Dap ux enhancements

package.json

@@ -25,7 +25,8 @@
   ],
   "activationEvents": [
     "onLanguage:noir",
-    "onStartupFinished"
+    "onStartupFinished",
+    "onDebug"
   ],
   "main": "./out/extension",
   "contributes": {

src/debugger.ts

@@ -0,0 +1,126 @@
+import {
+  debug,
+  window,
+  workspace,
+  DebugAdapterDescriptorFactory,
+  DebugSession,
+  DebugAdapterExecutable,
+  DebugAdapterDescriptor,
+  ExtensionContext,
+  OutputChannel,
+  DebugConfigurationProvider,
+  CancellationToken,
+  DebugConfiguration,
+  ProviderResult,
+} from 'vscode';
+
+import { spawn } from 'child_process';
+import findNargo from './find-nargo';
+import findNearestPackageFrom from './find-nearest-package';
+
+let outputChannel: OutputChannel;
+
+export function activateDebugger(context: ExtensionContext) {
+  outputChannel = window.createOutputChannel('NoirDebugger');
+
+  context.subscriptions.push(
+    debug.registerDebugAdapterDescriptorFactory('noir', new NoirDebugAdapterDescriptorFactory()),
+    debug.registerDebugConfigurationProvider('noir', new NoirDebugConfigurationProvider()),
+    debug.onDidTerminateDebugSession(() => {
+      outputChannel.appendLine("Debug session ended.");
+    }),
+  );
+}
+
+export class NoirDebugAdapterDescriptorFactory implements DebugAdapterDescriptorFactory {
+  async createDebugAdapterDescriptor(
+    _session: DebugSession,
+    _executable: DebugAdapterExecutable,
+  ): ProviderResult<DebugAdapterDescriptor> {
+    const config = workspace.getConfiguration('noir');
+
+    const configuredNargoPath = config.get<string | undefined>('nargoPath');
+    const nargoPath = configuredNargoPath || findNargo();
+
+    return new DebugAdapterExecutable(nargoPath, ['dap']);
+  }
+}
+
+class NoirDebugConfigurationProvider implements DebugConfigurationProvider {
+  async resolveDebugConfiguration(folder: WorkspaceFolder | undefined, config: DebugConfiguration, token?: CancellationToken): ProviderResult<DebugConfiguration> {
+    if (config.program || config.request == 'attach')
+      return config;
+
+    if (window.activeTextEditor?.document.languageId != 'noir')
+      return window.showInformationMessage("Select a Noir file to debug");
+
+    const currentFilePath = window.activeTextEditor.document.uri.fsPath;
+    let currentProjectFolder = findNearestPackageFrom(currentFilePath);
+
+    const workspaceConfig = workspace.getConfiguration('noir');
+    const nargoPath = workspaceConfig.get<string | undefined>('nargoPath') || findNargo();
+
+    outputChannel.clear();
+    outputChannel.appendLine(`Using nargo at ${nargoPath}`);
+    outputChannel.appendLine("Compiling Noir project...");
+    outputChannel.appendLine("");
+
+    // Run Nargo's DAP in "pre-flight mode", which test runs
+    // the DAP initialization code without actually starting the DAP server.
+    // This lets us gracefully handle errors that happen *before*
+    // the DAP loop is established, which otherwise are considered
+    // "out of band".
+    const preflightCheck = spawn(nargoPath, [
+      'dap',
+      '--preflight-check',
+      '--preflight-project-folder',
+      currentProjectFolder
+    ]);
+
+    // Create a promise to block until the preflight check child process
+    // ends.
+    let ready: (r: Boolean) => void;
+    const preflightCheckMonitor = new Promise((resolve) => ready = resolve);
+
+    preflightCheck.stderr.on('data', ev_buffer => preflightCheckPrinter(ev_buffer, outputChannel));
+    preflightCheck.stdout.on('data', ev_buffer => preflightCheckPrinter(ev_buffer, outputChannel));
+    preflightCheck.on('data', ev_buffer => preflightCheckPrinter(ev_buffer, outputChannel));
+    preflightCheck.on('exit', async code => {
+      if (code !== 0) {
+        outputChannel.appendLine(`Exited with code ${code}`);
+      }
+      ready(code == 0);
+    });
+
+    if (!await preflightCheckMonitor) {
+      outputChannel.show();
+      throw new Error("Error launching debugger. Please inspect the Output pane for more details.");
+    } else {
+      outputChannel.appendLine("Starting debugger session...");
+    }
+
+    return {
+      type: 'noir',
+      name: 'Noir binary package',
+      request: 'launch',
+      program: currentFilePath,
+      projectFolder: currentProjectFolder,
+    }
+  }
+}
+
+/**
+ * Takes stderr or stdout output from the Nargo's DAP
+ * preflight check and formats it in an Output pane friendly way,
+ * by removing all special characters.
+ *
+ * Note: VS Code's output panes only support plain text.
+ *
+ */
+function preflightCheckPrinter(buffer: Buffer, output: OutputChannel) {
+  const formattedOutput = buffer.toString()
+        .replace(/\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])/g, '')
+        .replace(/[^ -~\n\t]/g, '');
+
+  output.appendLine(formattedOutput);
+}

src/extension.ts

@@ -20,7 +20,6 @@
   window,
   workspace,
   commands,
-  debug,
   ExtensionContext,
   Disposable,
   TextDocument,
@@ -35,39 +34,19 @@
   TaskPanelKind,
   TaskGroup,
   ProcessExecution,
-  window,
-  ProgressLocation,
-  DebugAdapterDescriptorFactory,
-  DebugConfigurationProvider,
-  CancellationToken,
-  DebugConfiguration,
-  DebugAdapterDescriptor,
-  DebugAdapterExecutable,
-  DebugSession,
-  ProviderResult,
+  ProgressLocation,  
 } from 'vscode';
 
+import { activateDebugger } from './debugger';
+
 import { languageId } from './constants';
 import Client from './client';
 import findNargo from './find-nargo';
-import findNearestPackageFrom from './find-nearest-package';
 import { lspClients, editorLineDecorationManager } from './noir';
 
 const activeCommands: Map<string, Disposable> = new Map();
 
-class NoirDebugAdapterDescriptorFactory implements DebugAdapterDescriptorFactory {
-  createDebugAdapterDescriptor(
-    _session: DebugSession,
-    _executable: DebugAdapterExecutable,
-  ): ProviderResult<DebugAdapterDescriptor> {
-    const config = workspace.getConfiguration('noir');
-
-    const configuredNargoPath = config.get<string | undefined>('nargoPath');
-    const nargoPath = configuredNargoPath || findNargo();
-
-    return new DebugAdapterExecutable(nargoPath, ['dap']);
-  }
-}
+let outputChannel: OutputChannel;
 
 const activeMutex: Set<string> = new Set();
 
@@ -359,40 +338,11 @@
     context.subscriptions.push(disposable);
   }
 
-  context.subscriptions.push(
-    debug.registerDebugAdapterDescriptorFactory('noir', new NoirDebugAdapterDescriptorFactory()),
-  );
-
-  context.subscriptions.push(
-    debug.registerDebugConfigurationProvider('noir', new NoirDebugConfigurationProvider()),
-  );
+  activateDebugger(context);
 }
 
 export async function deactivate(): Promise<void> {
   for (const client of lspClients.values()) {
     await client.stop();
   }
-}
-
-class NoirDebugConfigurationProvider implements DebugConfigurationProvider {
-  resolveDebugConfiguration(folder: WorkspaceFolder | undefined, config: DebugConfiguration, token?: CancellationToken): ProviderResult<DebugConfiguration> {
-    if (config.program || config.request == 'attach')
-      return config;
-
-    if (window.activeTextEditor?.document.languageId != 'noir')
-      return window.showInformationMessage("Select a Noir file to debug").then(_ => {
-        return null;
-      });
-
-    const currentFilePath = window.activeTextEditor.document.uri.fsPath;
-    let currentProject = findNearestPackageFrom(currentFilePath);
-
-    return {
-      type: 'noir',
-      name: 'Noir binary package',
-      request: 'launch',
-      program: currentFilePath,
-      projectFolder: currentProject,
-    }
-  }
-}
+}