`enterText` to move the caret to the end (#79506)

packages/flutter/test/material/text_field_test.dart

@@ -848,18 +848,24 @@ void main() {
   );
 
   testWidgets('cursor layout has correct width', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController.fromValue(
+      const TextEditingValue(selection: TextSelection.collapsed(offset: 0)),
+    );
+    final FocusNode focusNode = FocusNode();
     EditableText.debugDeterministicCursor = true;
     await tester.pumpWidget(
         overlay(
-          child: const RepaintBoundary(
+          child: RepaintBoundary(
             child: TextField(
               cursorWidth: 15.0,
+              controller: controller,
+              focusNode: focusNode,
             ),
           ),
         )
     );
-    await tester.enterText(find.byType(TextField), ' ');
-    await skipPastScrollingAnimation(tester);
+    focusNode.requestFocus();
+    await tester.pump();
 
     await expectLater(
       find.byType(TextField),
@@ -869,19 +875,25 @@ void main() {
   });
 
   testWidgets('cursor layout has correct radius', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController.fromValue(
+      const TextEditingValue(selection: TextSelection.collapsed(offset: 0)),
+    );
+    final FocusNode focusNode = FocusNode();
     EditableText.debugDeterministicCursor = true;
     await tester.pumpWidget(
         overlay(
-          child: const RepaintBoundary(
+          child: RepaintBoundary(
             child: TextField(
               cursorWidth: 15.0,
-              cursorRadius: Radius.circular(3.0),
+              cursorRadius: const Radius.circular(3.0),
+              controller: controller,
+              focusNode: focusNode,
             ),
           ),
         )
     );
-    await tester.enterText(find.byType(TextField), ' ');
-    await skipPastScrollingAnimation(tester);
+    focusNode.requestFocus();
+    await tester.pump();
 
     await expectLater(
       find.byType(TextField),
@@ -891,19 +903,25 @@ void main() {
   });
 
   testWidgets('cursor layout has correct height', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController.fromValue(
+      const TextEditingValue(selection: TextSelection.collapsed(offset: 0)),
+    );
+    final FocusNode focusNode = FocusNode();
     EditableText.debugDeterministicCursor = true;
     await tester.pumpWidget(
         overlay(
-          child: const RepaintBoundary(
+          child: RepaintBoundary(
             child: TextField(
               cursorWidth: 15.0,
               cursorHeight: 30.0,
+              controller: controller,
+              focusNode: focusNode,
             ),
           ),
         )
     );
-    await tester.enterText(find.byType(TextField), ' ');
-    await skipPastScrollingAnimation(tester);
+    focusNode.requestFocus();
+    await tester.pump();
 
     await expectLater(
       find.byType(TextField),
@@ -1115,8 +1133,8 @@ void main() {
     await tester.tapAt(ePos);
     await tester.pump();
 
-    expect(controller.selection.baseOffset, -1);
-    expect(controller.selection.extentOffset, -1);
+    expect(controller.selection.baseOffset, testValue.length);
+    expect(controller.selection.isCollapsed, isTrue);
   });
 
   testWidgets('Can long press to select', (WidgetTester tester) async {
@@ -1584,8 +1602,7 @@ void main() {
     await tester.pump();
 
     expect(controller.selection.isCollapsed, true);
-    expect(controller.selection.baseOffset, -1);
-    expect(controller.selection.extentOffset, -1);
+    expect(controller.selection.baseOffset, testValue.length);
   });
 
   testWidgets('Can select text by dragging with a mouse', (WidgetTester tester) async {
@@ -5218,7 +5235,8 @@ void main() {
     const String testValue = 'x';
     await tester.enterText(find.byType(TextField), testValue);
     await skipPastScrollingAnimation(tester);
-    expect(controller.selection.baseOffset, -1);
+    expect(controller.selection.isCollapsed, true);
+    expect(controller.selection.baseOffset, testValue.length);
 
     // Tap the selection handle to bring up the "paste / select all" menu.
     await tester.tapAt(textOffsetToPosition(tester, 0));

packages/flutter_test/lib/src/test_text_input.dart

@@ -166,10 +166,14 @@ class TestTextInput {
   }
 
   /// Simulates the user typing the given text.
+  ///
+  /// Calling this method replaces the content of the connected input field with
+  /// `text`, and places the caret at the end of the text.
   void enterText(String text) {
     assert(isRegistered);
     updateEditingValue(TextEditingValue(
       text: text,
+      selection: TextSelection.collapsed(offset: text.length),
     ));
   }
 

packages/flutter_test/lib/src/widget_tester.dart

@@ -1040,13 +1040,16 @@ class WidgetTester extends WidgetController implements HitTestDispatcher, Ticker
     });
   }
 
-  /// Give the text input widget specified by [finder] the focus and
-  /// enter [text] as if it been provided by the onscreen keyboard.
+  /// Give the text input widget specified by [finder] the focus and replace its
+  /// content with [text], as if it had been provided by the onscreen keyboard.
   ///
   /// The widget specified by [finder] must be an [EditableText] or have
   /// an [EditableText] descendant. For example `find.byType(TextField)`
   /// or `find.byType(TextFormField)`, or `find.byType(EditableText)`.
   ///
+  /// When the returned future completes, the text input widget's text will be
+  /// exactly `text`, and the caret will be placed at the end of `text`.
+  ///
   /// To just give [finder] the focus without entering any text,
   /// see [showKeyboard].
   Future<void> enterText(Finder finder, String text) async {

packages/flutter_test/test/test_text_input_test.dart

@@ -7,6 +7,24 @@ import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
+  testWidgets('enterText works', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: Material(
+          child: TextField(),
+        ),
+      ),
+    );
+
+    final EditableTextState state = tester.state(find.byType(EditableText));
+    expect(state.textEditingValue.text, '');
+
+    await tester.enterText(find.byType(EditableText), 'let there be text');
+    expect(state.textEditingValue.text, 'let there be text');
+    expect(state.textEditingValue.selection.isCollapsed, isTrue);
+    expect(state.textEditingValue.selection.baseOffset, 17);
+  });
+
   testWidgets('receiveAction() forwards exception when exception occurs during action processing', (WidgetTester tester) async {
     // Setup a widget that can receive focus so that we can open the keyboard.
     const Widget widget = MaterialApp(