Add test for file change additions/deletions

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/test/common/fileChange.test.ts

@@ -0,0 +1,77 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { default as assert } from 'assert';
+import { InMemFileChange, SlimFileChange, GitChangeType } from '../../common/file';
+
+describe('File Change with additions/deletions', () => {
+	it('InMemFileChange should store additions and deletions', () => {
+		const fileChange = new InMemFileChange(
+			'base-commit-sha',
+			GitChangeType.MODIFY,
+			'test-file.ts',
+			undefined,
+			'@@ -1,1 +1,1 @@\n-old\n+new',
+			undefined,
+			'https://blob-url',
+			10,
+			5
+		);
+
+		assert.strictEqual(fileChange.additions, 10);
+		assert.strictEqual(fileChange.deletions, 5);
+		assert.strictEqual(fileChange.fileName, 'test-file.ts');
+		assert.strictEqual(fileChange.status, GitChangeType.MODIFY);
+	});
+
+	it('InMemFileChange should handle undefined additions/deletions', () => {
+		const fileChange = new InMemFileChange(
+			'base-commit-sha',
+			GitChangeType.ADD,
+			'new-file.ts',
+			undefined,
+			'',
+			undefined,
+			'https://blob-url',
+			undefined,
+			undefined
+		);
+
+		assert.strictEqual(fileChange.additions, undefined);
+		assert.strictEqual(fileChange.deletions, undefined);
+	});
+
+	it('SlimFileChange should store additions and deletions', () => {
+		const fileChange = new SlimFileChange(
+			'base-commit-sha',
+			'https://blob-url',
+			GitChangeType.MODIFY,
+			'slim-file.ts',
+			undefined,
+			20,
+			15
+		);
+
+		assert.strictEqual(fileChange.additions, 20);
+		assert.strictEqual(fileChange.deletions, 15);
+		assert.strictEqual(fileChange.fileName, 'slim-file.ts');
+		assert.strictEqual(fileChange.status, GitChangeType.MODIFY);
+	});
+
+	it('SlimFileChange should handle undefined additions/deletions', () => {
+		const fileChange = new SlimFileChange(
+			'base-commit-sha',
+			'https://blob-url',
+			GitChangeType.DELETE,
+			'deleted-file.ts',
+			undefined,
+			undefined,
+			undefined
+		);
+
+		assert.strictEqual(fileChange.additions, undefined);
+		assert.strictEqual(fileChange.deletions, undefined);
+	});
+});