Enable debugger on kernel change

packages/script-debugger/src/index.ts

@@ -93,10 +93,8 @@ const scriptEditorDebuggerExtension: JupyterFrontEndPlugin<void> = {
             activeSessions[sessionModel.id] = sessionConnection;
           }
           if (sessionModel.kernel?.name !== kernelSelection) {
-            // New kernel selection detected, restart session connection for new kernel
-            await shutdownSession(sessionConnection);
-
-            sessionConnection = await startSession(kernelSelection, path);
+            // New kernel selection detected, update session connection
+            await changeKernel(sessionConnection, kernelSelection);
             sessionModel = await sessions.findByPath(path);
             if (sessionConnection && sessionModel) {
               activeSessions[sessionModel.id] = sessionConnection;
@@ -177,15 +175,16 @@ const scriptEditorDebuggerExtension: JupyterFrontEndPlugin<void> = {
       return sessionConnection;
     };
 
-    const shutdownSession = async (
-      sessionConnection: Session.ISessionConnection
+    const changeKernel = async (
+      sessionConnection: Session.ISessionConnection,
+      kernelSelection: string
     ): Promise<void> => {
       try {
-        const kernelName = sessionConnection.kernel?.name;
-        await sessionConnection.shutdown();
-        console.log(`${kernelName} kernel shut down.`);
+        const prev = sessionConnection.kernel?.name;
+        await sessionConnection.changeKernel({ name: kernelSelection });
+        console.log(`Kernel change from ${prev} to ${kernelSelection}`);
       } catch (error) {
-        console.warn('Exception: shutdown = ' + JSON.stringify(error));
+        console.warn('Exception: change kernel = ' + JSON.stringify(error));
       }
     };
   }

packages/script-editor/src/ScriptEditorController.ts

@@ -75,13 +75,18 @@ export class ScriptEditorController {
       return kernelSpecs.default;
     }
 
+    return this.getFirstKernelName(language);
+  };
+
+  getFirstKernelName = async (language: string): Promise<string> => {
     const specsByLang = await this.getKernelSpecsByLanguage(language);
-    const first = (k: any): any => k[Object.keys(k)[0]];
-    let kernelName = '';
+
+    const empty = '';
     if (specsByLang && Object.keys(specsByLang.kernelspecs).length !== 0) {
-      kernelName = first(specsByLang.kernelspecs.name);
+      const [key, value]: any = Object.entries(specsByLang.kernelspecs)[0];
+      return value.name ?? key;
     }
-    return kernelName;
+    return empty;
   };
 
   /**

packages/script-editor/src/ScriptRunner.ts

@@ -203,6 +203,7 @@ export class ScriptRunner {
         kernel &&
           (await KernelAPI.interruptKernel(kernel.id, kernel.serverSettings));
         console.log(kernel?.name + ' kernel interrupted.');
+        this.disableButton(false);
       } catch (e) {
         console.log('Exception: kernel interrupt = ' + JSON.stringify(e));
       }

packages/script-editor/src/test/script-editor.spec.ts

@@ -18,6 +18,7 @@ import { JupyterServer } from '@jupyterlab/testutils';
 
 import { ScriptEditorController } from '../ScriptEditorController';
 import { ScriptRunner } from '../ScriptRunner';
+
 jest.setTimeout(3 * 60 * 1000);
 
 const server = new JupyterServer();
@@ -33,16 +34,28 @@ afterAll(async () => {
 
 describe('@elyra/script-editor', () => {
   describe('ScriptEditorController', () => {
-    describe('#getKernelSpecs', () => {
+    let controller: ScriptEditorController;
+
+    beforeEach(async () => {
+      controller = new ScriptEditorController();
+    });
+
+    describe('#kernelSpecs', () => {
       it('should get Python kernel specs', async () => {
-        const controller = new ScriptEditorController();
         const kernelSpecs = await controller.getKernelSpecsByLanguage(language);
-        for (const [key, value] of Object.entries(
-          kernelSpecs?.kernelspecs ?? []
-        )) {
-          expect(key).toContain(language);
-          expect(value?.language).toContain(language);
-        }
+        Object.entries(kernelSpecs?.kernelspecs ?? []).forEach(([, value]) =>
+          expect(value?.language).toContain(language)
+        );
+      });
+    });
+
+    describe('#debuggerAvailable', () => {
+      it('should return true for kernels that have support for debugging', async () => {
+        let available = await controller.debuggerAvailable('python3');
+        expect(available).toBe(true);
+
+        available = await controller.debuggerAvailable('test');
+        expect(available).toBe(false);
       });
     });
   });
@@ -56,9 +69,7 @@ describe('@elyra/script-editor', () => {
       beforeEach(async () => {
         runner = new ScriptRunner((x: boolean): void => console.log(x));
         const controller = new ScriptEditorController();
-        const kernelSpecs = await controller.getKernelSpecsByLanguage(language);
-        kernelName =
-          Object.values(kernelSpecs?.kernelspecs ?? [])[0]?.name || '';
+        kernelName = await controller.getDefaultKernel(language);
       });
 
       it('should start a kernel session', async () => {