Fix: filter flag+value pairs when removing \ args

When filtering out args containing \ (for calls without a
test name), also remove the preceding flag argument (e.g., --output-log)
to avoid leaving dangling flags that cause ctest to fail.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Omotola

src/ctest.ts

@@ -462,9 +462,25 @@ export class CTestDriver implements vscode.Disposable {
 
         // When testName is not provided, filter out args containing ${testName} to avoid
         // passing literal "${testName}" to ctest (e.g., during test discovery or batch runs).
+        // Also removes the preceding flag arg (e.g., "--output-log") to avoid dangling flags.
         const testNamePlaceholder = '${testName}';
-        const filterTestNameArgs = (args: string[]): string[] =>
-            testName !== undefined ? args : args.filter(arg => !arg.includes(testNamePlaceholder));
+        const filterTestNameArgs = (args: string[]): string[] => {
+            if (testName !== undefined) {
+                return args;
+            }
+            const filtered: string[] = [];
+            for (let i = 0; i < args.length; i++) {
+                if (args[i].includes(testNamePlaceholder)) {
+                    // Also remove preceding flag arg if it starts with '-'
+                    if (filtered.length > 0 && filtered[filtered.length - 1].startsWith('-')) {
+                        filtered.pop();
+                    }
+                } else {
+                    filtered.push(args[i]);
+                }
+            }
+            return filtered;
+        };
 
         const initialArgs = await Promise.all(filterTestNameArgs(this.ws.config.ctestDefaultArgs).map(async (value) => expandString(value, opts)));
         const additionalArgs = await Promise.all(filterTestNameArgs(this.ws.config.ctestArgs).map(async (value) => expandString(value, opts)));