test: Add test for DeepnoteRequirementsHelper (#178)

* test: Add test for DeepnoteRequirementsHelper

Signed-off-by: Tomas Kislan <tomas@kislan.sk>

* Fix test

Signed-off-by: Tomas Kislan <tomas@kislan.sk>

* fix: Add ENOENT code in mocked test error

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Signed-off-by: Tomas Kislan <tomas@kislan.sk>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: tkislan

src/notebooks/deepnote/deepnoteRequirementsHelper.node.unit.test.ts

@@ -0,0 +1,95 @@
+import { assert } from 'chai';
+import * as sinon from 'sinon';
+import { instance, mock, when } from 'ts-mockito';
+import { CancellationToken, Uri, WorkspaceFolder } from 'vscode';
+import * as fs from 'fs';
+
+import { DeepnoteRequirementsHelper } from './deepnoteRequirementsHelper.node';
+import type { DeepnoteProject } from '../../platform/deepnote/deepnoteTypes';
+import { ILogger } from '../../platform/logging/types';
+import { IPersistentStateFactory } from '../../platform/common/types';
+import { mockedVSCodeNamespaces, resetVSCodeMocks } from '../../test/vscode-mock';
+
+suite('DeepnoteRequirementsHelper', () => {
+    let helper: DeepnoteRequirementsHelper;
+    let mockLogger: ILogger;
+    let mockPersistentStateFactory: IPersistentStateFactory;
+    let mockCancellationToken: CancellationToken;
+    let sandbox: sinon.SinonSandbox;
+
+    setup(() => {
+        resetVSCodeMocks();
+        sandbox = sinon.createSandbox();
+
+        // Create mocks
+        mockLogger = mock<ILogger>();
+        mockPersistentStateFactory = mock<IPersistentStateFactory>();
+        mockCancellationToken = mock<CancellationToken>();
+
+        // Setup default behavior for cancellation token
+        when(mockCancellationToken.isCancellationRequested).thenReturn(false);
+
+        // Create the helper with mocked dependencies
+        helper = new DeepnoteRequirementsHelper(instance(mockLogger), instance(mockPersistentStateFactory));
+    });
+
+    teardown(() => {
+        sandbox.restore();
+        resetVSCodeMocks();
+    });
+
+    test('should create requirements.txt file with valid requirements', async () => {
+        // Arrange
+        const workspaceUri = Uri.file('/test/workspace');
+        const mockWorkspaceFolder: WorkspaceFolder = {
+            uri: workspaceUri,
+            name: 'test-workspace',
+            index: 0
+        };
+
+        when(mockedVSCodeNamespaces.workspace.workspaceFolders).thenReturn([mockWorkspaceFolder]);
+
+        const project: DeepnoteProject = {
+            metadata: {
+                createdAt: '2024-01-01T00:00:00Z'
+            },
+            version: '1',
+            project: {
+                id: 'test-project-id',
+                name: 'Test Project',
+                notebooks: [],
+                settings: {
+                    requirements: ['numpy>=1.20.0', 'pandas==1.3.0', 'matplotlib']
+                }
+            }
+        };
+
+        // Mock fs.promises to check file doesn't exist
+        const fsAccessStub = sandbox.stub(fs.promises, 'access');
+        const notFoundError = Object.assign(new Error('File not found'), { code: 'ENOENT' });
+        fsAccessStub.rejects(notFoundError);
+
+        // Mock fs.promises.writeFile to capture what's written
+        let writtenContent = '';
+        let writtenPath = '';
+        const fsWriteFileStub = sandbox.stub(fs.promises, 'writeFile');
+        fsWriteFileStub.callsFake(async (path, content) => {
+            writtenPath = path.toString();
+            writtenContent = content.toString();
+        });
+
+        // Act
+        await helper.createRequirementsFile(project, instance(mockCancellationToken));
+
+        // Assert
+        assert.isTrue(fsWriteFileStub.calledOnce, 'writeFile should be called once');
+        assert.include(writtenPath, 'requirements.txt', 'Should write to requirements.txt');
+        assert.include(writtenContent, 'numpy>=1.20.0', 'Should include numpy requirement');
+        assert.include(writtenContent, 'pandas==1.3.0', 'Should include pandas requirement');
+        assert.include(writtenContent, 'matplotlib', 'Should include matplotlib requirement');
+
+        // Verify content format (should have LF line endings)
+        const expectedContent = 'numpy>=1.20.0\npandas==1.3.0\nmatplotlib\n';
+        assert.strictEqual(writtenContent, expectedContent, 'Content should match expected format');
+    });
+});