fix: TestRunWriter.appendLine should append trailing newline

Author: recca0120

packages/extension/src/Observers/Writers/TestRunWriter.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it, vi } from 'vitest';
+import type { TestRun } from 'vscode';
+import { TestRunWriter } from './TestRunWriter';
+
+describe('TestRunWriter', () => {
+    it('append delegates to testRun.appendOutput', () => {
+        const spy = vi.fn();
+        const testRun = { appendOutput: spy } as unknown as TestRun;
+        const writer = new TestRunWriter(testRun);
+
+        writer.append('hello');
+
+        expect(spy).toHaveBeenCalledWith('hello');
+    });
+
+    it('appendLine delegates to testRun.appendOutput with trailing newline', () => {
+        const spy = vi.fn();
+        const testRun = { appendOutput: spy } as unknown as TestRun;
+        const writer = new TestRunWriter(testRun);
+
+        writer.appendLine('hello');
+
+        expect(spy).toHaveBeenCalledWith('hello\n');
+    });
+});

packages/extension/src/Observers/Writers/TestRunWriter.ts

@@ -9,6 +9,6 @@ export class TestRunWriter implements OutputWriter {
     }
 
     appendLine(text: string): void {
-        this.testRun.appendOutput(text);
+        this.testRun.appendOutput(text + '\n');
     }
 }