Fix race condition in RunPesterTestsFromFile test

Author: andyleejordan

test/features/RunCode.test.ts

@@ -4,10 +4,11 @@
 import * as assert from "assert";
 import * as fs from "fs";
 import * as path from "path";
-import { suiteSetup } from "mocha";
 import rewire = require("rewire");
 import vscode = require("vscode");
 import utils = require("../utils");
+import { sleep } from "../../src/utils";
+import { IPowerShellExtensionClient } from "../../src/features/ExternalApi";
 
 // Setup function that is not exported.
 const customViews = rewire("../../src/features/RunCode");
@@ -19,8 +20,6 @@ enum LaunchType {
 }
 
 suite("RunCode tests", () => {
-    suiteSetup(utils.ensureExtensionIsActivated);
-
     test("Can create the launch config", () => {
         const commandToRun: string = "Invoke-Build";
         const args: string[] = ["Clean"];
@@ -42,11 +41,33 @@ suite("RunCode tests", () => {
         assert.deepStrictEqual(actual, expected);
     });
 
-    test("Can run Pester tests from file", async () => {
+    test("Can run Pester tests from file", async function() {
+        // PowerShell can take a while and is flaky, so try three times and set
+        // the timeout to thirty seconds each.
+        this.retries(3);
+        this.timeout(30000);
+
         const pesterTests = path.resolve(__dirname, "../../../examples/Tests/SampleModule.Tests.ps1");
         assert(fs.existsSync(pesterTests));
+
+        // Get interface to extension.
+        const extension = await utils.ensureExtensionIsActivated();
+        const client = extension!.exports as IPowerShellExtensionClient;
+        const sessionId = client.registerExternalExtension(utils.extensionId);
+
+        // Force PowerShell extension to finish connecting. This is necessary
+        // because we can't start the PowerShell debugger until the session is
+        // connected, which is different from the extension being activated. We
+        // also need to open the file so the command has it as its argument.
         await vscode.commands.executeCommand("vscode.open", vscode.Uri.file(pesterTests));
+        await client.getPowerShellVersionDetails(sessionId);
+        client.unregisterExternalExtension(sessionId);
+
+        // Now run the Pester tests, check the debugger started, wait a bit for
+        // it to run, and then kill it for safety's sake.
         assert(await vscode.commands.executeCommand("PowerShell.RunPesterTestsFromFile"));
-        // Start up can take some time...so set the timeout to 30 seconds.
-    }).timeout(30000);
+        assert(vscode.debug.activeDebugSession !== undefined);
+        await sleep(5000);
+        await vscode.debug.stopDebugging();
+    });
 });