feat: add function for GraphQLTestTemplate to upload files using Upload scalar

Author: tmkhanh

graphql-spring-boot-test/src/main/java/com/graphql/spring/boot/test/GraphQLTestTemplate.java

@@ -16,13 +16,15 @@
 import lombok.NonNull;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.ResponseEntity;
 import org.springframework.lang.Nullable;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StreamUtils;
 
@@ -239,13 +241,23 @@ public GraphQLResponse perform(
       ObjectNode variables,
       List<String> fragmentResources)
       throws IOException {
+    String payload = getPayload(graphqlResource, operationName, variables, fragmentResources);
+    return post(payload);
+  }
+
+  /** Generate GraphQL payload, which consist of 3 elements: query, operationName and variables */
+  private String getPayload(
+      String graphqlResource,
+      String operationName,
+      ObjectNode variables,
+      List<String> fragmentResources)
+      throws IOException {
     StringBuilder sb = new StringBuilder();
     for (String fragmentResource : fragmentResources) {
       sb.append(loadQuery(fragmentResource));
     }
     String graphql = sb.append(loadQuery(graphqlResource)).toString();
-    String payload = createJsonQuery(graphql, operationName, variables);
-    return post(payload);
+    return createJsonQuery(graphql, operationName, variables);
   }
 
   /**
@@ -279,6 +291,76 @@ public GraphQLResponse postMultipart(String query, String variables) {
     return postRequest(RequestFactory.forMultipart(query, variables, headers));
   }
 
+  /**
+   * Handle the multipart files upload request to GraphQL servlet
+   *
+   * <p>In contrast with usual the GraphQL request with body as json payload (consist of query,
+   * operationName and variables), multipart file upload request will use multipart/form-data body
+   * with the following structure:
+   *
+   * <ul>
+   *   <li><b>operations</b> the payload that we used to use for the normal GraphQL request
+   *   <li><b>map</b> a map for referencing between one part of multi-part request and the
+   *       corresponding <i>Upload</i> element inside <i>variables</i>
+   *   <li>a consequence of upload files embedded into the multi-part request, keyed as numeric
+   *       number starting from 1, valued as File payload of usual multipart file upload
+   * </ul>
+   *
+   * <p>Example uploading two files:
+   *
+   * <p>* Please note that we can't embed binary data into json. Clients library supporting graphql
+   * file upload will set variable.files to null for every element inside the array, but each file
+   * will be a part of multipart request. GraphQL Servlet will use <i>map</i> part to walk through
+   * variables.files and validate the request in combination with other binary file parts
+   *
+   * <p>-------------- request beginning ---------------
+   *
+   * <p>operations: { "query": "mutation($files:[Upload]!) {uploadFiles(files:$files)}",
+   * "operationName": "uploadFiles", "variables": { "files": [null, null] } }
+   *
+   * <p>-----------------------------------------------
+   *
+   * <p>map: { "1":["variables.files.0"], "2":["variables.files.1"] }
+   *
+   * <p>-----------------------------------------------
+   *
+   * <p>1: --file 1 binary code--
+   *
+   * <p>-----------------------------------------------
+   *
+   * <p>2: --file 2 binary code--
+   *
+   * <p>-------------- request end ---------------------
+   *
+   * @param graphqlResource path to the classpath resource containing the GraphQL query
+   * @param variables the input variables for the GraphQL query
+   * @param files ClassPathResource instance for each file that will be uploaded to GraphQL server.
+   *     When Spring RestTemplate processes the request, it will automatically produce a valid part
+   *     representing given file inside multipart request (including size, submittedFileName, etc.)
+   * @return {@link GraphQLResponse} containing the result of query execution
+   * @throws IOException if the resource cannot be loaded from the classpath
+   */
+  public GraphQLResponse postFiles(
+      String graphqlResource, ObjectNode variables, List<ClassPathResource> files)
+      throws IOException {
+
+    MultiValueMap<String, Object> values = new LinkedMultiValueMap<>();
+    MultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
+
+    for (int i = 0; i < files.size(); i++) {
+      String valueKey = String.valueOf(i + 1); // map value and part index starts at 1
+      map.add(valueKey, String.format("variables.files.%d", i));
+
+      values.add(valueKey, files.get(i));
+    }
+
+    String payload = getPayload(graphqlResource, null, variables, Collections.emptyList());
+    values.add("operations", payload);
+    values.add("map", map);
+
+    return postRequest(RequestFactory.forMultipart(values, headers));
+  }
+
   /**
    * Performs a GraphQL request with the provided payload.
    *

graphql-spring-boot-test/src/main/java/com/graphql/spring/boot/test/RequestFactory.java

@@ -4,6 +4,7 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 
 class RequestFactory {
 
@@ -23,4 +24,10 @@ static HttpEntity<Object> forMultipart(String query, String variables, HttpHeade
     values.add("variables", forJson(variables, new HttpHeaders()));
     return new HttpEntity<>(values, headers);
   }
+
+  static HttpEntity<Object> forMultipart(
+      MultiValueMap<String, Object> values, HttpHeaders headers) {
+    headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+    return new HttpEntity<>(values, headers);
+  }
 }

graphql-spring-boot-test/src/test/java/com/graphql/spring/boot/test/GraphQLTestTemplateIntegrationTest.java

@@ -1,18 +1,23 @@
 package com.graphql.spring.boot.test;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.graphql.spring.boot.test.beans.FooBar;
 import graphql.GraphQLError;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.UUID;
+import java.util.stream.Collectors;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.http.HttpHeaders;
 
@@ -26,9 +31,11 @@ class GraphQLTestTemplateIntegrationTest {
   private static final String QUERY_WITH_VARIABLES = "query-with-variables.graphql";
   private static final String COMPLEX_TEST_QUERY = "complex-query.graphql";
   private static final String MULTIPLE_QUERIES = "multiple-queries.graphql";
+  private static final String UPLOAD_MUTATION = "upload-files.graphql";
   private static final String INPUT_STRING_VALUE = "input-value";
   private static final String INPUT_STRING_NAME = "input";
   private static final String INPUT_HEADER_NAME = "headerName";
+  private static final String FILES_STRING_NAME = "files";
   private static final String TEST_HEADER_NAME = "x-test";
   private static final String TEST_HEADER_VALUE = String.valueOf(UUID.randomUUID());
   private static final String FOO = "FOO";
@@ -39,6 +46,7 @@ class GraphQLTestTemplateIntegrationTest {
   private static final String DATA_FIELD_OTHER_QUERY = "$.data.otherQuery";
   private static final String DATA_FIELD_QUERY_WITH_HEADER = "$.data.queryWithHeader";
   private static final String DATA_FIELD_DUMMY = "$.data.dummy";
+  private static final String DATA_FILE_UPLOAD_FILES = "$.data.uploadFiles";
   private static final String OPERATION_NAME_WITH_VARIABLES = "withVariable";
   private static final String OPERATION_NAME_TEST_QUERY_1 = "testQuery1";
   private static final String OPERATION_NAME_TEST_QUERY_2 = "testQuery2";
@@ -224,4 +232,24 @@ void testPost() {
         .asString()
         .isEqualTo(TEST_HEADER_VALUE);
   }
+
+  @Test
+  @DisplayName("Test perform with file uploads.")
+  void testPerformWithFileUploads() throws IOException {
+    // GIVEN
+    final ObjectNode variables = objectMapper.createObjectNode();
+    ArrayNode nodes = objectMapper.valueToTree(Arrays.asList(null, null));
+    variables.putArray(FILES_STRING_NAME).addAll(nodes);
+
+    List<String> fileNames = List.of("multiple-queries.graphql", "simple-test-query.graphql");
+    List<ClassPathResource> testUploadFiles =
+        fileNames.stream().map(ClassPathResource::new).collect(Collectors.toList());
+    // WHEN - THEN
+    graphQLTestTemplate
+        .postFiles(UPLOAD_MUTATION, variables, testUploadFiles)
+        .assertThatNoErrorsArePresent()
+        .assertThatField(DATA_FILE_UPLOAD_FILES)
+        .asListOf(String.class)
+        .isEqualTo(fileNames);
+  }
 }

graphql-spring-boot-test/src/test/java/com/graphql/spring/boot/test/beans/DummyMutation.java

@@ -0,0 +1,27 @@
+package com.graphql.spring.boot.test.beans;
+
+import graphql.kickstart.servlet.apollo.ApolloScalars;
+import graphql.kickstart.tools.GraphQLMutationResolver;
+import graphql.schema.DataFetchingEnvironment;
+import graphql.schema.GraphQLScalarType;
+import java.util.List;
+import java.util.stream.Collectors;
+import javax.servlet.http.Part;
+import org.springframework.context.annotation.Bean;
+import org.springframework.stereotype.Service;
+
+@Service
+public class DummyMutation implements GraphQLMutationResolver {
+
+  @Bean
+  private GraphQLScalarType getUploadScalar() {
+    // since the test doesn't inject this built-in Scalar,
+    // so we inject here for test run purpose
+    return ApolloScalars.Upload;
+  }
+
+  public List<String> uploadFiles(List<Part> files, DataFetchingEnvironment env) {
+    List<Part> actualFiles = env.getArgument("files");
+    return actualFiles.stream().map(Part::getSubmittedFileName).collect(Collectors.toList());
+  }
+}

graphql-spring-boot-test/src/test/resources/test-schema.graphqls

@@ -1,3 +1,5 @@
+scalar Upload
+
 type FooBar {
     foo: String!
     bar: String!
@@ -17,4 +19,8 @@ type Query {
     fooBar(foo: String, bar: String): FooBar!
     queryWithVariables(input: String!): String!
     queryWithHeader(headerName: String!): String
+}
+
+type Mutation {
+    uploadFiles(files: [Upload]!): [String!]
 }

graphql-spring-boot-test/src/test/resources/upload-files.graphql

@@ -0,0 +1,3 @@
+mutation($files: [Upload]!) {
+    uploadFiles(files: $files)
+}