apidash/test/widgets/error_message_test.dart

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:apidash/widgets/error_message.dart';
import 'package:apidash/consts.dart';

void main() {
  String errorMessage =
      'This is an error message generated by the application ';
  testWidgets('Testing when Error Message is sent', (tester) async {
    await tester.pumpWidget(
      MaterialApp(
        title: 'Error Message',
        home: Scaffold(
          body: ErrorMessage(message: errorMessage),
        ),
      ),
    );

    expect(find.byIcon(Icons.warning_rounded), findsOneWidget);
    expect(find.byType(Center), findsNWidgets(3));
    expect(find.byIcon(Icons.arrow_outward_rounded), findsOneWidget);
    expect(find.byType(SelectableText), findsOneWidget);
    expect(find.text(errorMessage), findsOneWidget);
    expect(find.text('Raise Issue'), findsOneWidget);
    expect(
        find.text('An error occurred. $kUnexpectedRaiseIssue'), findsNothing);
    final dynamic filledButtonWithIconWidget = tester.widget(
        find.byWidgetPredicate((Widget widget) =>
            '${widget.runtimeType}' == '_FilledButtonWithIcon'));
    expect(find.byType(filledButtonWithIconWidget.runtimeType), findsOneWidget);
    await tester.tap(find.byType(filledButtonWithIconWidget.runtimeType));
  });

  testWidgets('Testing when no error message is sent', (tester) async {
    await tester.pumpWidget(
      const MaterialApp(
        title: 'Error Message',
        home: Scaffold(
          body: ErrorMessage(message: null),
        ),
      ),
    );

    expect(find.byIcon(Icons.warning_rounded), findsOneWidget);
    expect(find.byType(Center), findsNWidgets(3));
    expect(find.byIcon(Icons.arrow_outward_rounded), findsOneWidget);
    expect(find.byType(SelectableText), findsOneWidget);
    expect(find.text('Raise Issue'), findsOneWidget);
    expect(find.text(errorMessage), findsNothing);
    expect(
        find.text('An error occurred. $kUnexpectedRaiseIssue'), findsOneWidget);
    final dynamic filledButtonWithIconWidget = tester.widget(
        find.byWidgetPredicate((Widget widget) =>
            '${widget.runtimeType}' == '_FilledButtonWithIcon'));
    expect(find.byType(filledButtonWithIconWidget.runtimeType), findsOneWidget);
    await tester.tap(find.byType(filledButtonWithIconWidget.runtimeType));
  });
}