I have made a java function genImage(List<String lines) which is located in class vis. I am trying to import it into my rascal code, but it won't work. This is the last of my efforts to import it:
#javaClass{visualization.vis}
java void genImage(list[str] lines);
The error I get:
Cannot link method visualization.vis because: visualization.vis.(io.usethesource.vallang.IValueFactory)
Advice: |http://tutor.rascal-mpl.org/Errors/Static/JavaMethodLink/JavaMethodLink.html%7C
The #javaClass tag must point to a fully qualified classname, including the package and the class. It seems it's the class you are missing, right?
I have an app, it is very simple and have just one widget. It is working fine, however when I run integration test by calling:
$ flutter drive --target=test_driver/app.dart
I get the following error:
file:///Users/myuser/flutter/packages/flutter_test/lib/src/accessibility.dart:8:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui;
^
file:///Users/myuser/flutter/packages/flutter_test/lib/src/binding.dart:8:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui;
^
file:///Users/myuser/flutter/packages/flutter_test/lib/src/matchers.dart:8:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui;
^
file:///Users/myuser/flutter/packages/flutter_test/lib/src/matchers.dart:9:8: Error: Not found: 'dart:ui'
import 'dart:ui';
^
file:///Users/myuser/flutter/packages/flutter_test/lib/src/test_pointer.dart:12:1: Error: Not found: 'dart:ui'
export 'dart:ui' show Offset;
^
file:///Users/myuser/flutter/packages/flutter/lib/src/rendering/binding.dart:8:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui show window;
^
file:///Users/myuser/flutter/packages/flutter/lib/src/rendering/box.dart:6:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui show lerpDouble;
^
file:///Users/myuser/flutter/packages/flutter/lib/src/rendering/debug_overflow_indicator.dart:6:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui;
^
file:///Users/myuser/flutter/packages/flutter/lib/src/rendering/editable.dart:8:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui show TextBox;
^
file:///Users/myuser/flutter/packages/flutter/lib/src/rendering/error.dart:5:8: Error: Not found: 'dart:ui'
import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphConstraints, ParagraphStyle, TextStyle;
^
Stopping application instance.
Driver tests failed: 254
Note that when I run the app from Android Studio, it runs successfully. But when I run from terminal using the command quoted above, the app shows a white screen and it doesn't move from there until I get the error on my terminal.
Assuming it's a path issue, like test_driver not finding flutter packages like dart:ui, how can I make sure test_driver knows where dart:ui is ?
Make sure that the import is set to this:
import 'package:test/test.dart';
instead of this:
import 'package:flutter_test/flutter_test.dart';
The integration tests can have no imports to your main App code or other flutter code that runs in the App - otherwise they will fail with your seen error.
Have a read of https://flutter.io/cookbook/testing/integration-test-introduction/ as this gives an example of integration tests with an app starting point that allows you to run setup code before your actual driver tests run if this is what you are looking to do. Otherwise don't use key values that use constants from your main code (as mentioned here http://cogitas.net/write-integration-test-flutter/).
This is old post, but I found another possible reason why test gave me this error:
When I was creating new Bloc class I created constructor with #required annotation and when I used Option+Enter for importing appropriate library, Android Studio imported 'package:flutter/cupertino.dart' library instead of 'package:meta/meta.dart' and that is the reason my unit test didn't start in the first place.
After importing correct library, all tests have passed!
Happy testing your code! :D
Here is the solution for adding these test cases:
In Android studio in the run dropdown you
select Edit Configurations
Press the + button and select Flutter test
Make sure the Test scope is All in file and point it at your test file.
You can now run the individual test file and also debug it in android studio by selecting this configuration in the run drop-down.
Remove all imports to package:flutter/... from the test driver's code, like:
import 'package:flutter/widgets.dart';
I was getting these erros because I was trying to import a widget on a test_driver file. I also got the same error if I try to use find.byWidget.
I was trying to import a widget or use find.byWidget because I wanted to check the existence of a widget on a screen.
These erros are pretty much similar to
The built-in library 'dart:ui' is not available on the stand-alone VM.
Then, in order to check the existence of a widget on screen in a test_driver file, I had to use find.byKeyValue. For example, given the following dummy widget, defined in a file within my app:
class MyDummyWidget extends StatelessWidget {
MyDummyWidget(): super(key: new Key('MyDummyWidget'));
#override
Widget build(BuildContext context) {
return Center();
}
}
To check if it is being displayed on screen, I define the following test within the test_driver:
void main() {
group('My tests', () {
FlutterDriver driver;
SerializableFinder myDummyWidget = find.byValueKey('MyDummyWidget');
setUpAll(() async {
driver = await FlutterDriver.connect();
});
tearDownAll(() async {
if (driver != null) {
driver.close();
}
});
test('check if MyDummyWidget is being displayed', () async {
await driver.waitFor(myDummyWidget);
});
});
}
Where the key definition is the required one in the first file, and then, the find.byValueKey and await driver ones are the essentials in the test file.
Don't simply run the test. It is running the pp virtually. So we can't import dart: UI. It'll give the error. Use command
flutter drive --target=test_driver/app.dart to test it.
In Android Studio, right-click on the test file in the Project tree and select "Run". You should see 2 options:
Make sure you select the second option: "tests in widget_test..."
If you select the first option you will see the Error: Not found: 'dart:ui' and you lose the option to make a selection from the Run context menu.
Finally, I got run widget tests in my app.
This soluction worked for me.
I found out why, I chose the first option instead of the flutter test. how silly I was, now removing this wrong test type from configuration and run with flutter test works now.
See the image about run in Android Studio
Just check that you don't have imports which load flutter packages.
In my case I had 'cupertino' package import from my file app_keys.dart which listed all keys in a format Key('<something>').
BUT!! UI tests use Key('<something>') constants for Finder but Integration tests - simple strings.
Reference
I'm using node.js API from compiled Dart app. With package:js bindings for this api's:
#JS('http')
library http;
import "package:js/js.dart";
external Server createServer(
[ void requestListener(IncomingMessage request, ServerResponse response)])
And calling this from main.dart:
import "package:js/js.dart";
import "node_partly.dart" as http;
main() async {
http.Server server = http.createServer(allowInterop(handler));
server.listen(9876);
}
void handler(http.IncomingMessage request, http.ServerResponse response){
response.write("Hello, from dart server! \n");
response.write("You asked for ${request.url}");
print(request.url);
response.end();
}
Everything works fine.
But. Analyzer fails with error
WARNING: The argument type 'JSFunction' cannot be assigned to the
parameter type '(IncomingMessage, ServerResponse) → void'. (
example/main.dart:5)
The problem is that allowInterop produces "JSFunction" - deprecated class for internal use.
And from point of view of annotations - there should be normal "Function" class.
This is annoying if to pay attention to this. And if I will not pay attention to analyzer errors - I may leave real error in my code.
How can I fix it?
P.S. Using latest dart 1.16
Update: created issue at github https://github.com/dart-lang/sdk/issues/26371
For a project, I'm importing a library but I don't use any of the classes in it directly. The goal is to fetch a ClassMirror at runtime to create an instance from it. So I have something like:
import 'controllers.dart';
main() {
ClassMirror controller = getClassFromString(libraryName: 'deck_app', className: 'HomeController');
InstanceMirror instance = controller.newInstance(new Symbol(''), []);
instance.reflectee.sayHey();
}
This gives me an "unused import" error. Idk if this is to be considered a bug. So I'm asking you: do you think this is to be considered as a bug? If not, is there a way I could suppress unused import errors?
What's weird is I thought Dart would tree-shake the source and remove the unused import's code, but it does not. The library is properly imported and available.
The unused import is just a conclusion from the static analyzer. You can ignore it or add a dummy statement to silence the analyzer. This has no effect when you run the application.
package com.scheduler.process;
public class Process {
public enum state {
NOT_SUBMITTED, SUBMITTED, BLOCKED, READY, RUNNING, COMPLETED
}
private state currentState;
public state getCurrentState() {
return currentState;
}
public void setCurrentState(state currentState) {
this.currentState = currentState;
}
}
package com.scheduler.machine;
import com.scheduler.process.Process;
import com.scheduler.process.Process.state;
public class Machine {
com.scheduler.process.Process p = new com.scheduler.process.Process();
state s = state.READY; //fails if I don't also explicitly import Process.state
p.setCurrentState(s); //says I need a declarator id after 's'... this is wrong.
p.setCurrentState(state.READY);
}
Modified the example to try and direct to the issue. I cannot change the state on this code. Eclipse suggests importing Process.state like I had on my previous example, but this doesn't work either. This allows state s = state.READY but the call to p.setCurrentState(s); fails as does p.setCurrentState(state.READY);
Problem continued.... Following Oleg's suggestions I tried more permutations:
package com.scheduler.machine;
import com.scheduler.process.Process;
import com.scheduler.process.Process.*;
public class Machine {
com.scheduler.process.Process p = new com.scheduler.process.Process();
public state s = Process.state.READY;
p.setCurrentState(s);
p.setCurrentState(state.READY);
}
Okay. It's clear now that I'm a candidate for lobotomy.
package com.scheduler.machine;
import com.scheduler.process.Process;
import com.scheduler.process.Process.state;
public class Machine {
public void doStuff(){
com.scheduler.process.Process p = new com.scheduler.process.Process();
state s = state.READY; //fails if I don't also explicitly import Process.state
p.setCurrentState(s); //says I need a declarator id after 's'... this is wrong.
p.setCurrentState(state.READY);
}
}
I needed to have a method in the class--but we're still missing something (probably obvious) here. When I go via the command line and run javac on the Machine class AFTER compiling Process, I still get the following error:
mseil#context:/media/MULTIMEDIA/Scratch/Scratch/src/com/scheduler/machine$ javac Machine.java
Machine.java:3: package com.scheduler.process does not exist
import com.scheduler.process.Process;
^
So I guess the question now becomes, what idiot thing am I missing that is preventing me from compiling this by hand that eclipse is doing for me behind the scene?
======
Problem solved here:
Java generics code compiles in eclipse but not in command line
This has just worked for me:
Download latest Eclipse
Create new project
Create two packages com.scheduler.process and com.scheduler.machine
Create class Process in package com.scheduler.process and class Machine in com.scheduler.machine and copy their contents from your post modifying them to conform to Java language syntax, like this:
Everything compiles right away.
------ to answer the previous version of the question ------
To answer the question as it is right now: you need to either
import com.scheduler.process.Process.status or import com.scheduler.process.Process.* and refer to status as just status
or
import com.scheduler.process.* or import com.scheduler.process.Process and refer to status as Process.status
------ to answer the original version of the question ------
You can't import classes that are not inside some package. You just can't. It is a compile time error to import a type from the unnamed package.
You don't need to import anything if your classes are in the same package, or if all of your classes are packageless.
If Process class was inside some package it would be possible to import just its status inner class: import a.b.c.Process.status would work just fine.
All your Windows/Linux migration issues don't have anything to do with Java and exceptions that you see. import Process.state; will produce exception on any OS because you can't import classes that don't belong to any package.
Eclipse doesn't use the Sun JDK by default. I would assume that you are using Eclipse's built in compiler as Sun's JDK and the OpenJDK are almost identical.
Java code compiles and runs exact the same on Windows and Linux most of the time (unless you use a few of the platform specific operations)
I suspect you are not building the code the same way and when you compile Machine, the Process class has not been compiled.
I suggest you use a standard build system like maven or ant and it will build the same everywhere. Failing that run Eclipse on Linux or just the same .class you use on windows as they don't need to be re-compiled in any case.
BTW: You don't need to import Process.state as it not used and its in the same package (so you wouldn't need to if you did)