<properties>
    <java.version>11</java.version>
    <spring-cloud.version>2020.0.0</spring-cloud.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<repositories>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
    </repository>
</repositories>

post.api.url=http://localhost:9999

{
  "userId": 11,
  "id": 11,
  "title": "Test Title",
  "body": "Test Body"
}

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
import org.springframework.cloud.contract.wiremock.AutoConfigureWireMock;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.util.ResourceUtils;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.Optional;

import static org.junit.jupiter.api.Assertions.*;
import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
import static com.github.tomakehurst.wiremock.client.WireMock.get;
import static com.github.tomakehurst.wiremock.client.WireMock.urlPathEqualTo;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.springframework.http.HttpHeaders.CONTENT_TYPE;

import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
@AutoConfigureWireMock(port = 9999)
public class PostGatewayComponentTest {

    @Autowired
    private PostGateway postGateway;

    @Test
    public void getPostById() throws IOException {
        stubFor(get(urlPathEqualTo("/posts/1"))
                .willReturn(aResponse()
                        .withBody(read("classpath:postApiResponse.json"))
                        .withHeader(CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
                        .withStatus(200)));

        Optional<PostResponse> postResponse = postGateway.getPostById(1);
        assertEquals(11, postResponse.get().getId());
        assertEquals(11, postResponse.get().getUserId());
        assertEquals("Test Title", postResponse.get().getTitle());
        assertEquals("Test Body", postResponse.get().getBody());
    }

    public static String read(String filePath) throws IOException {
        File file = ResourceUtils.getFile(filePath);
        return new String(Files.readAllBytes(file.toPath()));
    }
}