fix: multiple document-builder listeners (#1738)

Signed-off-by: Christian Dietrich <[email protected]>

Author: cdietrich

packages/langium/src/workspace/document-builder.ts

@@ -452,7 +452,8 @@ export class DefaultDocumentBuilder implements DocumentBuilder {
 
     protected async notifyDocumentPhase(document: LangiumDocument, state: DocumentState, cancelToken: CancellationToken): Promise<void> {
         const listeners = this.documentPhaseListeners.get(state);
-        for (const listener of listeners) {
+        const listenersCopy = listeners.slice();
+        for (const listener of listenersCopy) {
             try {
                 await listener(document, cancelToken);
             } catch (err) {
@@ -471,7 +472,8 @@ export class DefaultDocumentBuilder implements DocumentBuilder {
             return;
         }
         const listeners = this.buildPhaseListeners.get(state);
-        for (const listener of listeners) {
+        const listenersCopy = listeners.slice();
+        for (const listener of listenersCopy) {
             await interruptAndCheck(cancelToken);
             await listener(documents, cancelToken);
         }

packages/langium/test/workspace/document-builder.test.ts

@@ -283,6 +283,60 @@ describe('DefaultDocumentBuilder', () => {
         ]);
     });
 
+    test('can handle multiple listeners (buildPhase)', async () => {
+        const services = await createServices();
+        const workspace = services.shared.workspace;
+        const documentFactory = workspace.LangiumDocumentFactory;
+        const documents = workspace.LangiumDocuments;
+        const uri = URI.parse('file:///test1.txt');
+        const document1 = documentFactory.fromString(`
+            foo 1 A
+            foo 11 B
+            bar A
+            bar B
+        `, uri);
+        documents.addDocument(document1);
+
+        const builder = workspace.DocumentBuilder;
+        const p1 = builder.waitUntil(DocumentState.IndexedReferences, uri).then(() => {
+        });
+        const p2 = builder.waitUntil(DocumentState.IndexedReferences, uri).then(() => {
+        });
+        await builder.build([document1], {});
+        await Promise.all([p1, p2]);
+        expect(document1.state).toBe(DocumentState.IndexedReferences);
+    });
+
+    test('can handle multiple listeners (documentPhase)', async () => {
+        const services = await createServices();
+        const workspace = services.shared.workspace;
+        const documentFactory = workspace.LangiumDocumentFactory;
+        const documents = workspace.LangiumDocuments;
+        const uri = URI.parse('file:///test1.txt');
+        const document1 = documentFactory.fromString(`
+            foo 1 A
+            foo 11 B
+            bar A
+            bar B
+        `, uri);
+        documents.addDocument(document1);
+
+        const builder = workspace.DocumentBuilder;
+        let p1called = false;
+        const p1 = builder.onDocumentPhase(DocumentState.IndexedReferences, (_d) => {
+            p1called = true;
+            p1.dispose();
+        });
+        let p2called = false;
+        const p2 = builder.onDocumentPhase(DocumentState.IndexedReferences, (_d) => {
+            p2called = true;
+            p2.dispose();
+        });
+        await builder.build([document1], {});
+        expect(p1called).toBe(true);
+        expect(p2called).toBe(true);
+    });
+
     test('waits until a specific workspace stage has been reached', async () => {
         const services = await createServices();
         const documentFactory = services.shared.workspace.LangiumDocumentFactory;