The flutter_test package is able to run Flutter apps 'headless', without requiring any embedder. It would be useful to me to be able to run a command line tool (i.e. not a test) in the same mode. Is this possible? I looked at the flutter_test package but nothing there seems to be the magic solution.
What I've tried:
Running a CLI tool that depends on Flutter with dart path/to/tool.dart. This throws Error: Not found: 'dart:ui'.
Running it with flutter run path/to/tool.dart. This will attempt to start the CLI tool as a regular Flutter app on a device (such as an Emulator, the desktop OS, or a web browser).
Running with flutter pub run path/to/tool.dart just generates a lot of errors, such as "Error: 'Paint' isn't a type". I tried all approaches suggested in this related SO Question, with the script living in various directories and using different invocations, but no luck.
Running the tool using flutter test path/to/tool.dart does work, and it runs the code in main() like one would expect. But I consider this a hacky workaround, since flutter test (unsurprisingly) expects a test, and exits with the error "No tests were found." And, semantically, it's just wrong. This is not a test. It's a tool.
If your code relies on package:flutter or dart:ui, you won't be able to run it outside of a Flutter engine instance (e.g., flutter_tester or a Flutter application) as dart:ui is a custom core library for Flutter that isn't part of Dart's core libraries. Short of hacking away at flutter_tester to remove the test runner related logic or creating your own custom embedder of the Flutter engine, you won't be able to run a Flutter project headless on the command line.
Ideally, you'd just refactor your tool to not depend on dart:ui at all, but given your background I'm guessing you're trying to do something non-standard that actually requires functionality from the Flutter framework... :-)
Related
Recently, I ran into an issue at work. To summarize it, I am currently working on writing test cases for an internal Flutter project. This had been working fine for a while, but after my summer vacation, it started breaking. It took me a while to figure out what roughly was going on, but I hen discovered that running integration tests generated a file named generated_main.dart under .dart_tool/flutter_build/. This was working just fine when using integration tests, however, it caused unit tests to fail due to not even loading.
I managed to identify the relevant line of code in the generated file as line eight: import 'file:///tmp/flutter_tools.WJSDQT/flutter_test_listener.YHXZLS/listener.dart' as entrypoint;. The capitalized strings of random characters are indeed random, apparently referring to a temporary path that only exists for the unit test's duration. Unit tests throw (even though not always reliably): .dart_tool/flutter_build/generated_main.dart:8:8: Error: Error when reading '/tmp/flutter_tools.WJSDQT/flutter_test_listener.YHXZLS/listener.dart': No such file or directory.
Surprisingly, there seem to be no issues when deleting the generated file. I have now added a print statement to the integration tests that tells whoever ran them that they need to delete the generated file. But this is obviously not a good solution long-term. Is there a way to disable this behavior so that testing does not become unnecessarily more complicated?
My environment is Ubuntu 20.04 LTS with Flutter 2.5.0-5.1.pre on channel beta, using Android Studio 2020.3.1. I am not currently able to test for this behavior on other platforms. The program needs to run on Linux. The test package version is 1.17.10, the newest one compatible with other dependencies.
Thank you in advance for your time.
I'd like to have the output of some git describe call available inside my flutter app. It's important that this is run automatically before builds triggered by i.e. flutter run or flutter build apk. If I have to remember running a command manually before rebuilding the app in my IDE I won't get an accurate version number in the app.
I looked at https://pub.dev/packages/build_runner but that seems to require to always invoke it manually.
I also looked at --dart-define but through this I can just pass values into dart code but I also need a way to automatically update that value.
I did get this to work through gradle... but that is only invoked for android builds. Adding it additionally to the cmake layer would work... that still leaves web and iOS builds without a solution.
Anyone got an idea what I might be missing?
(flutter can already generate code for translations dynamically via the generate: true flag but this doesn't seem to be exposed through any way to add custom generation commands there?)
Following these directions, like:
Install the Flutter and Dart plugins
Start VS Code.
Invoke View > Command Palette….
Type “install”, and select Extensions: Install Extensions.
Type “flutter” in the extensions search field, select Flutter in the list, and click Install. This also installs the required Dart plugin.
Validate your setup with the Flutter Doctor
Invoke View > Command Palette….
Type “doctor”, and select the Flutter: Run Flutter Doctor.
Review the output in the OUTPUT pane for any issues. Make sure to select Flutter from the dropdown in the different Output Options.
Step 3 of validate instructions results with OUTPUT:
I did install flutter, and flutter doctor in a new command shell gives result:
What am I missing here? I also try VSCode extension palette command Flutter: New Application Project and that also fails with:
Make sure that you have installed Git and that you can access it from the command line. Check your PATH. Flutter SDK directory should be present there.
If that does not work, you should try to reinstall the dart and flutter extension.
Next Step should be to reinstall flutter.
It occurred to me that my attempt to support multiple flutter versions might be going outside of the conventions supported by the Flutter extension for VSCode.
Here's what's up!... If you think you're smart like me and installed different versions of flutter in folders like c:\src\flutter\1.20.2 and c:\src\flutter\1.22.6, then you can forget it because the extension is smarter than us, and will ignore this regardless of our PATH assignment.
Copying contents of my flutter install from c:\src\flutter\1.22.6 to the parent folder c:\src\flutter resolved my issue. I need to review how to easily support different versions of flutter. Hmmm..
BTW... what I realized in retrospect is that the complaint about git is raised by the extension not finding the .git folder under the flutter folder (i.e. c:\src\flutter) that it presumed as the path to my flutter install. Well duh!! That's because I want flutter to be sourced at the versioned sub-folder (i.e. c:\src\flutter\1.22.6). Oh well.
Some scenarios I am left pondering:
How to correctly support multiple flutter installations while also benefiting from the extension (is there a way to configure this extension or my environment as a whole)?
Are my expectations to support multiple flutter installations unreasonable?
If my expectations are reasonable, and there are no known or documented way to support multiple flutter installations while also using this extension, then perhaps the extension has a bug?
So I just won a new laptop in a competition and now I am having some trouble migrating my flutter projects. I have set up the editor and migrated the important files in the code, i.e the lib, image, font, pubspec.yaml and web. But this app is now throwing the following error
Launching lib\main.dart on Chrome in debug mode...
Waiting for connection from debug service on Chrome...
ERROR - 2020-12-29 13:08:07.845202
GET /main_module.bootstrap.js
Error thrown by handler.
AbsoluteImportUriError: 'file:///C:/FlutterProjects/xspectre/lib/help/Auth.dart'
package:dwds/src/debugging/metadata/provider.dart 154:9 MetadataProvider._addMetadata
package:dwds/src/debugging/metadata/provider.dart 133:15 MetadataProvider._initialize.<fn>
I thought it may be a problem with my flutter but it runs the default flutter app without problem.
I also tried deleting the file but the problem just shifts to another file. I can safely say that this a is a problem with the help folder which provides me essential tools such as the auth service. What should I do? I will provide any code neccesary. You can find the entire code here
The Error:
The error is happening because when importing your new project, some imports in your .dart files are now using absolute paths instead of relative paths. In your case, this is happening at least in one .dart file that is calling your Auth.dart.
Sloution:
Step 1: Look at the top of all your .dart files, more precisely at every single import. You will have to change everything starting with:
import 'file:///C:/...
by
import 'package:... and add the name of your app
Step 2: Rerun your project and everything should work now
If still issues, then make sure you looked at all your files to ensure you did not miss other wrong import... also, you can run flutter clean then run a Pub Get
(thanks to melwinlobo18)
Please mark the answer if this was useful ;0)
I can't run all of my flutter apps, because in the console appears everytime this error message:
Downloading Gradle Wrapper... 1,2s
Launching lib\main.dart on SM G960F in debug mode...
Running Gradle task 'assembleDebug'...
Finished with error: Unable to locate gradlew script. Please check that C:\Users\...\android\gradlew.bat exists or that C:\Users\...\android can be read.
I try to fix this problem more than ten hours and don't find a solution.
I will advise you to check your pc properly for unwanted programs. Something is preventing your pc from running the Gradle. I had the same issue only to realize that antivirus was installed on my pc alongside a cd burner that I just installed. Check for any antivirus that might be preventing Gradle from running.
I also faced the same error initially. While creating a flutter application from scratch I just ran the default flutter application which is a counter app in a flutter. I faced the same issue at first. If you are in this same context as described earlier the following could be the solution
1.Java 8 is more suitable for the flutter/android development. The next versions of java have some exceptions. I used the Java 14 and stuck at this issue for some time
The next could be the JAVA_HOME path in your environment variables. If it is not provided the set the JAVA_HOME path.
Run flutter --doctor and check the requirements if satisfied like Android SDK is updated or not, upgrade flutter if required. In some cases having good Internet connection also plays a role in this issue some times.
These are the major points to be satisfied in order to get rid of this error. Mostly this could be the a solution or part of it.
The error suggests that something is preventing gradle to run properly on your machine. Check whether you have any unwanted programs or anti-virus on your machine running that might be preventing gradle to run. If so, remove or stop those programs / anti-virus and try again.
After that, delete the .gradle folder located here C:\Users\yourPcName\.gradle containing the unfinished file and try again . It will work now .
You can also manually download Gradle and map it in Android studio , Learn more with this article here .
Warning, the gradle versions change quickly, so make sure you manually
downloaded the exact version that flutter wanted to download and the
download failed. Download the gradle here and then replace it in the
gradle folder.
C:\Users\yourPcName\.gradle\wrapper\dists\gradle-x.x.x-all
If it still doesn't work,
Try to run flutter --doctor
From a console window that has the Flutter directory in the path (see above), run the following command to see if there are any platform dependencies you need to complete the setup:
C:\src\flutter> : flutter doctor
This command checks your environment and displays a report of the status of your Flutter installation. Check the output carefully for other software you might need to install or further tasks to perform (shown in bold text).
You can learn more here :
If flutter doctor itself doesn't work, then know that flutter is not installed on your machine (or you forgot to add it to the environment
variable).
I also faced this problem and I made something to run my app on android
tried to open anything on android files and android studio ask me if I want to open for editing android file in android studio then click on it and it will open android project then click run enter image description here