yarnWorkspaceRoot,
 				isGeneratorEnabledSourceMaps,
 				isGeneratorEnabledDts,

plugins/org.eclipse.n4js/src/org/eclipse/n4js/packagejson/projectDescription/ProjectDescriptionBuilder.java

@@ -379,6 +379,10 @@ public ProjectDescriptionBuilder setN4JSNature(boolean n4jsNature) {
 		return this;
 	}
 
+	public boolean isWorkspaceRoot() {
+		return isYarnWorkspaceRoot() || isPnpmWorkspaceRoot();
+	}
+
 	public boolean isPnpmWorkspaceRoot() {
 		return pnpmWorkspaceRoot;
 	}

plugins/org.eclipse.n4js/src/org/eclipse/n4js/utils/NodeModulesDiscoveryHelper.java

@@ -276,7 +276,7 @@ private List<String> getWorkspacesOfYarnWorkspaceProject(File yarnProjectFolder,
 							.loadProjectDescriptionAtLocation(location, null);
 					return pd;
 				});
-		final List<String> workspaces = (prjDescr != null && prjDescr.isYarnWorkspaceRoot())
+		final List<String> workspaces = (prjDescr != null && prjDescr.isWorkspaceRoot())
 				? prjDescr.getWorkspaces()
 				: null;
 

plugins/org.eclipse.n4js/src/org/eclipse/n4js/workspace/N4JSProjectConfig.java

@@ -187,7 +187,7 @@ public N4JSPackageName getN4JSPackageName() {
 
 	/** Tells whether this project is a yarn workspace project. */
 	public boolean isWorkspaceProject() {
-		return projectDescription.isYarnWorkspaceRoot()
+		return projectDescription.isWorkspaceRoot()
 				&& projectDescription.getWorkspaces() != null
 				&& !projectDescription.getWorkspaces().isEmpty();
 	}