Update list of available solutions on demand (#212)

* Update list of available solutions on demand

* Update src/solutions/active-solution-tracker.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Roll back copilot suggestion

* lint errors

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: edriouk

src/solutions/active-solution-tracker.test.ts

@@ -117,6 +117,26 @@ describe('ActiveSolutionTracker', () => {
         expect(workspaceFoldersProvider.findFiles).toHaveBeenCalledWith(ActiveSolutionTrackerImpl.GLOB_PATTERN, testGlobPattern);
     });
 
+    it('sets the given solution as active before the initial refresh completes', async () => {
+        let resolveExtensionActivation: () => void;
+        const extensionActivation = new Promise<void>(resolve => {
+            resolveExtensionActivation = resolve;
+        });
+
+        context.extension.activate.mockReturnValue(extensionActivation);
+
+        const activeSolutionChanged = waitForEvent(activeSolutionTracker.onDidChangeActiveSolution);
+
+        activeSolutionTracker.activate(context as unknown as vscode.ExtensionContext);
+        await commandsProvider.mockRunRegistered(COMMAND_ACTIVATE_SOLUTION, SOLUTION_URI_FOO.fsPath);
+        await activeSolutionChanged;
+
+        expect(activeSolutionTracker.activeSolution).toEqual(SOLUTION_URI_FOO.fsPath);
+        expect(changeActiveListener).toHaveBeenCalledTimes(1);
+
+        resolveExtensionActivation!();
+    });
+
     it('updates when the configured glob pattern changes', async () => {
         activeSolutionTracker.activate(context as unknown as vscode.ExtensionContext);
         await waitForEvent(activeSolutionTracker.onDidChangeSolutions, undefined, 200);;

src/solutions/active-solution-tracker.ts

@@ -266,6 +266,13 @@ export class ActiveSolutionTrackerImpl implements ActiveSolutionTracker {
             return;
         }
         const inputFsPath = await this.getCsolutionFile(inputSolutionPath);
+
+        // A request can arrive before the debounced activation path triggers refresh.
+        // Update the cached solutions list immediately
+        // to prevent activation of default solution
+        if (this._solutions.length === 0) {
+            this._solutions = await this.getSolutionPaths();
+        }
         return this.solutions.includes(inputFsPath) ? inputFsPath : undefined;
     }