added new unit tests to validate document manager cache

Author: Deep Furiya

tst/unit/document/DocumentManager.test.ts

@@ -63,4 +63,94 @@ describe('DocumentManager', () => {
             expect(documentManager.getLine('file:///nonexistent.yaml', 0)).toBeUndefined();
         });
     });
+
+    describe('document cache updates', () => {
+        it('should cache document on first access', () => {
+            const uri = 'file:///test.yaml';
+            const content = 'Resources:\n  Bucket:\n    Type: AWS::S3::Bucket';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, content);
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc1 = documentManager.get(uri);
+            const doc2 = documentManager.get(uri);
+
+            expect(doc1).toBe(doc2);
+        });
+
+        it('should return updated content when TextDocument is mutated', () => {
+            const uri = 'file:///test.yaml';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, 'old content');
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc = documentManager.get(uri);
+            expect(doc?.contents()).toBe('old content');
+
+            TextDocument.update(textDocument, [{ text: 'new content' }], 2);
+
+            expect(doc?.contents()).toBe('new content');
+        });
+
+        it('should return updated version when TextDocument is mutated', () => {
+            const uri = 'file:///test.yaml';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, 'content');
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc = documentManager.get(uri);
+            expect(doc?.version).toBe(1);
+
+            TextDocument.update(textDocument, [{ text: 'updated' }], 2);
+
+            expect(doc?.version).toBe(2);
+        });
+
+        it('should return updated lineCount when TextDocument is mutated', () => {
+            const uri = 'file:///test.yaml';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, 'line1');
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc = documentManager.get(uri);
+            expect(doc?.lineCount).toBe(1);
+
+            TextDocument.update(textDocument, [{ text: 'line1\nline2\nline3' }], 2);
+
+            expect(doc?.lineCount).toBe(3);
+        });
+
+        it('should remove document from cache', () => {
+            const uri = 'file:///test.yaml';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, 'content');
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc1 = documentManager.get(uri);
+            expect(doc1).toBeDefined();
+
+            documentManager.removeDocument(uri);
+
+            const doc2 = documentManager.get(uri);
+            expect(doc2).not.toBe(doc1);
+        });
+
+        it('should recreate document after cache invalidation', () => {
+            const uri = 'file:///test.yaml';
+            const textDocument = TextDocument.create(uri, 'yaml', 1, 'Resources: {}');
+
+            mockDocuments.get.returns(textDocument);
+
+            const doc1 = documentManager.get(uri);
+            expect(doc1?.cfnFileType).toBe(CloudFormationFileType.Template);
+
+            documentManager.removeDocument(uri);
+
+            TextDocument.update(textDocument, [{ text: 'name: app' }], 2);
+
+            const doc2 = documentManager.get(uri);
+            expect(doc2).not.toBe(doc1);
+            expect(doc2?.cfnFileType).toBe(CloudFormationFileType.Other);
+        });
+    });
 });