Why Log.d() print nothing when running Android Local Unit Test?

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I'm trying to print something when running Android Local Unit Test, but nothing's happening. What's the matter? How can I fix it?

I consulted some documents on http://developer.android.com, found that Android Local Unit Test just run on my machine's JVM, the android.jar file that is used to run unit tests does not contain any actual code, so Log.d() print nothing. If i wanna print log, how can i do?

Here is my code, FeedbackModelTest.java located in src/test/main directory.

package com.upward.reader.mvp.model;

import android.util.Log;

import com.upward.reader.mvp.bean.FeedbackBean;
import com.upward.reader.net.RequestJSONCallback;

import org.junit.Test;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class FeedbackModelTest {

@Test
public void postFeedback() throws Exception {
    final String url = "http://test.guguread.com/interface/app/user/feedback?";
    Map<String, String> params = new HashMap<>();
    params.put("content", "content");
    new FeedbackModel().postFeedback(url, params, new RequestJSONCallback<FeedbackBean>() {

        @Override
        public void onResponse(FeedbackBean result) throws IOException {
            Log.d("TAG", result.toString());
        }

        @Override
        public void onFailure(Exception e) {
            e.printStackTrace();
        }

    });
}

}

You should use standard output, System.out.println("Hello StackOverflow") intead of Log.x(). Then you can see the log info in the run tab.

2017/12/16 Update: If you can't see the output on the Run tab, go to Android Monitor tab to find the output instead.

Why Log.d() print nothing when running Android Local Unit Test , Verbose and Debug logs have special handling; An exception trace is printed when the exception is Filtering logs; Logs in JUnit tests. Overview. Logging used to be done using Android's android.util.Log. A wrapper on that is now Log​.v and Log.d Calls made using org.chromium.base. toString(); } public void bar​() { . To run your local unit tests, follow these steps: Be sure your project is synchronized with Gradle by clicking Sync Project in the toolbar. Run your test in one of the following ways: To run a single test, open the Project window, and then right-click a test and click Run. To test all methods in a class, right-click a class or method in the

I suggest you to use interface:

interface PlatformLog {
    fun e(tag: String, msg: String, throwable: Throwable?=null)
    fun i(tag: String, msg: String)
}

create an interface for example:

in unit tests:

class SystemPlatformLog : PlatformLog {
    override fun i(tag: String, msg: String) {
        println("$tag : $msg")
    }

    override fun e(tag: String, msg: String, throwable: Throwable?) {
        println("$tag : $msg")
    }
}

In android

class AndroidPlatformLog : PlatformLog {
                override fun i(tag: String, msg: String) {
                    Log.i(tag, msg)
                }

                override fun e(tag: String, msg: String, throwable: Throwable?) {
                    Log.e(tag, msg, throwable)
                }
            }

Usage: In android

private val log: PlatformLog = AndroidPlatformLog()

public override fun onCreate(savedInstanceState: Bundle?) {
    log.i(TAG, "onCreate $savedInstanceState")
}

In tests

private val log: PlatformLog = SystemPlatformLog()

@Test
fun `should log in System`() {
    log.i(TAG, "called from tests")
}

OR with dagger2 in two cases:

@Inject lateinit var log: PlatformLog

public override fun onCreate(savedInstanceState: Bundle?) {
    log.i(TAG, "onCreate $savedInstanceState")
}

in tests

class MyTest{

@Inject lateinit var log: PlatformLog

@Before
fun setUp() {
    val component = DaggerTestComponent.builder().testModule(TestModule()).build()
        component.inject(this)
}

@Test
fun `should log in System`() {
    log.i(TAG, "called from tests")
}
@Module
open class TestModule {

    @Provides
    @Singleton
    open fun providePlatformLog(): PlatformLog {
        return SystemPlatformLog()
    }
}
@Singleton
@Component(modules = [TestModule::class])
interface TestComponent {
    fun inject(test: MyTest)
}

Logging, printing this PDF and keeping it nearby as you learn to use Android Studio. Strings, and that it also generated a local variable called greeting with the singular involved a lot of assets, you should still run your tests to verify that you have not introduced uses the Log.d() method that writes text to the Android debug logs. Jeff T. Apparently, this user prefers to keep an air of mystery about them. 46 Why Log.d() print nothing when running Android Local Unit Test? 8 Debugging

From Unit Testing Support:

The android.jar file that is used to run unit tests does not contain any actual code - that is provided by the Android system image on real devices. Instead, all methods throw exceptions (by default). This is to make sure your unit tests only test your code and do not depend on any particular behaviour of the Android platform (that you have not explicitly mocked e.g. using Mockito). If that proves problematic, you can add the snippet below to your build.gradle to change this behavior:

  android {
  // ...
  testOptions { 
    unitTests.returnDefaultValues = true
  }
}

Android Studio, When you run, debug, or test your code Android Studio uses a run/debug configuration to For a local unit test, you can optionally run with code coverage. -d -r. Default: no options. Launch Options: Launch. Select an option: Nothing - Don't For a complete list of log commands, enter the log list command from an LLDB  For testing Android apps, you typically create these types of automated unit tests: Local tests: Unit tests that run on your local machine only. These tests are compiled to run locally on the Java Virtual Machine (JVM) to minimize execution time. If your tests depend on objects in the Android framework, we recommend using Robolectric.

If you need to involve some form of Android-related code in your tests (which Log.d is), you can use a testing framework such as Robolectric which is designed to act like the Android.jar code that your code references. By configuring your test runner to run in Robolectric, and setting the proper config flag in robolectric's config annotations, you can enable logging using their logging methods.

Create and edit run/debug configurations, Test your app View your app logs; Write log messages; Logcat message format Note that you can configure the logcat output display, but not the Run window. After selecting your print preferences in the dialog that appears, you can V: Verbose (lowest priority); D: Debug; I: Info; W: Warning; E: Error  Run instrumented unit tests. To run your instrumented tests, follow these steps: Be sure your project is synchronized with Gradle by clicking Sync Project in the toolbar. Run your test in one of the following ways: To run a single test, open the Project window, and then right-click a test and click Run.

Popular Science, Why Log.d() print nothing when running Android Local Unit Test? par Unknown à 07:51. Libellés : Newest questions tagged unit-testing - Stack Overflow  For more information about local unit tests, see Building local unit tests. View the test results. When you run a JUnit or instrumented test, the results appear in the Run window. A green bar means all tests succeeded and a red bar means at least one test failed. Figure 3 shows a successful test run. Figure 3. Test results appear in the Run window.

Write and View Logs with Logcat, In the normal run of tests the LOG() macro does nothing but if needed a (or --​gtest_verbose=2) flag to have that additional debug information printed to the This is CppUTest is a C /C++ based unit xUnit test framework for unit testing and a regular WebRTC checkout with the Android-specific parts added. blob Aug 31,  Ok, we want to start unit test our code, how do we start? Step 1: Refactor your code from MVC (Model-View-Controller — reads “everything in Activity”) to MVP (Model-View-Presenter — easiest to start with; testing the ViewModel in MVVM (Model-View-ViewModel) is the same as testing the Presenter in MVP, refactoring takes more effort though).

Why Log.d() print nothing when running Android Local , Learn Unit Testing in Android by building a sample application. This annotation is used to mark any method to run before executing the test cases. Here we initialize mSharedPreferenceEntry

Comments
  • If by "local unit test", you mean that you are running the tests directly on your JVM (e.g., test/ in Android Studio, not androidTest/), there is no LogCat, so I would not expect to see that text anywhere.
  • It would be better to cut an paste the code as text in the question.
  • Yep, I'm running the tests on jvm, the test code located in src/test/java floder. Do you know how to print log in this case?
  • Log prints to LogCat, which I doubt would be running for the local unit test. Not sure, though...
  • Your image of text isn't very helpful. It can't be copied into an editor, and it doesn't index very well, making other users with the same problem less likely to find the answer here. Please edit your post to incorporate the relevant text directly (preferably using copy+paste to avoid transcription errors).
  • That's funny. Why can't there be some magic to do that automatically with Log / Timber statements I wonder?