feat(lsp): add handler for openFileDiff notification

packages/amazonq/src/lsp/chat/messages.ts

@@ -39,15 +39,25 @@ import {
     ShowDocumentRequest,
     contextCommandsNotificationType,
     ContextCommandParams,
+    openFileDiffNotificationType,
+    OpenFileDiffParams,
 } from '@aws/language-server-runtimes/protocol'
 import { v4 as uuidv4 } from 'uuid'
 import * as vscode from 'vscode'
 import { Disposable, LanguageClient, Position, TextDocumentIdentifier } from 'vscode-languageclient'
 import * as jose from 'jose'
 import { AmazonQChatViewProvider } from './webviewProvider'
 import { AuthUtil } from 'aws-core-vscode/codewhisperer'
-import { AmazonQPromptSettings, messages } from 'aws-core-vscode/shared'
-import { DefaultAmazonQAppInitContext, messageDispatcher } from 'aws-core-vscode/amazonq'
+import {
+    amazonQDiffScheme,
+    AmazonQPromptSettings,
+    messages,
+    textDocumentUtil,
+    amazonQTabSuffix,
+    disposeOnEditorClose,
+} from 'aws-core-vscode/shared'
+import { ContentProvider, DefaultAmazonQAppInitContext, messageDispatcher } from 'aws-core-vscode/amazonq'
+import path from 'path'
 
 export function registerLanguageServerEventListener(languageClient: LanguageClient, provider: AmazonQChatViewProvider) {
     languageClient.info(
@@ -353,6 +363,24 @@ export function registerMessageListeners(
             params: params,
         })
     })
+
+    languageClient.onNotification(openFileDiffNotificationType.method, async (params: OpenFileDiffParams) => {
+        const uri = vscode.Uri.parse(params.originalFileUri)
+        const tempFileUri = await textDocumentUtil.createTempFileForDiffWithContent(
+            uri,
+            params.fileContent ?? '',
+            amazonQDiffScheme
+        )
+        const contentProvider = new ContentProvider(tempFileUri)
+        const disposable = vscode.workspace.registerTextDocumentContentProvider(amazonQDiffScheme, contentProvider)
+        await vscode.commands.executeCommand(
+            'vscode.diff',
+            uri,
+            tempFileUri,
+            `${path.basename(params.originalFileUri)} ${amazonQTabSuffix}`
+        )
+        disposeOnEditorClose(uri, disposable)
+    })
 }
 
 function isServerEvent(command: string) {

packages/core/src/amazonq/index.ts

@@ -47,6 +47,7 @@ export * as authConnection from '../auth/connection'
 export * as featureConfig from './webview/generators/featureConfig'
 export * as messageDispatcher from './webview/messages/messageDispatcher'
 import { FeatureContext } from '../shared/featureConfig'
+export { ContentProvider } from './commons/controllers/contentController'
 
 /**
  * main from createMynahUI is a purely browser dependency. Due to this

packages/core/src/shared/index.ts

@@ -56,7 +56,7 @@ export * as funcUtil from './utilities/functionUtils'
 export { fs } from './fs/fs'
 export * from './handleUninstall'
 export { CrashMonitoring } from './crashMonitoring'
-export { amazonQDiffScheme } from './constants'
+export { amazonQDiffScheme, amazonQTabSuffix } from './constants'
 export * from './featureConfig'
 export { i18n } from './i18n-helper'
 export * from './icons'
@@ -74,3 +74,4 @@ export * as BaseLspInstaller from './lsp/baseLspInstaller'
 export * as collectionUtil from './utilities/collectionUtils'
 export * from './datetime'
 export * from './performance/marks'
+export { disposeOnEditorClose } from './utilities/editorUtilities'

packages/core/src/shared/utilities/textDocumentUtilities.ts

@@ -119,20 +119,17 @@ export async function applyChanges(doc: vscode.TextDocument, range: vscode.Range
 }
 
 /**
- * Creates a temporary file for diff comparison by cloning the original file
- * and applying the proposed changes within the selected range.
+ * Creates a temporary file for diff comparison by cloning the original file.
+ * This is the base implementation used by other diff-related functions.
  *
  * @param {vscode.Uri} originalFileUri - The URI of the original file.
- * @param {any} message - The message object containing the proposed code changes.
- * @param {vscode.Selection} selection - The selection range in the document where the changes are applied.
- * @returns {Promise<vscode.Uri>} - A promise that resolves to the URI of the temporary file.
+ * @param {string} scheme - The URI scheme to use for the temporary file.
+ * @returns {Promise<{tempFileUri: vscode.Uri, doc: vscode.TextDocument}>} - A promise that resolves to the URI of the temporary file and the document.
  */
-export async function createTempFileForDiff(
+async function createTempFileForDiffBase(
     originalFileUri: vscode.Uri,
-    message: any,
-    selection: vscode.Selection,
     scheme: string
-): Promise<vscode.Uri> {
+): Promise<{ tempFileUri: vscode.Uri; doc: vscode.TextDocument }> {
     const errorCode = 'createTempFile'
     const id = Date.now()
     const languageId = (await vscode.workspace.openTextDocument(originalFileUri)).languageId
@@ -152,7 +149,7 @@ export async function createTempFileForDiff(
         throw ToolkitError.chain(error, 'Failed to write to temp file', { code: errorCode })
     }
 
-    // Apply the proposed changes to the temp file
+    // Open the temp file as a document
     const doc = await vscode.workspace.openTextDocument(tempFileUri.path)
     const languageIdStatus = await vscode.languages.setTextDocumentLanguage(doc, languageId)
     if (languageIdStatus) {
@@ -161,13 +158,60 @@ export async function createTempFileForDiff(
         getLogger().error('Diff: Unable to set languageId for %s to: %s', tempFileUri.fsPath, languageId)
     }
 
+    return { tempFileUri, doc }
+}
+
+/**
+ * Creates a temporary file for diff comparison by cloning the original file
+ * and applying the proposed changes within the selected range.
+ *
+ * @param {vscode.Uri} originalFileUri - The URI of the original file.
+ * @param {any} message - The message object containing the proposed code changes.
+ * @param {vscode.Selection} selection - The selection range in the document where the changes are applied.
+ * @param {string} scheme - The URI scheme to use for the temporary file.
+ * @returns {Promise<vscode.Uri>} - A promise that resolves to the URI of the temporary file.
+ */
+export async function createTempFileForDiff(
+    originalFileUri: vscode.Uri,
+    message: any,
+    selection: vscode.Selection,
+    scheme: string
+): Promise<vscode.Uri> {
+    const { tempFileUri, doc } = await createTempFileForDiffBase(originalFileUri, scheme)
+
     const code = getIndentedCode(message, doc, selection)
     const range = getSelectionFromRange(doc, selection)
 
     await applyChanges(doc, range, code)
     return tempFileUri
 }
 
+/**
+ * Creates a temporary file for diff comparison by cloning the original file
+ * and replacing the entire content with the provided content.
+ *
+ * @param {vscode.Uri} originalFileUri - The URI of the original file.
+ * @param {string} content - The content to replace the entire document with.
+ * @param {string} scheme - The URI scheme to use for the temporary file.
+ * @returns {Promise<vscode.Uri>} - A promise that resolves to the URI of the temporary file.
+ */
+export async function createTempFileForDiffWithContent(
+    originalFileUri: vscode.Uri,
+    content: string,
+    scheme: string
+): Promise<vscode.Uri> {
+    const { tempFileUri, doc } = await createTempFileForDiffBase(originalFileUri, scheme)
+
+    // Create a range that covers the entire document
+    const entireDocumentRange = new vscode.Range(
+        new vscode.Position(0, 0),
+        new vscode.Position(doc.lineCount - 1, doc.lineAt(doc.lineCount - 1).text.length)
+    )
+
+    await applyChanges(doc, entireDocumentRange, content)
+    return tempFileUri
+}
+
 /**
  * Indents the given code based on the current document's indentation at the selection start.
  *