fix #698, debug single file without launch.json

Author: DonJayamanne

package.json

@@ -257,6 +257,10 @@
 		"debuggers": [{
 			"type": "python",
 			"label": "Python",
+			"languages": [
+				"python"
+			],
+			"startSessionCommand": "python.python-debug.startSession",
 			"enableBreakpointsFor": {
 				"languageIds": [
 					"python",

src/client/extension.ts

@@ -27,7 +27,7 @@ import { WorkspaceSymbols } from './workspaceSymbols/main';
 import { BlockFormatProviders } from './typeFormatters/blockFormatProvider';
 import * as os from 'os';
 import * as fs from 'fs';
-
+import { activateSingleFileDebug } from './singleFileDebug';
 
 const PYTHON: vscode.DocumentFilter = { language: 'python', scheme: 'file' };
 let unitTestOutChannel: vscode.OutputChannel;
@@ -65,7 +65,7 @@ export function activate(context: vscode.ExtensionContext) {
     context.subscriptions.push(vscode.commands.registerCommand(Commands.Start_REPL, () => {
         let term = vscode.window.createTerminal('Python', pythonSettings.pythonPath);
         term.show();
-        context.subscriptions.push(term);        
+        context.subscriptions.push(term);
     }));
 
     // Enable indentAction
@@ -117,6 +117,8 @@ export function activate(context: vscode.ExtensionContext) {
 
     const hepProvider = new HelpProvider();
     context.subscriptions.push(hepProvider);
+
+    context.subscriptions.push(activateSingleFileDebug());
 }
 
 // this method is called when your extension is deactivated
@@ -125,32 +127,32 @@ export function deactivate() {
 
 class PythonExt {
 
-	private _isDjangoProject: ContextKey;
+    private _isDjangoProject: ContextKey;
 
-	constructor() {
-		this._isDjangoProject = new ContextKey('python.isDjangoProject');
-		this._ensureState();
-	}
+    constructor() {
+        this._isDjangoProject = new ContextKey('python.isDjangoProject');
+        this._ensureState();
+    }
 
-	private _ensureState(): void {
-		// context: python.isDjangoProject
-		this._isDjangoProject.set(fs.existsSync(vscode.workspace.rootPath.concat("/manage.py")));
-	}
+    private _ensureState(): void {
+        // context: python.isDjangoProject
+        this._isDjangoProject.set(fs.existsSync(vscode.workspace.rootPath.concat("/manage.py")));
+    }
 }
 
-class ContextKey { 
- 	private _name: string; 
- 	private _lastValue: boolean;  
- 
- 	constructor(name:string) { 
- 		this._name = name; 
- 	}  
- 
- 	public set(value:boolean): void { 
- 		if (this._lastValue === value) { 
- 			return; 
- 		} 
- 		this._lastValue = value; 
- 		vscode.commands.executeCommand('setContext', this._name, this._lastValue); 
- 	} 
+class ContextKey {
+    private _name: string;
+    private _lastValue: boolean;
+
+    constructor(name: string) {
+        this._name = name;
+    }
+
+    public set(value: boolean): void {
+        if (this._lastValue === value) {
+            return;
+        }
+        this._lastValue = value;
+        vscode.commands.executeCommand('setContext', this._name, this._lastValue);
+    }
 } 

src/client/singleFileDebug.ts

@@ -0,0 +1,43 @@
+import * as vscode from 'vscode';
+import { dirname } from 'path';
+
+export function activateSingleFileDebug() {
+    return vscode.commands.registerCommand('python.python-debug.startSession', config => {
+
+        if (!config.request) { // if 'request' is missing interpret this as a missing launch.json
+            config.type = 'python';
+            config.name = 'Launch';
+            config.request = 'launch';
+            config.pythonPath = "python";
+            config.debugOptions = [
+                "WaitOnAbnormalExit",
+                "WaitOnNormalExit",
+                "RedirectOutput"
+            ];
+            config.stopOnEntry = true;
+            config.module = '';
+            config.args = [];
+            config.console = "integratedTerminal";
+            config.exceptionHandling = [];
+            config.env = null;
+
+            if (vscode.workspace.rootPath) {
+                config.cwd = vscode.workspace.rootPath;
+            }
+
+            if (!config.program) {
+                const editor = vscode.window.activeTextEditor;
+                if (editor && editor.document.languageId === 'python') {
+                    config.program = editor.document.fileName;
+                }
+            }
+
+            if (!config.cwd && config.program) {
+                // fall back if 'cwd' not known: derive it from 'program'
+                config.cwd = dirname(config.program);
+            }
+        }
+
+        vscode.commands.executeCommand('vscode.startDebug', config);
+    });
+}