fix(amazonq): Correct indent when insertAtCursor (#5447)

Problem:
- When inserting code from Q chat, the indentation is wrong.

Solution:
- Pad recommendation with correct indentation

Note: This solution cannot solve cases when code suggestion contains a new line raw string in the string variable but it should be an improvement over existing experience.

Author: leigaol

packages/amazonq/.changes/next-release/Bug Fix-bc198b50-8d33-4a9a-900a-4a593e35d177.json

@@ -0,0 +1,4 @@
+{
+	"type": "Bug Fix",
+	"description": "Correct indentation when insert Q chat code at cursor position"
+}

packages/core/src/amazonq/commons/controllers/contentController.ts

@@ -3,20 +3,42 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import * as vscode from 'vscode'
 import { Position, TextEditor, window } from 'vscode'
 import { getLogger } from '../../../shared/logger'
 
 export class EditorContentController {
+    /* *
+     *  Insert the Amazon Q chat written code to the cursor position
+     *  Add current intentation to the next few lines of the recommendation
+     * @param text the raw text from Amazon Q chat
+     * @param trackCodeEdit callback to track user edits
+     */
     public insertTextAtCursorPosition(
         text: string,
         trackCodeEdit: (editor: TextEditor, cursorStart: Position) => void
     ) {
         const editor = window.activeTextEditor
         if (editor) {
             const cursorStart = editor.selection.active
+            const indentRange = new vscode.Range(new vscode.Position(cursorStart.line, 0), cursorStart)
+            // use the user editor intent if the position to the left of cursor is just space or tab
+            // otherwise indent with empty space equal to the intent at this position
+            let indent = editor.document.getText(indentRange)
+            if (indent.trim().length !== 0) {
+                indent = ' '.repeat(indent.length - indent.trimStart().length)
+            }
+            let textWithIndent = ''
+            text.split('\n').forEach((line, index) => {
+                if (index === 0) {
+                    textWithIndent += line
+                } else {
+                    textWithIndent += '\n' + indent + line
+                }
+            })
             editor
                 .edit((editBuilder) => {
-                    editBuilder.insert(cursorStart, text)
+                    editBuilder.insert(cursorStart, textWithIndent)
                 })
                 .then(
                     (appliedEdits) => {

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

@@ -0,0 +1,50 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import * as vscode from 'vscode'
+import assert from 'assert'
+import { EditorContentController } from '../../../amazonq/commons/controllers/contentController'
+import { openATextEditorWithText } from '../../testUtil'
+
+describe('contentController', () => {
+    let controller: EditorContentController
+
+    beforeEach(async () => {
+        controller = new EditorContentController()
+    })
+
+    describe('insertTextAtCursorPosition', () => {
+        it('insert code when left hand size has no non empty character', async () => {
+            const editor = await openATextEditorWithText('def hello_world():\n    ', 'test.py')
+            if (editor) {
+                const pos = new vscode.Position(1, 4)
+                editor.selection = new vscode.Selection(pos, pos)
+                controller.insertTextAtCursorPosition(
+                    'abc\n   def',
+                    (editor: vscode.TextEditor, cursorStart: vscode.Position) => {
+                        assert.equal(editor.document.getText(), 'def hello_world():\n    abc\n    def')
+                    }
+                )
+            } else {
+                assert.fail('Failed to open a text editor')
+            }
+        })
+
+        it('insert code when left hand size has non empty character', async () => {
+            const editor = await openATextEditorWithText('def hello_world():\n    ', 'test.py')
+            if (editor) {
+                const pos = new vscode.Position(0, 4)
+                editor.selection = new vscode.Selection(pos, pos)
+                controller.insertTextAtCursorPosition(
+                    'abc\n   def',
+                    (editor: vscode.TextEditor, cursorStart: vscode.Position) => {
+                        assert.equal(editor.document.getText(), 'def abc\n    defhello_world():\n')
+                    }
+                )
+            } else {
+                assert.fail('Failed to open a text editor')
+            }
+        })
+    })
+})