Add comprehensive tests for getProjectInstallable

- Test finding dev-requirements.txt at workspace root
- Test deduplication of files found by multiple patterns
- Test finding files in subdirectories and requirements/ folders
- Test filtering files by project directories
- All 181 unit tests passing (5 new tests added)

Co-authored-by: eleanorjboyd <26030610+eleanorjboyd@users.noreply.github.com>

Author: Copilot

src/test/managers/builtin/pipUtils.unit.test.ts

@@ -0,0 +1,186 @@
+import assert from 'assert';
+import * as sinon from 'sinon';
+import { Uri } from 'vscode';
+import { getProjectInstallable } from '../../../managers/builtin/pipUtils';
+import * as wapi from '../../../common/workspace.apis';
+import * as winapi from '../../../common/window.apis';
+
+suite('Pip Utils - getProjectInstallable', () => {
+    let findFilesStub: sinon.SinonStub;
+    let withProgressStub: sinon.SinonStub;
+    let mockApi: any;
+
+    setup(() => {
+        findFilesStub = sinon.stub(wapi, 'findFiles');
+        // Stub withProgress to immediately execute the callback
+        withProgressStub = sinon.stub(winapi, 'withProgress');
+        withProgressStub.callsFake(async (_options: any, callback: any) => {
+            return await callback(undefined, { isCancellationRequested: false });
+        });
+        
+        mockApi = {
+            getPythonProject: (uri: Uri) => {
+                // Return a project for any URI in /workspace
+                if (uri.fsPath.startsWith('/workspace')) {
+                    return { uri: Uri.file('/workspace') };
+                }
+                return undefined;
+            },
+        };
+    });
+
+    teardown(() => {
+        sinon.restore();
+    });
+
+    test('should find dev-requirements.txt at workspace root', async () => {
+        // Arrange: Mock findFiles to return both requirements.txt and dev-requirements.txt
+        findFilesStub.callsFake((pattern: string) => {
+            if (pattern === '**/*requirements*.txt') {
+                // This pattern might not match root-level files in VS Code
+                return Promise.resolve([]);
+            } else if (pattern === '*requirements*.txt') {
+                // This pattern should match root-level files
+                return Promise.resolve([
+                    Uri.file('/workspace/requirements.txt'),
+                    Uri.file('/workspace/dev-requirements.txt'),
+                    Uri.file('/workspace/test-requirements.txt'),
+                ]);
+            } else if (pattern === '**/requirements/*.txt') {
+                return Promise.resolve([]);
+            } else if (pattern === '**/pyproject.toml') {
+                return Promise.resolve([]);
+            }
+            return Promise.resolve([]);
+        });
+
+        // Act: Call getProjectInstallable
+        const projects = [{ name: 'workspace', uri: Uri.file('/workspace') }];
+        const result = await getProjectInstallable(mockApi, projects);
+
+        // Assert: Should find all three requirements files
+        assert.strictEqual(result.length, 3, 'Should find three requirements files');
+        
+        const names = result.map((r) => r.name).sort();
+        assert.deepStrictEqual(
+            names,
+            ['dev-requirements.txt', 'requirements.txt', 'test-requirements.txt'],
+            'Should find requirements.txt, dev-requirements.txt, and test-requirements.txt',
+        );
+
+        // Verify each file has correct properties
+        result.forEach((item) => {
+            assert.strictEqual(item.group, 'Requirements', 'Should be in Requirements group');
+            assert.ok(item.args, 'Should have args');
+            assert.strictEqual(item.args?.length, 2, 'Should have 2 args');
+            assert.strictEqual(item.args?.[0], '-r', 'First arg should be -r');
+            assert.ok(item.uri, 'Should have a URI');
+        });
+    });
+
+    test('should deduplicate files found by multiple patterns', async () => {
+        // Arrange: Mock both patterns to return the same file
+        findFilesStub.callsFake((pattern: string) => {
+            if (pattern === '**/*requirements*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/dev-requirements.txt'),
+                ]);
+            } else if (pattern === '*requirements*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/dev-requirements.txt'),
+                    Uri.file('/workspace/requirements.txt'),
+                ]);
+            } else if (pattern === '**/requirements/*.txt') {
+                return Promise.resolve([]);
+            } else if (pattern === '**/pyproject.toml') {
+                return Promise.resolve([]);
+            }
+            return Promise.resolve([]);
+        });
+
+        // Act: Call getProjectInstallable
+        const projects = [{ name: 'workspace', uri: Uri.file('/workspace') }];
+        const result = await getProjectInstallable(mockApi, projects);
+
+        // Assert: Should deduplicate and only have 2 unique files
+        assert.strictEqual(result.length, 2, 'Should deduplicate and have 2 unique files');
+        
+        const names = result.map((r) => r.name).sort();
+        assert.deepStrictEqual(
+            names,
+            ['dev-requirements.txt', 'requirements.txt'],
+            'Should have deduplicated results',
+        );
+    });
+
+    test('should find requirements files in subdirectories', async () => {
+        // Arrange: Mock findFiles to return files in subdirectories
+        findFilesStub.callsFake((pattern: string) => {
+            if (pattern === '**/*requirements*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/subdir/dev-requirements.txt'),
+                ]);
+            } else if (pattern === '*requirements*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/requirements.txt'),
+                ]);
+            } else if (pattern === '**/requirements/*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/requirements/test.txt'),
+                ]);
+            } else if (pattern === '**/pyproject.toml') {
+                return Promise.resolve([]);
+            }
+            return Promise.resolve([]);
+        });
+
+        // Act: Call getProjectInstallable
+        const projects = [{ name: 'workspace', uri: Uri.file('/workspace') }];
+        const result = await getProjectInstallable(mockApi, projects);
+
+        // Assert: Should find all files
+        assert.strictEqual(result.length, 3, 'Should find three files');
+        
+        const names = result.map((r) => r.name).sort();
+        assert.deepStrictEqual(
+            names,
+            ['dev-requirements.txt', 'requirements.txt', 'test.txt'],
+            'Should find files at different levels',
+        );
+    });
+
+    test('should return empty array when no projects provided', async () => {
+        // Act: Call with no projects
+        const result = await getProjectInstallable(mockApi, undefined);
+
+        // Assert: Should return empty array
+        assert.strictEqual(result.length, 0, 'Should return empty array');
+        assert.ok(!findFilesStub.called, 'Should not call findFiles when no projects');
+    });
+
+    test('should filter out files not in project directories', async () => {
+        // Arrange: Mock findFiles to return files from multiple directories
+        findFilesStub.callsFake((pattern: string) => {
+            if (pattern === '*requirements*.txt') {
+                return Promise.resolve([
+                    Uri.file('/workspace/requirements.txt'),
+                    Uri.file('/other-dir/requirements.txt'), // Should be filtered out
+                ]);
+            } else {
+                return Promise.resolve([]);
+            }
+        });
+
+        // Act: Call with only /workspace project
+        const projects = [{ name: 'workspace', uri: Uri.file('/workspace') }];
+        const result = await getProjectInstallable(mockApi, projects);
+
+        // Assert: Should only include files from /workspace
+        assert.strictEqual(result.length, 1, 'Should only include files from project directory');
+        const firstResult = result[0];
+        assert.ok(firstResult, 'Should have at least one result');
+        assert.strictEqual(firstResult.name, 'requirements.txt');
+        assert.ok(firstResult.uri, 'Should have a URI');
+        assert.ok(firstResult.uri.fsPath.startsWith('/workspace'), 'Should be in workspace directory');
+    });
+});