Why does this Flutter test fails on CodeMagic?

Question

When I try to test the build on Codemagic, the test fails. I tried to change widget_test.dart code, Still the problem remains unsolved. How to resolve this issue?

This is the error thrown by codemagic.

== QA ==

== flutter test --machine ==
{"protocolVersion":"0.1.1","runnerVersion":null,"pid":949,"type":"start","time":0}
{"suite":{"id":0,"platform":"vm","path":"/Users/builder/clone/test/widget_test.dart"},"type":"suite","time":1}
{"test":{"id":1,"name":"loading /Users/builder/clone/test/widget_test.dart","suiteID":0,"groupIDs":[],"metadata":{"skip":false,"skipReason":null},"line":null,"column":null,"url":null},"type":"testStart","time":3}
{"count":1,"type":"allSuites","time":7}
{"testID":1,"result":"success","skipped":false,"hidden":true,"type":"testDone","time":15317}
{"group":{"id":2,"suiteID":0,"parentID":null,"name":null,"metadata":{"skip":false,"skipReason":null},"testCount":1,"line":null,"column":null,"url":null},"type":"group","time":15341}
{"test":{"id":3,"name":"Counter increments smoke test","suiteID":0,"groupIDs":[2],"metadata":{"skip":false,"skipReason":null},"line":107,"column":3,"url":"package:flutter_test/src/widget_tester.dart","root_line":14,"root_column":3,"root_url":"file:///Users/builder/clone/test/widget_test.dart"},"type":"testStart","time":15343}
{"testID":3,"messageType":"print","message":"══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════\nThe following TestFailure object was thrown running a test:\n  Expected: exactly one matching node in the widget tree\n  Actual: ?:<zero widgets with text \"0\" (ignoring offstage widgets)>\n   Which: means none were found but one was expected\n\nWhen the exception was thrown, this was the stack:\n#4      main.<anonymous closure> (file:///Users/builder/clone/test/widget_test.dart:19:5)\n<asynchronous suspension>\n#5      testWidgets.<anonymous closure>.<anonymous closure> (package:flutter_test/src/widget_tester.dart:118:25)\n<asynchronous suspension>\n#6      TestWidgetsFlutterBinding._runTestBody (package:flutter_test/src/binding.dart:630:19)\n<asynchronous suspension>\n#9      TestWidgetsFlutterBinding._runTest (package:flutter_test/src/binding.dart:613:14)\n#10     AutomatedTestWidgetsFlutterBinding.runTest.<anonymous closure> (package:flutter_test/src/binding.dart:1010:24)\n#16     AutomatedTestWidgetsFlutterBinding.runTest (package:flutter_test/src/binding.dart:1007:15)\n#17     testWidgets.<anonymous closure> (package:flutter_test/src/widget_tester.dart:116:22)\n#18     Declarer.test.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test_api/src/backend/declarer.dart:168:27)\n<asynchronous suspension>\n#19     Invoker.waitForOutstandingCallbacks.<anonymous closure> (package:test_api/src/backend/invoker.dart:250:15)\n<asynchronous suspension>\n#24     Invoker.waitForOutstandingCallbacks (package:test_api/src/backend/invoker.dart:247:5)\n#25     Declarer.test.<anonymous closure>.<anonymous closure> (package:test_api/src/backend/declarer.dart:166:33)\n#30     Declarer.test.<anonymous closure> (package:test_api/src/backend/declarer.dart:165:13)\n<asynchronous suspension>\n#31     Invoker._onRun.<anonymous closure>.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:test_api/src/backend/invoker.dart:400:25)\n<asynchronous suspension>\n#45     _Timer._runTimers (dart:isolate-patch/timer_impl.dart:382:19)\n#46     _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:416:5)\n#47     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)\n(elided 28 frames from class _FakeAsync, package dart:async, package dart:async-patch, and package stack_trace)\n\nThis was caught by the test expectation on the following line:\n  file:///Users/builder/clone/test/widget_test.dart line 19\nThe test description was:\n  Counter increments smoke test\n════════════════════════════════════════════════════════════════════════════════════════════════════","type":"print","time":17092}
{"testID":3,"error":"Test failed. See exception logs above.\nThe test description was: Counter increments smoke test","stackTrace":"","isFailure":false,"type":"error","time":17119}
{"testID":3,"result":"error","skipped":false,"hidden":false,"type":"testDone","time":17134}
{"success":false,"type":"done","time":17231}


QA failed :|
Flutter test run failed.

== QA failed, ending build ==


Build failed :|
Test run failed: Flutter test run failed.

My Widget_test file code is

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

import 'package:top100/main.dart';

void main() {
  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
    // Build our app and trigger a frame.
    await tester.pumpWidget(MyApp());

    // Verify that our counter starts at 0.
    expect(find.text('0'), findsOneWidget);
    expect(find.text('1'), findsNothing);

    // Tap the '+' icon and trigger a frame.
    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();

    // Verify that our counter has incremented.
    expect(find.text('0'), findsNothing);
    expect(find.text('1'), findsOneWidget);
  });
}

Answer 1

The widget_test.dart file is created with the default project in Flutter, which has two text fields and an Icon which can be tapped. Since you modified the app UI, now you may have different elements showing and the test fails since it is expecting the template project elements which now you don't have. You can comment the testWidgets method for a quick fix:

// This is a basic Flutter widget test.
//
// To perform an interaction with a widget in your test, use the WidgetTester
// utility that Flutter provides. For example, you can send tap and scroll
// gestures. You can also use WidgetTester to find child widgets in the widget
// tree, read text, and verify that the values of widget properties are correct.

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

import 'package:fin_app_flutter/main.dart';

void main() {
  /*
  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
    // Build our app and trigger a frame.
    await tester.pumpWidget(MyApp());

    // Verify that our counter starts at 0.
    expect(find.text('0'), findsOneWidget);
    expect(find.text('1'), findsNothing);

    // Tap the '+' icon and trigger a frame.
    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();

    // Verify that our counter has incremented.
    expect(find.text('0'), findsNothing);
    expect(find.text('1'), findsOneWidget);
  });
  */
}

Remember to commit and sync your branch on Codemagic.