Develop Reference

Unable to run any Junit4 tests - InvalidTestClassError: Invalid test class

I am trying to run Junit4 tests and I am unable to run it. I have the following dependency installed
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
My test class looks like this
package model.validators;
import org.junit.Assert;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
class UserValidatorTest {
#Test
public void shouldReturnTrueForValidPhoneNumbers() {
List<String> phoneNumbers = Arrays.asList(
"9876543210",
"7777543210"
);
boolean result = UserValidator.validateUserPhoneNumbers(phoneNumbers);
Assert.assertTrue(result);
}
}
When I try to run this test, I get the following error
org.junit.runners.model.InvalidTestClassError: Invalid test class 'model.validators.UserValidatorTest':
I am using IntellijIdea. Any idea what is going wrong here ? TIA
Tried changing dependencies, reloading maven project, setting the correct classpath in Junit Run configurations

I can see that your class UserValidatorTest is not public. On making your class public, you will be able to run the tests.
package model.validators;
import org.junit.Assert;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
public class UserValidatorTest {
#Test
public void shouldReturnTrueForValidPhoneNumbers() {
List<String> phoneNumbers = Arrays.asList(
"9876543210",
"7777543210"
);
boolean result = UserValidator.validateUserPhoneNumbers(phoneNumbers);
Assert.assertTrue(result);
}
}

JUnit4 requires everything to be public.
JUnit5 is more tolerant regarding the visibilities of Test classes (Test classes, test methods, and lifecycle methods are not required to be public, but they must not be private).
SonarLint Rule description:
In this context (JUnit5), it is recommended to use the default package visibility, which improves the readability of code.

How to mock S3 in order to test Java code in Junit

I have taken reference form here in order to implement S3 mocking for integration testing
My confusion and the part that i did not get is that how can i use docker here ?
Do i have to install something ?
I have just added below code in my maven
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk-datapipeline</artifactId>
<version>1.11.295</version>
</dependency>
And have written below class
package com.amazonaws.lambda.demo;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.AnonymousAWSCredentials;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.client.builder.AwsClientBuilder.EndpointConfiguration;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Builder;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import io.findify.s3mock.S3Mock;
public class S3Mock {
S3Mock api = new S3Mock.Builder().withPort(8001).withInMemoryBackend().build();
api.start();
AmazonS3Client client = new AmazonS3Client(new AnonymousAWSCredentials());
// use local API mock, not the AWS one
client.setEndpoint("http://127.0.0.1:8001");
client.createBucket("testbucket");
client.putObject("testbucket", "file/name", "contents");
}
But i am not able to compile my class itself .
Can some body help me understand what else i have to do in order to make this work .

I believe you have missed the dependency for S3Mock which comes with below maven:
<dependency>
<groupId>io.findify</groupId>
<artifactId>s3mock_2.12</artifactId>
<version>0.2.5</version>
<scope>test</scope>
</dependency>
Also, I will suggest you rename your class from S3Mock to something like AmazonS3Mock just to avoid namespace confusions

Spring Boot - Rest Assured methods not found

I have a REST API built with Spring Boot.
I am attempting to use Rest-Assured test framework, however I can't seem to get it to work.
I am using the guide from Here
get("/lotto").then().assertThat().body("lotto.lottoId", equalTo(5));
And have added the dependencies to my maven project.
<dependency>
<groupId>com.jayway.restassured</groupId>
<artifactId>rest-assured</artifactId>
<version>2.9.0</version>
<scope>test</scope>
</dependency>
However, It doesn't seem to import the required classes and just prompts me to create a new "get()" method.
My Test class:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(Application.class)
#WebIntegrationTest
public class DemoControllerTest {
#Test
public void test() {
get("/lotto").then().assertThat().body("lotto.lottoId", equalTo(5));
}
}
What am I missing?

What am I missing?
A simple static import, that's missing! In order to resolve the get static method, just use the following static import:
import static com.jayway.restassured.RestAssured.get;

I had similar issue. What I did (using new version 3.0.2):
import io.restassured.RestAssured.*;
import io.restassured.matcher.RestAssuredMatchers.*;
import org.hamcrest.Matchers.*;
Instead of:
import static io.restassured.RestAssured.*;
import static io.restassured.matcher.RestAssuredMatchers.*;
import static org.hamcrest.Matchers.*;
So I had same issue couldnt find the methods ...

Can't resolve symbol toJson

I'm using json4s in a play project, and I'm also using a library called sbt-buildinfo which generates Scala source from your build definitions.
Now, in the sbt-buildinfo library the say you need to add some line of code: buildInfoOptions += BuildInfoOption.ToJson so you can use .toJson, but from some reason I can use .toJson.
this is how I do it:
import _root_.util.{AuthenticatedAction}
import buildinfo.BuildInfo
import com.google.inject.Inject
import org.json4s.BuildInfo
import play.api._
import play.api.mvc._
class AppInfo #Inject()(implicit configuration: Configuration) extends Controller {
def appVerion = AuthenticatedAction {
Ok(BuildInfo.toJson)
}
but the import buildinfo.BuildInfo stays gray....so it looks like I'm not using it. I refreshed the build.sbt and all, what could it be?

You have multiple imports to a BuildInfo object. org.json4s.BuildInfo will probably shadow your buildInfo.BuildInfo import and therefore, it does not have the required member. Try writing out the entire package name that you need:
Ok(buildinfo.BuildInfo.toJson)

Why does Alternator mock DynamoDB fail from maven but not Eclipse?

I have been in touch with the author of Alternator about this issue, and he's as puzzled as I am. The short story: I have written unit tests of code that operates against DynamoDB using the Alternator mocking framework that work fine when I invoke them from within Eclipse, but fail when invoked from maven.
The failure arises from within the AWS SDK itself:
com.amazonaws.AmazonServiceException: [java.lang.Error: property value is null.]
at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:679) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:350) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:202) ~[aws-java-sdk-1.5.5.jar:na]
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.invoke(AlternatorDBClientV2.java:225) ~[alternator-0.6.4.jar:na]
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.updateItem(AlternatorDBClientV2.java:99) ~[alternator-0.6.4.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$2.executeLowLevelRequest(DynamoDBMapper.java:646) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.execute(DynamoDBMapper.java:767) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:658) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:488) ~[aws-java-sdk-1.5.5.jar:na]
at com.somoglobal.eventdata.Controller.addDeviceKeys(Controller.java:531) ~[classes/:na]
which as you can see is not hugely useful as the stack trace itself is just showing the stack at the point where the AWS SDK is assembling an exception from the response received through the (mocked) remote service.
The relevant version numbers:
Maven 3.0.4
Java 1.7.0_10
AWS SDK 1.5.5 (although I've also tried 1.5.3 and 1.5.4)
Eclipse version "Kepler", Build id: 20130614-0229
Burrowing down a bit further, the (slightly elided) pom.xml for the project
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<groupId>snip</groupId>
<artifactId>snip</artifactId>
<version>1.14.2-SNAPSHOT</version>
</parent>
<artifactId>snip</artifactId>
<version>1.6.0-SNAPSHOT</version>
<name>snip</name>
<dependencies>
...snip...
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.5.5</version>
</dependency>
<dependency>
<groupId>com.michelboudreau</groupId>
<artifactId>alternator</artifactId>
<version>0.6.4</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
and the slightly trimmed down test:
package com.xxx;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import org.joda.time.DateTime;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TestRule;
import com.amazonaws.Request;
import com.amazonaws.handlers.RequestHandler;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
import com.amazonaws.services.dynamodbv2.model.AttributeDefinition;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.CreateTableResult;
import com.amazonaws.services.dynamodbv2.model.KeySchemaElement;
import com.amazonaws.services.dynamodbv2.model.KeyType;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughputExceededException;
import com.amazonaws.util.TimingInfo;
import com.michelboudreau.alternator.AlternatorDB;
import com.michelboudreau.alternatorv2.AlternatorDBClientV2;
import com.xxx.stuff;
public class ControllerTest {
private static Controller instance;
private static DynamoDBMapper mapper;
private static AlternatorDB db;
private static AlternatorDBClientV2 client;
#BeforeClass
public static void setup() throws Exception {
client = new AlternatorDBClientV2();
mapper = new DynamoDBMapper(client);
db = new AlternatorDB().start();
// code to create dynamodb was here
instance = new Controller(mapper);
}
#AfterClass
public static void tearDown() throws Exception {
db.stop();
}
#Test
public void testAddDeviceKeys() {
Collection<DeviceKey> keys = EventDataModelMapper.getDeviceKeys(ClassFixtures.event);
assertNotNull("keys should not be null", keys);
assertFalse("keys should not be empty", keys.isEmpty());
boolean result = instance.addDeviceKeys(keys);
assertTrue("result should be true", result);
}
}
The code under test is probably not particularly involved in this failure - I've done sufficient debugging tracing to see that it behaves identically during test when invoked directly through Eclipse, and when run from maven.
EDIT
Actually, Alternator might be implicated in this, as the error message in question could be coming out of com.michelboudreau.alternator.validation.ValidatorUtils:
public static <T> List<Error> rejectIfNull(T property) {
List<Error> errors = new ArrayList<Error>();
if (property == null) {
errors.add(new Error("property value is null."));
}
return errors;
}

Ok stand down, Alternator is not at fault, the problem was ultimately between one of the chairs and keyboards at my workplace. The error message in question was indeed arising from Alternator, and ultimately was sourced to a missing table definition - for very complex reasons when the tests were run through Maven there was a discrepancy between the name of the mock Dynamodb table created through Alternator, and the table name that the code under test was trying to access.
I would like to publicly thank Michel Boudreau for taking the time to respond when I contacted him directly on this matter.

Instead you can run Amazon DynamoDB locally.
http://aws.typepad.com/aws/2013/09/dynamodb-local-for-desktop-development.html

Instead, you can run DynamoDB Local using jcabi-dynamodb-maven-plugin (I'm the developer).