fix(amazonq): file opening behavior on accepted changes (aws#6012)

## Problem
- when you accept an individual code change, it will bring up the file
window
- when you update the accepted file, both left and right of the window
reflects the changes you made immediately
- it should only show the changes made on the left, while the right
stays the same as the original suggested code change

## Solution
- updated the way vscode.diff is called when opening up the file such
that it is the actual file on the left, and the suggested code change
stays on the right

Author: kelvin-klchu

packages/amazonq/.changes/next-release/Bug Fix-fd4826b9-25e6-428e-ba73-c774e79dd2ca.json

@@ -0,0 +1,4 @@
+{
+	"type": "Bug Fix",
+	"description": "Amazon Q /dev: update diff window behavior after a change is accepted"
+}

packages/core/src/amazonq/commons/diff.ts

@@ -33,11 +33,3 @@ export function createAmazonQUri(path: string, tabId: string) {
     // TODO change the featureDevScheme to a more general amazon q scheme
     return vscode.Uri.from({ scheme: featureDevScheme, path, query: `tabID=${tabId}` })
 }
-
-export async function openFile(path: string) {
-    if (!(await fs.exists(path))) {
-        return
-    }
-    const fileUri = vscode.Uri.file(path)
-    await vscode.commands.executeCommand('vscode.diff', fileUri, fileUri)
-}

packages/core/src/amazonq/index.ts

@@ -27,14 +27,7 @@ export { amazonQHelpUrl } from '../shared/constants'
 export { listCodeWhispererCommandsWalkthrough } from '../codewhisperer/ui/statusBarMenu'
 export { focusAmazonQPanel, focusAmazonQPanelKeybinding } from '../codewhispererChat/commands/registerCommands'
 export { TryChatCodeLensProvider, tryChatCodeLensCommand } from '../codewhispererChat/editor/codelens'
-export {
-    createAmazonQUri,
-    openDiff,
-    openDeletedDiff,
-    getOriginalFileUri,
-    getFileDiffUris,
-    openFile,
-} from './commons/diff'
+export { createAmazonQUri, openDiff, openDeletedDiff, getOriginalFileUri, getFileDiffUris } from './commons/diff'
 export { CodeReference } from '../codewhispererChat/view/connector/connector'
 export { AuthMessageDataMap, AuthFollowUpType } from './auth/model'
 export { extractAuthFollowUp } from './util/authUtils'

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

@@ -43,7 +43,7 @@ import { openUrl } from '../../../shared/utilities/vsCodeUtils'
 import { getPathsFromZipFilePath } from '../../util/files'
 import { examples, messageWithConversationId } from '../../userFacingText'
 import { getWorkspaceFoldersByPrefixes } from '../../../shared/utilities/workspaceUtils'
-import { openDeletedDiff, openDiff, openFile } from '../../../amazonq/commons/diff'
+import { openDeletedDiff, openDiff } from '../../../amazonq/commons/diff'
 import { i18n } from '../../../shared/i18n-helper'
 import globals from '../../../shared/extensionGlobals'
 import { randomUUID } from '../../../shared'
@@ -750,7 +750,7 @@ export class FeatureDevController {
                 this.sendAcceptCodeTelemetry(session, 1)
                 await session.insertNewFiles([session.state.filePaths[filePathIndex]])
                 await session.insertCodeReferenceLogs(session.state.references ?? [])
-                await this.openFile(session.state.filePaths[filePathIndex])
+                await this.openFile(session.state.filePaths[filePathIndex], tabId)
             } else {
                 session.state.filePaths[filePathIndex].rejected = !session.state.filePaths[filePathIndex].rejected
             }
@@ -828,9 +828,10 @@ export class FeatureDevController {
         }
     }
 
-    private async openFile(filePath: NewFileInfo) {
-        const absolutePath = path.join(filePath.workspaceFolder.uri.fsPath, filePath.relativePath)
-        await openFile(absolutePath)
+    private async openFile(filePath: NewFileInfo, tabId: string) {
+        const leftPath = path.join(filePath.workspaceFolder.uri.fsPath, filePath.relativePath)
+        const rightPath = filePath.virtualMemoryUri.path
+        await openDiff(leftPath, rightPath, tabId)
     }
 
     private async stopResponse(message: any) {

packages/core/src/test/amazonq/common/diff.test.ts

@@ -12,14 +12,7 @@ import assert from 'assert'
 import * as path from 'path'
 import * as vscode from 'vscode'
 import sinon from 'sinon'
-import {
-    createAmazonQUri,
-    getFileDiffUris,
-    getOriginalFileUri,
-    openDeletedDiff,
-    openDiff,
-    openFile,
-} from '../../../amazonq'
+import { createAmazonQUri, getFileDiffUris, getOriginalFileUri, openDeletedDiff, openDiff } from '../../../amazonq'
 import { FileSystem } from '../../../shared/fs/fs'
 
 describe('diff', () => {
@@ -119,21 +112,4 @@ describe('diff', () => {
             assert.deepStrictEqual(right, rightExpected)
         })
     })
-
-    describe('openFile', () => {
-        it('file exists locally', async () => {
-            sandbox.stub(FileSystem.prototype, 'exists').resolves(true)
-            await openFile(filePath)
-
-            const expected = vscode.Uri.file(filePath)
-            assert.ok(executeCommandSpy.calledWith('vscode.diff', expected, expected))
-        })
-
-        it('file does not exists locally', async () => {
-            sandbox.stub(FileSystem.prototype, 'exists').resolves(false)
-            await openFile(filePath)
-
-            assert.ok(executeCommandSpy.notCalled)
-        })
-    })
 })