Bad state: Too many elements FLUTTER

Question

I am getting this error. I would like a hint or something to get rid of this error.

Unhandled exception:
DriverError: Error in Flutter application: Uncaught extension error while executing tap: Bad state: Too many elements
#0      Iterable.single (dart:core/iterable.dart:556:24)
#1      WidgetController._getElementPoint (package:flutter_test/src/controller.dart:646:47)
#2      WidgetController.getCenter (package:flutter_test/src/controller.dart:618:12)
#3      WidgetController.tap (package:flutter_test/src/controller.dart:256:18)
#4      FlutterDriverExtension._tap (package:flutter_driver/src/extension/extension.dart:388:19)
<asynchronous suspension>
#5      FlutterDriverExtension.call (package:flutter_driver/src/extension/extension.dart:216:53)
#6      BindingBase.registerServiceExtension.<anonymous closure> (package:flutter/src/foundation/binding.dart:528:32)
<asynchronous suspension>
#7      BindingBase.registerServiceExtension.<anonymous closure> (package:flutter/src/foundation/binding.dart)
#8      _runExtension (dart:developer-patch/developer.dart:86:23)

I have created custom widget

FrameInputField(
          key: ValueKey("login_email"),
          name: 'EMAIL',
          controller: _usernameController,
        ),

inside of this widget I have the following

class FrameInputField extends StatefulWidget {
  final TextEditingController controller;
  final String name;

  const FrameInputField(
      {@required this.controller,
      @required this.name,
      Key key}) : super(key:key);

  @override
  _FrameInputFieldState createState() => _FrameInputFieldState();
}
class _FrameInputFieldState extends State<FrameInputField> {
  bool _showPassword = false;
  bool lowercase = false;
  bool special = false;
  bool uppercase = false;
  bool eight = false;
  bool number = false;

 @override
  Widget build(BuildContext context) {
    return Container(
Focus(
            onFocusChange: (hasFocus) {
              if (!hasFocus)
                setState(() {
                  _showPassword = false;
                });
            },
            child: TextFormField(
              validator: (value) {
                if (widget.tries != null) {
                  return 'Incorrect password.';
                } else
                  return null;
              },
              key: widget.key,
              keyboardType: widget.numKeyboard ? TextInputType.number : null,
              controller: widget.controller,
              enabled: widget.enabled,
.
.
.
.

I need to find that particular TextFormField as mentioned above, but I get the mentioned error. Am I doing something wrong? The key I am using is unique and never been used in the whole code.

I get this error by doing the following:

final emailTextField = find.byValueKey("login_email");

and is followed by this method:

  Future<String> setEmail (String email) async {
    await _driver.tap(emailTextField);
    await _driver.enterText(email);
    assert(_driver.getText(passwordTextField).toString() == email);
  }

`

[√] Flutter (Channel stable, v1.17.4, on Microsoft Windows [Version 10.0.16299.1127], locale en-US)

[√] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[√] Android Studio (version 4.0)
[√] IntelliJ IDEA Community Edition (version 2018.2)
[!] Connected device
    ! No devices available

! Doctor found issues in 1 category.

Can you help me resolve this issue?

Thanks!

Answer 1

This problem is due to duplicate keys, in this case try to pass the key value to the correct widget and create the key for it.

Before:

MyCustonFormField(
  key: Key(valueKey),
  ...
)

...

class MyCustonFormField{
  final Key key;

  ...
  Widget build(BuildContext context) {
  return TextField(
     key: this.key,
  )
}

After:

MyCustonFormField(
  key: valueKey,
  ...
)

...

class MyCustonFormField{
  dynamic valueKey;

  ...
  Widget build(BuildContext context) {
  return TextField(
     key: Key(this.valueKey),
  )
}