JUnit ErrorCollector example

MyTest.java

package com.foo;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ErrorCollector;

import static org.hamcrest.Matchers.equalTo;

/**
 * Created: 12/04/19 17:12
 *
 * @author chris
 */
public class MyTest {
    @Rule
    public ErrorCollector collector = new ErrorCollector();

    @Test
    public void myTest() {
        collector.checkThat("a", equalTo("b"));
        collector.checkThat(1, equalTo(2));
    }
}

output.txt

java.lang.AssertionError: 
Expected: "b"
     got: "a"
 <Click to see difference>

	at org.junit.Assert.assertThat(Assert.java:780)
	at org.junit.rules.ErrorCollector$1.call(ErrorCollector.java:66)
	at org.junit.rules.ErrorCollector.checkSucceeds(ErrorCollector.java:79)
	at org.junit.rules.ErrorCollector.checkThat(ErrorCollector.java:64)
	at org.junit.rules.ErrorCollector.checkThat(ErrorCollector.java:55)
	at com.foo.MyTest.myTest(MyTest.java:20)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.rules.Verifier$1.evaluate(Verifier.java:33)
	at org.junit.rules.RunRules.evaluate(RunRules.java:18)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:76)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:182)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:62)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)


java.lang.AssertionError: 
Expected: <2>
     got: <1>
 <Click to see difference>

	at org.junit.Assert.assertThat(Assert.java:780)
	at org.junit.rules.ErrorCollector$1.call(ErrorCollector.java:66)
	at org.junit.rules.ErrorCollector.checkSucceeds(ErrorCollector.java:79)
	at org.junit.rules.ErrorCollector.checkThat(ErrorCollector.java:64)
	at org.junit.rules.ErrorCollector.checkThat(ErrorCollector.java:55)
	at com.foo.MyTest.myTest(MyTest.java:21)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.rules.Verifier$1.evaluate(Verifier.java:33)
	at org.junit.rules.RunRules.evaluate(RunRules.java:18)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:76)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:182)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:62)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

Thank you. This is useful.