Fix "Run Tests Multiple Times" on Linux (#1824)

* Fix "Run Tests Multiple Times" on Linux

When we process the `...args` passed to the 'run multiple' commands
we're only checking if the argument is an object before deeming it a
TestItem.

On linux VS Code is passing an event object like `{ preserveFocus: true }`,
which is being treated as a TestItem and causing the command to error
out.

Author: plemarquand

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 - Don't start debugging XCTest cases if the swift-testing debug session was stopped ([#1797](https://github.com/swiftlang/vscode-swift/pull/1797))
 - Improve error handling when the swift path is misconfigured ([#1801](https://github.com/swiftlang/vscode-swift/pull/1801))
+- Fix an error when performing "Run/Debug Tests Multiple Times" on Linux ([#1824](https://github.com/swiftlang/vscode-swift/pull/1824))
 
 ## 2.11.20250806 - 2025-08-06
 

src/commands/testMultipleTimes.ts

@@ -51,9 +51,10 @@ export async function runTestMultipleTimes(
     }
     const token = new vscode.CancellationTokenSource();
     const testExplorer = currentFolder.testExplorer;
+    const request = new vscode.TestRunRequest(tests);
     const runner = new TestRunner(
         kind,
-        new vscode.TestRunRequest(tests),
+        request,
         currentFolder,
         testExplorer.controller,
         token.token
@@ -110,9 +111,7 @@ export async function runTestMultipleTimes(
  * also accept a final count parameter. We have to find the count parameter ourselves since JavaScript
  * only supports varargs at the end of an argument list.
  */
-export function extractTestItemsAndCount(
-    ...args: (vscode.TestItem | number | undefined | null)[]
-): {
+export function extractTestItemsAndCount(...args: unknown[]): {
     testItems: vscode.TestItem[];
     count?: number;
 } {
@@ -126,9 +125,12 @@ export function extractTestItemsAndCount(
             } else if (typeof arg === "number" && index === args.length - 1) {
                 result.count = arg ?? undefined;
                 return result;
-            } else if (typeof arg === "object") {
+            } else if (isVSCodeTestItem(arg)) {
                 result.testItems.push(arg);
                 return result;
+            } else if (typeof arg === "object") {
+                // Object but not a TestItem, just skip it
+                return result;
             } else {
                 throw new Error(`Unexpected argument ${arg} at index ${index}`);
             }
@@ -137,3 +139,15 @@ export function extractTestItemsAndCount(
     );
     return result;
 }
+
+/**
+ * Checks if an object is a vscode.TestItem via duck typing.
+ */
+function isVSCodeTestItem(obj: unknown): obj is vscode.TestItem {
+    return (
+        typeof obj === "object" &&
+        obj !== null &&
+        Object.prototype.hasOwnProperty.call(obj, "id") &&
+        Object.prototype.hasOwnProperty.call(obj, "uri")
+    );
+}

test/integration-tests/testexplorer/TestExplorerIntegration.test.ts

@@ -597,6 +597,7 @@ tag("large").suite("Test Explorer Suite", function () {
                     await vscode.commands.executeCommand(
                         Commands.RUN_TESTS_MULTIPLE_TIMES,
                         testItems[0],
+                        { preserveFocus: true }, // a trailing argument included on Linux
                         numIterations
                     );
 

test/unit-tests/commands/runTestMultipleTimes.test.ts

@@ -19,7 +19,7 @@ import { extractTestItemsAndCount } from "@src/commands/testMultipleTimes";
 suite("Run Tests Multiple Times", () => {
     suite("extractTestItemsAndCount()", () => {
         function createDummyTestItem(label: string): vscode.TestItem {
-            return { label } as vscode.TestItem;
+            return { id: label, uri: vscode.Uri.file(`/dummy/path/${label}`) } as vscode.TestItem;
         }
 
         test("handles empty arguments", () => {