flutter test type 'Null' is not a subtype of type 'bool' in type cast package:test_api RemoteListener.start.<fn>.<fn>

[felangel]

Steps to Reproduce

package:test v1.18.0 throws when running flutter test:

import 'package:test/test.dart';

void main() {
  test('...', () {
    expect(true, isTrue);
  });
}

• Using dart test works
• Using package:test 1.17.12 with flutter test also works

Expected results: I would expect the test to pass

Actual results:

$ flutter test   
00:00 +0 -1: loading my_test.dart [E]   
  Failed to load "my_test.dart": type 'Null' is not a subtype of type 'bool' in type cast
  package:test_api  RemoteListener.start.<fn>.<fn>
  
00:00 +0 -1: Some tests failed.

Logs

[✓] Flutter (Channel beta, 2.6.0-5.2.pre, on macOS 11.4 20F71 darwin-x64, locale
    en-US)
    • Flutter version 2.6.0-5.2.pre at /Users/felix/fvm/versions/beta
    • Upstream repository git@github.com:flutter/flutter.git
    • Framework revision 400608f101 (2 weeks ago), 2021-09-15 15:50:26 -0700
    • Engine revision 1d521d89d8
    • Dart version 2.15.0 (build 2.15.0-82.2.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/felix/Library/Android/sdk
    • Platform android-30, build-tools 29.0.2
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.5)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.10.1

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] IntelliJ IDEA Community Edition (version 2021.2)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] VS Code (version 1.60.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.25.0

[✓] VS Code (version 1.61.0-insider)
    • VS Code at /Applications/Visual Studio Code - Insiders.app/Contents
    • Flutter extension version 3.26.0

[✓] Connected device (2 available)
    • macOS (desktop) • macos  • darwin-x64     • macOS 11.4 20F71 darwin-x64
    • Chrome (web)    • chrome • web-javascript • Google Chrome 94.0.4606.61
    ! Error: Felix’s iPhone is not connected. Xcode will continue when Felix’s
      iPhone is connected. (code -13)

[maheshj01]

HI @felangel. Thanks for filing the issue, I can confirm the test passes dart test and fluter test with test: ^1.17.12 but I could not verify with test: ^1.18.0 there seems to be dependency conflict on any channel (beta, master, stable) are you overriding the dependencies?

Because no versions of test match >1.18.0 <2.0.0 and test 1.18.0 depends on test_api 0.4.4, test ^1.18.0 requires test_api 0.4.4.
And because every version of flutter_test from sdk depends on test_api 0.4.3, test ^1.18.0 is incompatible with flutter_test from sdk.
So, because sample depends on both flutter_test any from sdk and test ^1.18.0, version solving failed.
pub get failed (1; So, because sample depends on both flutter_test any from sdk and test ^1.18.0, version solving failed.)
exit code 1

flutter doctor -v

[✓] Flutter (Channel beta, 2.6.0-5.2.pre, on macOS 11.6 20G165 darwin-arm, locale en-GB)
    • Flutter version 2.6.0-5.2.pre at /Users/mahesh/Documents/flutter_beta
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 400608f101 (2 weeks ago), 2021-09-15 15:50:26 -0700
    • Engine revision 1d521d89d8
    • Dart version 2.15.0 (build 2.15.0-82.2.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/mahesh/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • ANDROID_HOME = /Users/mahesh/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6916264)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.10.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6916264)

[✓] IntelliJ IDEA Community Edition (version 2021.2.1)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin version 60.1.4
    • Dart plugin version 212.5080.8

[✓] VS Code (version 1.59.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.26.0

[✓] Connected device (3 available)
    • iPhone 11 Pro (mobile) • 3209EA5A-2ABF-46BE-8C94-83AAF6EF59FB • ios            • com.apple.CoreSimulator.SimRuntime.iOS-13-1 (simulator)
    • macOS (desktop)        • macos                                • darwin-arm64   • macOS 11.6 20G165 darwin-arm
    • Chrome (web)           • chrome                               • web-javascript • Google Chrome 94.0.4606.71

• No issues found!

[✓] Flutter (Channel master, 2.6.0-12.0.pre.165, on macOS 11.6 20G165 darwin-arm, locale en-GB)
    • Flutter version 2.6.0-12.0.pre.165 at /Users/mahesh/Documents/flutter_master
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision a20743ddfe (7 hours ago), 2021-09-30 23:43:02 -0400
    • Engine revision 8ec71b64f6
    • Dart version 2.15.0 (build 2.15.0-167.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/mahesh/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • ANDROID_HOME = /Users/mahesh/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6916264)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.10.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6916264)

[✓] IntelliJ IDEA Community Edition (version 2021.2.1)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin version 60.1.4
    • Dart plugin version 212.5080.8

[✓] VS Code (version 1.59.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.26.0

[✓] Connected device (3 available)
    • iPhone 11 Pro (mobile) • 3209EA5A-2ABF-46BE-8C94-83AAF6EF59FB • ios            • com.apple.CoreSimulator.SimRuntime.iOS-13-1 (simulator)
    • macOS (desktop)        • macos                                • darwin-arm64   • macOS 11.6 20G165 darwin-arm
    • Chrome (web)           • chrome                               • web-javascript • Google Chrome 94.0.4606.71

• No issues found!

[xsahil03x]

Hey @maheshmnj,

The issue is not in the flutter_test package but in the direct dependency test_api. It started from v0.4.4 and most probably related to the latest config field allow_duplicate_test_names. Which due to some reason seems to be null in this part of code and so the exception.

type 'Null' is not a subtype of type 'bool' in type cast
package:test_api  RemoteListener.start.<fn>.<fn>

Thanks.

[felangel]

@maheshmnj using the following pubspec.yaml:

name: example
description: An example
version: 1.0.0+1
publish_to: none

environment:
  sdk: ">=2.13.0 <3.0.0"

dev_dependencies:
  test: ^1.18.0

Running flutter packages get generates the following lock file:

pubspec.lock

# Generated by pub
# See https://dart.dev/tools/pub/glossary#lockfile
packages:
  _fe_analyzer_shared:
    dependency: transitive
    description:
      name: _fe_analyzer_shared
      url: "https://pub.dartlang.org"
    source: hosted
    version: "26.0.0"
  analyzer:
    dependency: transitive
    description:
      name: analyzer
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.3.0"
  args:
    dependency: transitive
    description:
      name: args
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.3.0"
  async:
    dependency: transitive
    description:
      name: async
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.8.2"
  boolean_selector:
    dependency: transitive
    description:
      name: boolean_selector
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.0"
  charcode:
    dependency: transitive
    description:
      name: charcode
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.3.1"
  cli_util:
    dependency: transitive
    description:
      name: cli_util
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.3.4"
  collection:
    dependency: transitive
    description:
      name: collection
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.15.0"
  convert:
    dependency: transitive
    description:
      name: convert
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.0.1"
  coverage:
    dependency: transitive
    description:
      name: coverage
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.3"
  crypto:
    dependency: transitive
    description:
      name: crypto
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.0.1"
  file:
    dependency: transitive
    description:
      name: file
      url: "https://pub.dartlang.org"
    source: hosted
    version: "6.1.2"
  frontend_server_client:
    dependency: transitive
    description:
      name: frontend_server_client
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.2"
  glob:
    dependency: transitive
    description:
      name: glob
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.0.2"
  http_multi_server:
    dependency: transitive
    description:
      name: http_multi_server
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.0.1"
  http_parser:
    dependency: transitive
    description:
      name: http_parser
      url: "https://pub.dartlang.org"
    source: hosted
    version: "4.0.0"
  io:
    dependency: transitive
    description:
      name: io
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.3"
  js:
    dependency: transitive
    description:
      name: js
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.6.3"
  logging:
    dependency: transitive
    description:
      name: logging
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.2"
  matcher:
    dependency: transitive
    description:
      name: matcher
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.12.11"
  meta:
    dependency: transitive
    description:
      name: meta
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.7.0"
  mime:
    dependency: transitive
    description:
      name: mime
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.0"
  node_preamble:
    dependency: transitive
    description:
      name: node_preamble
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.0.1"
  package_config:
    dependency: transitive
    description:
      name: package_config
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.0.2"
  path:
    dependency: transitive
    description:
      name: path
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.8.0"
  pedantic:
    dependency: transitive
    description:
      name: pedantic
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.11.1"
  pool:
    dependency: transitive
    description:
      name: pool
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.5.0"
  pub_semver:
    dependency: transitive
    description:
      name: pub_semver
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.0"
  shelf:
    dependency: transitive
    description:
      name: shelf
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.2.0"
  shelf_packages_handler:
    dependency: transitive
    description:
      name: shelf_packages_handler
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.0.0"
  shelf_static:
    dependency: transitive
    description:
      name: shelf_static
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.1.0"
  shelf_web_socket:
    dependency: transitive
    description:
      name: shelf_web_socket
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.1"
  source_map_stack_trace:
    dependency: transitive
    description:
      name: source_map_stack_trace
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.0"
  source_maps:
    dependency: transitive
    description:
      name: source_maps
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.10.10"
  source_span:
    dependency: transitive
    description:
      name: source_span
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.8.1"
  stack_trace:
    dependency: transitive
    description:
      name: stack_trace
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.10.0"
  stream_channel:
    dependency: transitive
    description:
      name: stream_channel
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.0"
  string_scanner:
    dependency: transitive
    description:
      name: string_scanner
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.1.0"
  term_glyph:
    dependency: transitive
    description:
      name: term_glyph
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.2.0"
  test:
    dependency: "direct dev"
    description:
      name: test
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.18.0"
  test_api:
    dependency: transitive
    description:
      name: test_api
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.4.4"
  test_core:
    dependency: transitive
    description:
      name: test_core
      url: "https://pub.dartlang.org"
    source: hosted
    version: "0.4.3"
  typed_data:
    dependency: transitive
    description:
      name: typed_data
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.3.0"
  vm_service:
    dependency: transitive
    description:
      name: vm_service
      url: "https://pub.dartlang.org"
    source: hosted
    version: "7.3.0"
  watcher:
    dependency: transitive
    description:
      name: watcher
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.1"
  web_socket_channel:
    dependency: transitive
    description:
      name: web_socket_channel
      url: "https://pub.dartlang.org"
    source: hosted
    version: "2.1.0"
  webkit_inspection_protocol:
    dependency: transitive
    description:
      name: webkit_inspection_protocol
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.0.0"
  yaml:
    dependency: transitive
    description:
      name: yaml
      url: "https://pub.dartlang.org"
    source: hosted
    version: "3.1.0"
sdks:
  dart: ">=2.14.0 <3.0.0"

As @xsahil03x mentioned, test_api version: "0.4.4" is used which appears to be the issue.

[jakemac53]

We did release a version of test_api to support this for now (via dart-lang/test#1592).

The real solution here is that all users using the flutter test command should have a dependency on the flutter_test package. That ensures they will get compatible versions.

The flutter test command itself should check for this dependency (similar to how dart test checks for a test package dependency).

[maheshj01]

so as mentioned by @jakemac53, in order to use flutter test, you will need to depend on flutter_test, but it is not compatible as of today with test: ^1.18.0, so I believe @felangel, you will need to depend on test_api until the compatibility issue gets resolved. I can confirm flutter test works with test_api: 0.4.5.

[jakemac53]

Instead of depending on test_api you should loosen your test constraint to something like ^1.17.0 (although honestly probably just ^1.0.0 is fine for most people).

[danagbemava-nc]

Without additional information, we are unfortunately not sure how to resolve this issue.
We are therefore reluctantly going to close this bug for now.
Please don't hesitate to comment on the bug if you have any more information for us; we will reopen it right away!
Thanks for your contribution.

Could everyone who still has this problem please file a new issue with the exact description of what happens, logs, and the output of flutter doctor -v.
All system setups can be slightly different, so it's always better to open new issues and reference related issues.