Show PyPi link in requirements (#23288)

Show PyPi link in requirements, see #14495.

Apart from the test to verify the register of
`RequirementsTxtLinkActivator`, there are no other tests. This is my
first contribution in TypeScript, if you have an example of a test that
could be done, I'm interested :)

---------

Co-authored-by: Karthik Nadig <[email protected]>

Author: LouisGobert

src/client/activation/requirementsTxtLinkActivator.ts

@@ -0,0 +1,26 @@
+import { injectable } from 'inversify';
+import { Hover, languages, TextDocument, Position } from 'vscode';
+import { IExtensionSingleActivationService } from './types';
+
+const PYPI_PROJECT_URL = 'https://pypi.org/project';
+
+export function generatePyPiLink(name: string): string | null {
+    // Regex to allow to find every possible pypi package (base regex from https://peps.python.org/pep-0508/#names)
+    const projectName = name.match(/^([A-Z0-9]|[A-Z0-9][A-Z0-9._-]*)($|=| |;|\[)/i);
+    return projectName ? `${PYPI_PROJECT_URL}/${projectName[1]}/` : null;
+}
+
+@injectable()
+export class RequirementsTxtLinkActivator implements IExtensionSingleActivationService {
+    public readonly supportedWorkspaceTypes = { untrustedWorkspace: true, virtualWorkspace: true };
+
+    // eslint-disable-next-line class-methods-use-this
+    public async activate(): Promise<void> {
+        languages.registerHoverProvider([{ pattern: '**/*requirement*.txt' }, { pattern: '**/requirements/*.txt' }], {
+            provideHover(document: TextDocument, position: Position) {
+                const link = generatePyPiLink(document.lineAt(position.line).text);
+                return link ? new Hover(link) : null;
+            },
+        });
+    }
+}

src/client/activation/serviceRegistry.ts

@@ -15,6 +15,7 @@ import { LoadLanguageServerExtension } from './common/loadLanguageServerExtensio
 import { PartialModeStatusItem } from './partialModeStatus';
 import { ILanguageServerWatcher } from '../languageServer/types';
 import { LanguageServerWatcher } from '../languageServer/watcher';
+import { RequirementsTxtLinkActivator } from './requirementsTxtLinkActivator';
 
 export function registerTypes(serviceManager: IServiceManager): void {
     serviceManager.addSingleton<IExtensionActivationService>(IExtensionActivationService, PartialModeStatusItem);
@@ -34,4 +35,9 @@ export function registerTypes(serviceManager: IServiceManager): void {
 
     serviceManager.addSingleton<ILanguageServerWatcher>(ILanguageServerWatcher, LanguageServerWatcher);
     serviceManager.addBinding(ILanguageServerWatcher, IExtensionActivationService);
+
+    serviceManager.addSingleton<IExtensionSingleActivationService>(
+        IExtensionSingleActivationService,
+        RequirementsTxtLinkActivator,
+    );
 }

src/test/activation/requirementsTxtLinkActivator.unit.test.ts

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+'use strict';
+
+import { expect } from 'chai';
+import { generatePyPiLink } from '../../client/activation/requirementsTxtLinkActivator';
+
+suite('Link to PyPi in requiements test', () => {
+    [
+        ['pytest', 'pytest'],
+        ['pytest-cov', 'pytest-cov'],
+        ['pytest_cov', 'pytest_cov'],
+        ['pytest_cov[an_extra]', 'pytest_cov'],
+        ['pytest == 0.6.1', 'pytest'],
+        ['pytest== 0.6.1', 'pytest'],
+        ['requests [security] >= 2.8.1, == 2.8.* ; python_version < "2.7"', 'requests'],
+        ['# a comment', null],
+        ['', null],
+    ].forEach(([input, expected]) => {
+        test(`PyPI link case: "${input}"`, () => {
+            expect(generatePyPiLink(input!)).equal(expected ? `https://pypi.org/project/${expected}/` : null);
+        });
+    });
+});

src/test/activation/serviceRegistry.unit.test.ts

@@ -14,6 +14,7 @@ import {
 import { ServiceManager } from '../../client/ioc/serviceManager';
 import { IServiceManager } from '../../client/ioc/types';
 import { LoadLanguageServerExtension } from '../../client/activation/common/loadLanguageServerExtension';
+import { RequirementsTxtLinkActivator } from '../../client/activation/requirementsTxtLinkActivator';
 
 suite('Unit Tests - Language Server Activation Service Registry', () => {
     let serviceManager: IServiceManager;
@@ -46,5 +47,11 @@ suite('Unit Tests - Language Server Activation Service Registry', () => {
                 LoadLanguageServerExtension,
             ),
         ).once();
+        verify(
+            serviceManager.addSingleton<IExtensionSingleActivationService>(
+                IExtensionSingleActivationService,
+                RequirementsTxtLinkActivator,
+            ),
+        ).once();
     });
 });