Make F5 auto-install the required debugger extension on first run (#32)

README.md

@@ -133,10 +133,12 @@ The extension provides a **custom `winapp` debug type** that launches your app w
 
 | `debuggerType` | Language | Required Extension |
 |----------------|----------|--------------------|
-| `coreclr` (default) | C# / .NET | [C# Dev Kit](https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.csharp) |
+| `coreclr` | C# / .NET | [C#](https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.csharp) |
 | `cppvsdbg` | C / C++ | [C/C++](https://marketplace.visualstudio.com/items?itemName=ms-vscode.cpptools) |
 | `node` | Node.js / Electron | Built-in |
 
+> On your first debug session, if the extension for the selected `debuggerType` isn't installed, WinApp offers to install it and continues the session automatically — no manual reload needed in most cases. If no `debuggerType` is set and none is installed yet, WinApp lets you pick the debugger that matches your project (C#, C/C++, or built-in Node.js/Electron).
+
 **Example `launch.json`:**
 
 ```jsonc
@@ -158,7 +160,7 @@ The extension provides a **custom `winapp` debug type** that launches your app w
 |----------|------|---------|-------------|
 | `inputFolder` | string | | Path to the build output folder containing your app binaries (e.g., `${workspaceFolder}/bin/Debug/net8.0-windows10.0.22621`). If not set, you will be prompted to select a folder. |
 | `manifest` | string | | Path to the `AppxManifest.xml` file. If not set, the CLI auto-detects from the input folder or current directory. |
-| `debuggerType` | string | `coreclr` | Underlying debugger to use (`coreclr`, `cppvsdbg`, or `node`). |
+| `debuggerType` | string | | Optional underlying debugger override (`coreclr`, `cppvsdbg`, or `node`). If omitted, WinApp reuses an installed debugger or prompts you to pick one. |
 | `workingDirectory` | string | workspace folder | Working directory for the application. |
 | `args` | string | | Command-line arguments to pass to the application. |
 | `outputAppxDirectory` | string | | Output directory for the loose-layout package. Defaults to an `AppX` folder inside the input folder. |

package.json

@@ -163,8 +163,12 @@
               },
               "debuggerType": {
                 "type": "string",
-                "description": "The underlying debugger to use (e.g., 'coreclr', 'cppvsdbg')",
-                "default": "coreclr"
+                "enum": [
+                  "coreclr",
+                  "cppvsdbg",
+                  "node"
+                ],
+                "description": "Optional override for the underlying debugger to use. Omit to let WinApp reuse an installed debugger or prompt you to pick one ('coreclr', 'cppvsdbg', or 'node')."
               },
               "workingDirectory": {
                 "type": "string",
@@ -195,8 +199,7 @@
             "body": {
               "type": "winapp",
               "request": "launch",
-              "name": "WinApp: Launch and Attach",
-              "debuggerType": "coreclr"
+              "name": "WinApp: Launch and Attach"
             }
           }
         ]
@@ -216,7 +219,7 @@
     "clean": "node -e \"require('fs').rmSync('bin', {recursive: true, force: true}); require('fs').rmSync('out', {recursive: true, force: true}); require('fs').rmSync('dist', {recursive: true, force: true});\"",
     "download-cli": "pwsh -NoProfile -Command \"& ./scripts/download-cli.ps1\"",
     "download-cli:latest": "pwsh -NoProfile -Command \"& ./scripts/download-cli.ps1 -Tag latest\"",
-    "test:unit": "tsc -p ./ && node -e \"require('fs').cpSync('src/test/fixtures','out/test/fixtures',{recursive:true})\" && mocha out/test/project-detection.test.js && npx tsx --test src/test/extension-field-validator.test.ts src/test/extension-templates.test.ts src/test/manifest-edge-cases.test.ts src/test/manifest-parser.test.ts src/test/manifest-validator.test.ts src/test/project-resolver.test.ts src/test/redos-prevention.test.ts src/test/xml-utils.test.ts src/test/shell-escape.test.ts"
+    "test:unit": "tsc -p ./ && node -e \"require('fs').cpSync('src/test/fixtures','out/test/fixtures',{recursive:true})\" && mocha out/test/project-detection.test.js && npx tsx --test src/test/debugger-resolver.test.ts src/test/extension-field-validator.test.ts src/test/extension-templates.test.ts src/test/manifest-edge-cases.test.ts src/test/manifest-parser.test.ts src/test/manifest-validator.test.ts src/test/project-resolver.test.ts src/test/redos-prevention.test.ts src/test/xml-utils.test.ts src/test/shell-escape.test.ts"
   },
   "dependencies": {
     "@xmldom/xmldom": "^0.9.9",

src/debugger-resolver.ts

@@ -0,0 +1,55 @@
+export interface DebuggerExtensionRequirement {
+	id: string;
+	name: string;
+}
+
+/**
+ * Maps debugger types to the VS Code extensions that provide them.
+ */
+export const DEBUGGER_EXTENSION_REQUIREMENTS: Record<string, DebuggerExtensionRequirement> = {
+	'coreclr': { id: 'ms-dotnettools.csharp', name: 'C# (ms-dotnettools.csharp)' },
+	'cppvsdbg': { id: 'ms-vscode.cpptools', name: 'C/C++ (ms-vscode.cpptools)' },
+};
+
+/**
+ * Debugger types to consider (in preference order) when a launch configuration
+ * doesn't specify one, and we need to reuse an already-installed extension.
+ */
+export const DEFAULT_DEBUGGER_CANDIDATES: string[] = ['coreclr', 'cppvsdbg'];
+
+export const DEBUGGER_CHOICE_LABELS = {
+	installCsharp: 'Install C# (.NET)',
+	installCpp: 'Install C/C++',
+	useNode: 'Use Node.js / Electron (built-in)'
+} as const;
+
+export function getDebuggerExtensionRequirement(debuggerType: string): DebuggerExtensionRequirement | undefined {
+	return DEBUGGER_EXTENSION_REQUIREMENTS[debuggerType];
+}
+
+export function chooseInstalledDebuggerType(
+	installedExtensionIds: Iterable<string>,
+	candidates: readonly string[] = DEFAULT_DEBUGGER_CANDIDATES
+): string | undefined {
+	const installed = new Set([...installedExtensionIds].map(id => id.toLowerCase()));
+	for (const candidate of candidates) {
+		const requirement = getDebuggerExtensionRequirement(candidate);
+		if (requirement && installed.has(requirement.id.toLowerCase())) {
+			return candidate;
+		}
+	}
+	return undefined;
+}
+
+export function getDebuggerTypeFromChoice(choice: string | undefined): string | undefined {
+	if (choice === DEBUGGER_CHOICE_LABELS.installCsharp) {
+		return 'coreclr';
+	}
+	if (choice === DEBUGGER_CHOICE_LABELS.installCpp) {
+		return 'cppvsdbg';
+	}
+	if (choice === DEBUGGER_CHOICE_LABELS.useNode) {
+		return 'node';
+	}
+	return undefined;
+}