fix(dev): Q dev handle no change required (#5723)

Problem

* Q dev won't be able to generate code for unrelated prompts. (e.g.
explain the code)
* It would be a bad CX if Q fail to generate code without guiding users
the proper use cases.

Solution

* Handle no code change required explicitly.
* Allow users to provide more details


https://github.com/user-attachments/assets/cf593cea-cd4d-4b29-9142-d5810d46709c

Author: chengoramazon

packages/amazonq/.changes/next-release/Bug Fix-ff32752d-fa0b-4d38-b719-68eb3c9ddca6.json

@@ -0,0 +1,4 @@
+{
+	"type": "Bug Fix",
+	"description": "Q dev handle no change required"
+}

packages/core/package.nls.json

@@ -273,6 +273,7 @@
     "AWS.amazonq.featureDev.error.illegalStateTransition": "Illegal transition between states, restart the conversation",
     "AWS.amazonq.featureDev.error.prepareRepoFailedError": "Sorry, I ran into an issue while trying to upload your code. Please try again.",
     "AWS.amazonq.featureDev.error.promptRefusalException": "I'm sorry, I can't generate code for your request. Please make sure your message and code files comply with the <a href=\"https://aws.amazon.com/machine-learning/responsible-ai/policy/\">AWS Responsible AI Policy.</a>",
+    "AWS.amazonq.featureDev.error.noChangeRequiredException": "I’m sorry, I ran into an issue while trying to generate your code.\n\n- `/dev` can generate code to make a change in your project. Provide a detailed description of the new feature or code changes you want to make, including the specifics of what the code should achieve.\n\n- To ask me to explain, debug, or optimize your code, you can close this chat tab to start a new conversation.",
     "AWS.amazonq.featureDev.error.zipFileError": "The zip file is corrupted",
     "AWS.amazonq.featureDev.error.codeIterationLimitError": "Sorry, you've reached the quota for number of iterations on code generation. You can insert this code in your files or discuss a new plan. For more information on quotas, see the <a href=\"https://docs.aws.amazon.com/amazonq/latest/qdeveloper-ug/software-dev.html#quotas\" target=\"_blank\">Amazon Q Developer documentation.</a>",
     "AWS.amazonq.featureDev.error.tabIdNotFoundError": "I'm sorry, I'm having technical difficulties at the moment. Please try again.",

packages/core/src/amazonq/webview/ui/quickActions/generator.ts

@@ -29,8 +29,7 @@ export class QuickActionGenerator {
                               {
                                   command: '/dev',
                                   placeholder: 'Describe your task or issue in as much detail as possible',
-                                  description:
-                                      'Plan and implement new functionality across multiple files in your workspace.',
+                                  description: 'Generate code to make a change in your project',
                               },
                           ]
                         : []),

packages/core/src/amazonqFeatureDev/controllers/chat/controller.ts

@@ -14,6 +14,7 @@ import {
     ContentLengthError,
     FeatureDevServiceError,
     MonthlyConversationLimitError,
+    NoChangeRequiredException,
     PrepareRepoFailedError,
     PromptRefusalException,
     SelectedFolderNotInWorkspaceFolderError,
@@ -131,6 +132,11 @@ export class FeatureDevController {
                     this.initialExamples(data)
                     break
                 case FollowUpTypes.NewTask:
+                    this.messenger.sendAnswer({
+                        type: 'answer',
+                        tabID: data?.tabID,
+                        message: i18n('AWS.amazonq.featureDev.answer.newTaskChanges'),
+                    })
                     return this.newTask(data)
                 case FollowUpTypes.CloseSession:
                     return this.closeSession(data)
@@ -246,6 +252,15 @@ export class FeatureDevController {
             case ZipFileError.errorName:
                 this.messenger.sendErrorMessage(errorMessage, message.tabID, 0, session?.conversationIdUnsafe, true)
                 break
+            case NoChangeRequiredException.errorName:
+                this.messenger.sendAnswer({
+                    type: 'answer',
+                    tabID: message.tabID,
+                    message: err.message,
+                    canBeVoted: true,
+                })
+                // Allow users to re-work the task description.
+                return this.newTask(message)
             case CodeIterationLimitError.errorName:
                 this.messenger.sendAnswer({
                     type: 'answer',
@@ -319,7 +334,7 @@ export class FeatureDevController {
                 await this.onCodeGeneration(session, message.message, message.tabID)
             }
         } catch (err: any) {
-            this.processErrorChatMessage(err, message, session)
+            await this.processErrorChatMessage(err, message, session)
             // Lock the chat input until they explicitly click one of the follow ups
             this.messenger.sendChatInputEnabled(message.tabID, false)
         }
@@ -758,11 +773,7 @@ export class FeatureDevController {
         // Re-run the opening flow, where we check auth + create a session
         await this.tabOpened(message)
 
-        this.messenger.sendAnswer({
-            type: 'answer',
-            tabID: message.tabID,
-            message: i18n('AWS.amazonq.featureDev.answer.newTaskChanges'),
-        })
+        this.messenger.sendChatInputEnabled(message.tabID, true)
         this.messenger.sendUpdatePlaceholder(message.tabID, i18n('AWS.amazonq.featureDev.placeholder.describe'))
     }
 

packages/core/src/amazonqFeatureDev/errors.ts

@@ -66,6 +66,15 @@ export class PromptRefusalException extends ToolkitError {
     }
 }
 
+export class NoChangeRequiredException extends ToolkitError {
+    static errorName = 'NoChangeRequiredException'
+    constructor() {
+        super(i18n('AWS.amazonq.featureDev.error.noChangeRequiredException'), {
+            code: 'NoChangeRequiredException',
+        })
+    }
+}
+
 export class FeatureDevServiceError extends ToolkitError {
     static errorName = 'FeatureDevServiceError'
     constructor(message: string, code: string) {

packages/core/src/amazonqFeatureDev/session/sessionState.ts

@@ -13,7 +13,12 @@ import { telemetry } from '../../shared/telemetry/telemetry'
 import { VirtualFileSystem } from '../../shared/virtualFilesystem'
 import { VirtualMemoryFile } from '../../shared/virtualMemoryFile'
 import { featureDevScheme } from '../constants'
-import { FeatureDevServiceError, IllegalStateTransition, PromptRefusalException } from '../errors'
+import {
+    FeatureDevServiceError,
+    IllegalStateTransition,
+    NoChangeRequiredException,
+    PromptRefusalException,
+} from '../errors'
 import {
     CodeGenerationStatus,
     CurrentWsFolders,
@@ -208,6 +213,9 @@ abstract class CodeGenBase {
                             throw new PromptRefusalException()
                         }
                         case codegenResult.codeGenerationStatusDetail?.includes('EmptyPatch'): {
+                            if (codegenResult.codeGenerationStatusDetail?.includes('NO_CHANGE_REQUIRED')) {
+                                throw new NoChangeRequiredException()
+                            }
                             throw new FeatureDevServiceError(
                                 i18n('AWS.amazonq.featureDev.error.codeGen.default'),
                                 'EmptyPatchException'

packages/core/src/test/amazonqFeatureDev/controllers/chat/controller.test.ts

@@ -13,10 +13,14 @@ import { CurrentWsFolders, FollowUpTypes, NewFileInfo, DeletedFileInfo } from '.
 import { Session } from '../../../../amazonqFeatureDev/session/session'
 import { Prompter } from '../../../../shared/ui/prompter'
 import { assertTelemetry, toFile } from '../../../testUtil'
-import { SelectedFolderNotInWorkspaceFolderError } from '../../../../amazonqFeatureDev/errors'
+import {
+    NoChangeRequiredException,
+    SelectedFolderNotInWorkspaceFolderError,
+} from '../../../../amazonqFeatureDev/errors'
 import { CodeGenState, PrepareCodeGenState } from '../../../../amazonqFeatureDev/session/sessionState'
 import { FeatureDevClient } from '../../../../amazonqFeatureDev/client/featureDev'
 import { createAmazonQUri } from '../../../../amazonq/commons/diff'
+import { AuthUtil } from '../../../../codewhisperer'
 
 let mockGetCodeGeneration: sinon.SinonStub
 describe('Controller', () => {
@@ -68,6 +72,12 @@ describe('Controller', () => {
     beforeEach(async () => {
         controllerSetup = await createController()
         session = await createSession({ messenger: controllerSetup.messenger, conversationID, tabID, uploadID })
+
+        sinon.stub(AuthUtil.instance, 'getChatAuthState').resolves({
+            codewhispererCore: 'connected',
+            codewhispererChat: 'connected',
+            amazonQ: 'connected',
+        })
     })
 
     afterEach(() => {
@@ -357,4 +367,41 @@ describe('Controller', () => {
             })
         })
     })
+
+    describe('processUserChatMessage', function () {
+        async function fireChatMessage() {
+            const getSessionStub = sinon.stub(controllerSetup.sessionStorage, 'getSession').resolves(session)
+
+            controllerSetup.emitters.processHumanChatMessage.fire({
+                tabID,
+                conversationID,
+                message: 'test message',
+            })
+
+            // Wait until the controller has time to process the event
+            await waitUntil(() => {
+                return Promise.resolve(getSessionStub.callCount > 0)
+            }, {})
+        }
+
+        describe('processErrorChatMessage', function () {
+            it('should handle NoChangeRequiredException', async function () {
+                const noChangeRequiredException = new NoChangeRequiredException()
+                sinon.stub(session, 'preloader').throws(noChangeRequiredException)
+                const sendAnswerSpy = sinon.stub(controllerSetup.messenger, 'sendAnswer')
+
+                await fireChatMessage()
+
+                assert.strictEqual(
+                    sendAnswerSpy.calledWith({
+                        type: 'answer',
+                        tabID,
+                        message: noChangeRequiredException.message,
+                        canBeVoted: true,
+                    }),
+                    true
+                )
+            })
+        })
+    })
 })