debug: try to always create a launch.json as a last resort

fixes #19302

src/vs/workbench/parts/debug/browser/debugActions.ts

@@ -127,14 +127,18 @@ export class StartAction extends AbstractDebugAction {
 		}
 
 		const configuration = manager.getConfiguration(configName);
-		return manager.getStartSessionCommand(configuration ? configuration.type : undefined).then(command => {
-			if (command) {
-				return this.commandService.executeCommand(command, configuration || this.getDefaultConfiguration());
+		return manager.getStartSessionCommand(configuration ? configuration.type : undefined).then(commandAndType => {
+			if (commandAndType && commandAndType.command) {
+				return this.commandService.executeCommand(commandAndType.command, configuration || this.getDefaultConfiguration());
 			}
 
 			if (configName) {
 				return this.commandService.executeCommand('_workbench.startDebug', configName);
 			}
+
+			if (this.contextService.getWorkspace()) {
+				return manager.openConfigFile(false, commandAndType ? commandAndType.type : undefined);
+			}
 		});
 	}
 

src/vs/workbench/parts/debug/common/debug.ts

@@ -360,9 +360,9 @@ export interface IConfigurationManager {
 	getCompound(name: string): ICompound;
 
 	/**
-	 * Opens the launch.json file
+	 * Opens the launch.json file. Creates if it does not exist.
 	 */
-	openConfigFile(sideBySide: boolean): TPromise<IEditor>;
+	openConfigFile(sideBySide: boolean, type?: string): TPromise<IEditor>;
 
 	/**
 	 * Returns true if breakpoints can be set for a given editor model. Depends on mode.
@@ -374,7 +374,7 @@ export interface IConfigurationManager {
 	 * If no type is specified will try to automatically pick an adapter by looking at
 	 * the active editor language and matching it against the "languages" contribution of an adapter.
 	 */
-	getStartSessionCommand(type?: string): TPromise<string>;
+	getStartSessionCommand(type?: string): TPromise<{ command: string, type: string }>;
 }
 
 // Debug service interfaces

src/vs/workbench/parts/debug/electron-browser/debugConfigurationManager.ts

@@ -342,12 +342,12 @@ export class ConfigurationManager implements debug.IConfigurationManager {
 		return this.configurationResolverService.resolveInteractiveVariables(result, adapter ? adapter.variables : null);
 	}
 
-	public openConfigFile(sideBySide: boolean): TPromise<IEditor> {
+	public openConfigFile(sideBySide: boolean, type?: string): TPromise<IEditor> {
 		const resource = uri.file(paths.join(this.contextService.getWorkspace().resource.fsPath, '/.vscode/launch.json'));
 		let configFileCreated = false;
 
 		return this.fileService.resolveContent(resource).then(content => true, err =>
-			this.guessAdapter().then(adapter => adapter ? adapter.getInitialConfigurationContent() : undefined)
+			this.guessAdapter(type).then(adapter => adapter ? adapter.getInitialConfigurationContent() : undefined)
 				.then(content => {
 					if (!content) {
 						return false;
@@ -375,10 +375,13 @@ export class ConfigurationManager implements debug.IConfigurationManager {
 			});
 	}
 
-	public getStartSessionCommand(type?: string): TPromise<string> {
+	public getStartSessionCommand(type?: string): TPromise<{ command: string, type: string }> {
 		return this.guessAdapter(type).then(adapter => {
 			if (adapter) {
-				return adapter.startSessionCommand;
+				return {
+					command: adapter.startSessionCommand,
+					type: adapter.type
+				};
 			}
 		});
 	}