Handle debugger lifecycle

src/breakpoints/body.tsx

@@ -94,9 +94,9 @@ const BreakpointCellComponent = ({
         .sort((a, b) => {
           return a.line - b.line;
         })
-        .map((breakpoint: IDebugger.IBreakpoint) => (
+        .map((breakpoint: IDebugger.IBreakpoint, index) => (
           <BreakpointComponent
-            key={breakpoint.source.path + breakpoint.line}
+            key={breakpoint.source.path + index}
             breakpoint={breakpoint}
             model={model}
           />

src/debugger.ts

@@ -96,6 +96,9 @@ export namespace Debugger {
     readonly sources: Sources.Model;
 
     dispose(): void {
+      if (this._isDisposed) {
+        return;
+      }
       this._isDisposed = true;
       this._disposed.emit();
     }

src/handlers/editor.ts

@@ -43,7 +43,7 @@ export class EditorHandler implements IDisposable {
       this.sendEditorBreakpoints();
     }, this);
 
-    this.setup();
+    this.setupEditor();
   }
 
   isDisposed: boolean;
@@ -79,9 +79,9 @@ export class EditorHandler implements IDisposable {
       return;
     }
     this._editorMonitor.dispose();
-    this.removeGutterClick();
-    Signal.clearData(this);
+    this.clearEditor();
     this.isDisposed = true;
+    Signal.clearData(this);
   }
 
   protected sendEditorBreakpoints() {
@@ -104,7 +104,7 @@ export class EditorHandler implements IDisposable {
     );
   }
 
-  protected setup() {
+  protected setupEditor() {
     if (!this._editor || this._editor.isDisposed) {
       return;
     }
@@ -120,11 +120,13 @@ export class EditorHandler implements IDisposable {
     editor.editor.on('gutterClick', this.onGutterClick);
   }
 
-  protected removeGutterClick() {
+  protected clearEditor() {
     if (!this._editor || this._editor.isDisposed) {
       return;
     }
     const editor = this._editor as CodeMirrorEditor;
+    editor.setOption('lineNumbers', false);
+    editor.editor.setOption('gutters', []);
     editor.editor.off('gutterClick', this.onGutterClick);
   }
 

src/handlers/file.ts

@@ -1,6 +1,8 @@
 // Copyright (c) Jupyter Development Team.
 // Distributed under the terms of the Modified BSD License.
 
+import { DocumentWidget } from '@jupyterlab/docregistry';
+
 import { FileEditor } from '@jupyterlab/fileeditor';
 
 import { IDisposable } from '@phosphor/disposable';
@@ -14,7 +16,7 @@ import { IDebugger } from '../tokens';
 export class FileHandler implements IDisposable {
   constructor(options: DebuggerFileHandler.IOptions) {
     this.debuggerService = options.debuggerService;
-    this.fileEditor = options.widget;
+    this.fileEditor = options.widget.content;
 
     this.editorHandler = new EditorHandler({
       debuggerService: this.debuggerService,
@@ -41,6 +43,6 @@ export class FileHandler implements IDisposable {
 export namespace DebuggerFileHandler {
   export interface IOptions {
     debuggerService: IDebugger;
-    widget: FileEditor;
+    widget: DocumentWidget<FileEditor>;
   }
 }