Add CodeLens support for running and debugging Pester tests

This change adds a new PowerShell.RunPesterTests command which can be
invoked by CodeLenses which appear on Describe blocks in Pester test
files.  This allows the user to run or debug all of the tests in a
particular Describe block.

Author: daviwil

src/features/PesterTests.ts

@@ -0,0 +1,66 @@
+/*---------------------------------------------------------
+ * Copyright (C) Microsoft Corporation. All rights reserved.
+ *--------------------------------------------------------*/
+
+import vscode = require('vscode');
+import utils = require('../utils');
+import Window = vscode.window;
+import ChildProcess = require('child_process');
+import { SessionManager } from '../session';
+import { IFeature, LanguageClient } from '../feature';
+
+export class PesterTestsFeature implements IFeature {
+
+    private command: vscode.Disposable;
+    private languageClient: LanguageClient;
+
+    constructor(private sessionManager: SessionManager) {
+        this.command = vscode.commands.registerCommand(
+            'PowerShell.RunPesterTests',
+            (uriString, runInDebugger, describeBlockName?) => {
+                this.launchTests(uriString, runInDebugger, describeBlockName);
+            });
+    }
+
+    public setLanguageClient(languageClient: LanguageClient) {
+        this.languageClient = languageClient;
+    }
+
+    public dispose() {
+        this.command.dispose();
+    }
+
+    private launchTests(uriString, runInDebugger, describeBlockName?) {
+        var uri = vscode.Uri.parse(uriString);
+        let currentDocument = vscode.window.activeTextEditor.document;
+
+        let launchConfig = {
+            request: "launch",
+            type: "PowerShell",
+            script: "Invoke-Pester",
+            args: [
+                `-Script "${uri.fsPath}"`,
+                describeBlockName
+                    ? `-TestName "${describeBlockName}"`
+                    : ""
+            ],
+            internalConsoleOptions: "neverOpen",
+            noDebug: !runInDebugger,
+            cwd:
+                currentDocument.isUntitled
+                    ? vscode.workspace.rootPath
+                    : currentDocument.fileName
+        }
+
+        // Create or show the interactive console
+        // TODO #367: Check if "newSession" mode is configured
+        vscode.commands.executeCommand('PowerShell.ShowSessionConsole', true);
+
+        // Write out temporary debug session file
+        utils.writeSessionFile(
+            utils.getDebugSessionFilePath(),
+            this.sessionManager.getSessionDetails());
+
+        vscode.commands.executeCommand('vscode.startDebug', launchConfig);
+    }
+}

src/main.ts

@@ -19,6 +19,7 @@ import { ExpandAliasFeature } from './features/ExpandAlias';
 import { ShowHelpFeature } from './features/ShowOnlineHelp';
 import { CodeActionsFeature } from './features/CodeActions';
 import { RemoteFilesFeature } from './features/RemoteFiles';
+import { PesterTestsFeature } from './features/PesterTests';
 import { DebugSessionFeature } from './features/DebugSession';
 import { PickPSHostProcessFeature } from './features/DebugSession';
 import { SpecifyScriptArgsFeature } from './features/DebugSession';
@@ -110,6 +111,7 @@ export function activate(context: vscode.ExtensionContext): void {
         new ExpandAliasFeature(),
         new ShowHelpFeature(),
         new FindModuleFeature(),
+        new PesterTestsFeature(sessionManager),
         new ExtensionCommandsFeature(),
         new SelectPSSARulesFeature(),
         new CodeActionsFeature(),