Simple first version of graphql client

Author: oliemansm

gradle.properties

@@ -13,6 +13,11 @@ PROJECT_DEV_NAME = Michiel Oliemans
 
 LIB_PROJECT_REACTOR_VER = 1.0.1
 
+### Test libraries
+
+LIB_GRAPHQL_TOOLS_VER = 6.0.0
+LIB_GRAPHQL_SPRING_VER = 7.0.0
+
 ### Gradle Plugins
 
 LIB_SPRING_BOOT_VER = 2.2.5.RELEASE

graphql-webclient-spring-boot-autoconfigure/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLWebClientAutoConfiguration.java

@@ -0,0 +1,27 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Slf4j
+@Configuration
+@ComponentScan(basePackageClasses = GraphQLWebClientImpl.class)
+public class GraphQLWebClientAutoConfiguration {
+
+  @Bean
+  @ConditionalOnMissingBean
+  public WebClient webClient() {
+    return null;
+  }
+
+  @Bean
+  @ConditionalOnMissingBean
+  public GraphQLWebClient graphQLWebClient(WebClient webClient) {
+    return new GraphQLWebClientImpl(webClient);
+  }
+
+}

graphql-webclient-spring-boot-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+graphql.kickstart.spring.webclient.boot.GraphQLWebClientAutoConfiguration

graphql-webclient/build.gradle

@@ -1,3 +1,9 @@
 dependencies {
     compileOnly "org.springframework.boot:spring-boot-starter-webflux"
+
+    testImplementation "org.springframework.boot:spring-boot-starter-webflux"
+    testImplementation "org.springframework.boot:spring-boot-starter-test"
+    testImplementation "com.graphql-java-kickstart:graphql-kickstart-spring-boot-starter-webflux:$LIB_GRAPHQL_SPRING_VER"
+    testImplementation "com.graphql-java-kickstart:graphql-kickstart-spring-boot-starter-tools:$LIB_GRAPHQL_SPRING_VER"
+    testImplementation "com.graphql-java-kickstart:graphql-java-tools:$LIB_GRAPHQL_TOOLS_VER"
 }

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/GraphQLWebClient.java

@@ -0,0 +1,14 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import lombok.Builder;
+import lombok.Value;
+
+@Value
+@Builder
+class GraphQLRequest {
+
+  String query;
+  Object variables;
+  String operationName;
+
+}

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLRequest.java

@@ -0,0 +1,18 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import lombok.Data;
+
+@Data
+class GraphQLResponse {
+
+  private Map<String, Object> data;
+  private List<String> errors;
+
+  <T> T getFirstObject(Class<T> type) {
+    return (T) data.entrySet().stream().findFirst().map(Entry::getValue).orElseThrow();
+  }
+
+}

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLResponse.java

@@ -0,0 +1,10 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import java.util.Map;
+import reactor.core.publisher.Mono;
+
+public interface GraphQLWebClient {
+
+  <T> Mono<T> query(String resource, Map<String, Object> variables, Class<T> returnType);
+
+}

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLWebClient.java

@@ -0,0 +1,52 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+import lombok.RequiredArgsConstructor;
+import lombok.SneakyThrows;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.MediaType;
+import org.springframework.util.StreamUtils;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+@Slf4j
+@RequiredArgsConstructor
+class GraphQLWebClientImpl implements GraphQLWebClient {
+
+  private final WebClient webClient;
+
+  @Override
+  public <T> Mono<T> query(String resource, Map<String, Object> variables, Class<T> returnType) {
+    GraphQLRequest request = GraphQLRequest.builder()
+        .query(loadQuery(resource))
+        .variables(variables)
+        .build();
+
+    return webClient.post()
+        .uri("/graphql")
+        .contentType(MediaType.APPLICATION_JSON)
+        .bodyValue(request)
+        .retrieve()
+        .bodyToMono(GraphQLResponse.class)
+        .map(it -> it.getFirstObject(returnType));
+  }
+
+  @SneakyThrows
+  private String loadQuery(String path) {
+//    Resource resource = resourceLoader.getResource("classpath:" + location);
+    return loadResource(new ClassPathResource(path));
+  }
+
+  private String loadResource(Resource resource) throws IOException {
+    try (InputStream inputStream = resource.getInputStream()) {
+      return StreamUtils.copyToString(inputStream, StandardCharsets.UTF_8);
+    }
+  }
+
+}

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLWebClientImpl.java

@@ -0,0 +1,13 @@
+package graphql.kickstart.spring.webclient;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class TestApplication {
+
+  public static void main(String[] args) {
+    SpringApplication.run(TestApplication.class, args);
+  }
+
+}

graphql-webclient/src/test/java/graphql/kickstart/spring/webclient/TestApplication.java

@@ -0,0 +1,37 @@
+package graphql.kickstart.spring.webclient.boot;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+class GraphQLWebClientTest {
+
+  @LocalServerPort
+  private int randomServerPort;
+
+  private GraphQLWebClient graphqlClient;
+
+  @BeforeEach
+  void beforeEach() {
+    WebClient webClient = WebClient.builder()
+        .baseUrl("http://localhost:" + randomServerPort)
+        .build();
+    graphqlClient = new GraphQLWebClientImpl(webClient);
+  }
+
+  @Test
+  void queryWithoutVariablesSucceeds() {
+    Mono<String> response = graphqlClient.query("query-test.graphql", null, String.class);
+    assertNotNull("response should not be null", response);
+    assertEquals("response should equal 'test'", "test", response.block());
+  }
+
+}

graphql-webclient/src/test/java/graphql/kickstart/spring/webclient/boot/GraphQLWebClientTest.java

@@ -0,0 +1,17 @@
+package graphql.kickstart.spring.webclient.testapp;
+
+import graphql.kickstart.tools.GraphQLQueryResolver;
+import org.springframework.stereotype.Component;
+
+@Component
+class Query implements GraphQLQueryResolver {
+
+  String test() {
+    return "test";
+  }
+
+  String echo(String value) {
+    return value;
+  }
+
+}

graphql-webclient/src/test/java/graphql/kickstart/spring/webclient/testapp/Query.java

@@ -0,0 +1,3 @@
+query {
+    test
+}

graphql-webclient/src/test/resources/query-test.graphql

@@ -0,0 +1,4 @@
+type Query {
+    test: String!
+    echo(value: String!): String!
+}