fix(windows): devtools auto-start

Author: triniwiz

lib/common/definitions/mobile.d.ts

@@ -366,6 +366,12 @@ declare global {
 
 		interface IStartApplicationData extends IApplicationData {
 			waitForDebugger?: boolean;
+			/**
+			 * True when launching as part of a debug session (`ns debug`), regardless of --debug-brk.
+			 * Windows uses this to signal the host to start the inspector (via a sentinel file);
+			 * a plain `ns run` leaves it unset so the inspector/devtools server is never created.
+			 */
+			debugMode?: boolean;
 		}
 
 		interface IInstallAppData extends IApplicationData {

lib/common/mobile/windows/windows-application-manager.ts

@@ -224,8 +224,12 @@ export class WindowsApplicationManager extends ApplicationManagerBase {
 		} else {
 			// PFN already cached from the pre-resolve above; no extra round-trip.
 			const pfn = this._packageFamilyNames.get(appData.appId) ?? appData.appId;
+			// Any debug session starts the inspector; --debug-brk additionally signals break-on-start.
+			if (appData.debugMode) {
+				this._writeMarker(pfn, "ns-inspector");
+			}
 			if (appData.waitForDebugger) {
-				this._writeDebugBreakMarker(pfn);
+				this._writeMarker(pfn, "ns-debugbreak");
 			}
 			// UWP apps are launched via shell:AppsFolder\<PFN>!<ApplicationId>.
 			// The ApplicationId comes from the <Application Id="..."> attribute in the manifest.
@@ -320,22 +324,19 @@ export class WindowsApplicationManager extends ApplicationManagerBase {
 		return this._packageFamilyNames.get(appId) ?? appId;
 	}
 
-	private _writeDebugBreakMarker(pfn: string): void {
+	// Writes a sentinel file into the packaged app's LocalState that the C# host consumes on launch
+	// (RuntimeHost.ConsumeMarker). Used to signal the inspector ("ns-inspector") and break-on-start
+	// ("ns-debugbreak") out-of-band, since a UWP app launched via shell:AppsFolder inherits no env.
+	private _writeMarker(pfn: string, name: string): void {
 		const localAppData = process.env.LOCALAPPDATA;
 		if (!localAppData) return;
-		const markerPath = path.join(
-			localAppData,
-			"Packages",
-			pfn,
-			"LocalState",
-			"ns-debugbreak",
-		);
+		const markerPath = path.join(localAppData, "Packages", pfn, "LocalState", name);
 		try {
 			fs.mkdirSync(path.dirname(markerPath), { recursive: true });
 			fs.writeFileSync(markerPath, "", "utf8");
-			this.$logger.info(`[Windows] Debug break marker: ${markerPath}`);
+			this.$logger.info(`[Windows] Wrote ${name} marker: ${markerPath}`);
 		} catch (e) {
-			this.$logger.warn(`[Windows] Could not write debug break marker: ${e}`);
+			this.$logger.warn(`[Windows] Could not write ${name} marker: ${e}`);
 		}
 	}
 }

lib/controllers/run-controller.ts

@@ -275,6 +275,9 @@ export class RunController extends EventEmitter implements IRunController {
 		const debugOptions = deviceDescriptor.debugOptions || {};
 
 		liveSyncResultInfo.waitForDebugger = !!debugOptions.debugBrk;
+		// Any debug session (attach or --debug-brk) should bring up the inspector. Windows keys the
+		// inspector start off this (a plain `ns run` never sets it, so the inspector stays off).
+		liveSyncResultInfo.debugMode = true;
 		liveSyncResultInfo.forceRefreshWithSocket = true;
 
 		const refreshInfo = await this.refreshApplicationWithoutDebug(

lib/definitions/livesync.d.ts

@@ -252,6 +252,8 @@ declare global {
 		modifiedFilesData: Mobile.ILocalToDevicePathData[];
 		isFullSync: boolean;
 		waitForDebugger?: boolean;
+		/** True for any `ns debug` session (attach or --debug-brk); drives the Windows inspector start. */
+		debugMode?: boolean;
 		deviceAppData: Mobile.IDeviceAppData;
 		didRecover?: boolean;
 		forceRefreshWithSocket?: boolean;

lib/services/livesync/windows-device-livesync-service.ts

@@ -31,6 +31,7 @@ export class WindowsDeviceLiveSyncService
 			projectName: projectData.projectName,
 			projectDir: projectData.projectDir,
 			waitForDebugger: _liveSyncInfo?.waitForDebugger,
+			debugMode: _liveSyncInfo?.debugMode,
 		} as Mobile.IStartApplicationData);
 	}