feat: implement support for general GraphQL Request and Response

Author: nyatda0116

src/main/java/org/kohsuke/github/GitHub.java

@@ -1299,6 +1299,18 @@ Requester createRequest() {
         return requester;
     }
 
+    /**
+     * Creates a request to GitHub GraphQL API.
+     *
+     * @param query
+     *            the query for the GraphQL
+     * @return the requester
+     */
+    @Nonnull
+    Requester createGraphQLRequest(String query) {
+        return createRequest().method("POST").with("query", query).withUrlPath("/graphql");
+    }
+
     /**
      * Intern.
      *

src/main/java/org/kohsuke/github/GitHubResponse.java

@@ -1,10 +1,10 @@
 package org.kohsuke.github;
 
 import com.fasterxml.jackson.core.JsonParseException;
-import com.fasterxml.jackson.databind.InjectableValues;
-import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.*;
 import org.apache.commons.io.IOUtils;
 import org.kohsuke.github.connector.GitHubConnectorResponse;
+import org.kohsuke.github.graphql.response.GHGraphQLResponse;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -136,6 +136,45 @@ static <T> T parseBody(GitHubConnectorResponse connectorResponse, T instance) th
         }
     }
 
+    /**
+     * Parses a {@link GitHubConnectorResponse} body into a new instance of {@code GHGraphQLResponse<T>}.
+     *
+     * @param <T>
+     *            the type
+     * @param connectorResponse
+     *            the response info to parse.
+     * @param type
+     *            the type to be constructed in GraphQLResponse.
+     * @return GHGraphQLResponse
+     *
+     * @throws IOException
+     *             if there is an I/O Exception.
+     */
+    @CheckForNull
+    static <T> GHGraphQLResponse<T> parseGraphQLBody(GitHubConnectorResponse connectorResponse, Class<T> type)
+            throws IOException {
+        if (connectorResponse.statusCode() == HTTP_NO_CONTENT) {
+            if (type != null && type.isArray()) {
+                T emptyArray = type.cast(Array.newInstance(type.getComponentType(), 0));
+                return new GHGraphQLResponse<>(emptyArray, null);
+            } else {
+                return new GHGraphQLResponse<>(null, null);
+            }
+        }
+
+        String data = getBodyAsString(connectorResponse);
+        try {
+            ObjectReader objectReader = GitHubClient.getMappingObjectReader(connectorResponse);
+            JavaType targetType = objectReader.getTypeFactory().constructParametricType(GHGraphQLResponse.class, type);
+            ObjectReader targetReader = objectReader.forType(targetType);
+            return targetReader.readValue(data);
+        } catch (JsonMappingException | JsonParseException e) {
+            String message = "Failed to deserialize: " + data;
+            LOGGER.log(Level.FINE, message);
+            throw e;
+        }
+    }
+
     /**
      * Gets the body of the response as a {@link String}.
      *

src/main/java/org/kohsuke/github/Requester.java

@@ -27,6 +27,7 @@
 import org.apache.commons.io.IOUtils;
 import org.kohsuke.github.connector.GitHubConnectorResponse;
 import org.kohsuke.github.function.InputStreamFunction;
+import org.kohsuke.github.graphql.response.GHGraphQLResponse;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -103,6 +104,22 @@ public <T> T fetchInto(@Nonnull T existingInstance) throws IOException {
                 .body();
     }
 
+    /**
+     * Sends a request and parses the response into the given type via databinding in graphQL response.
+     *
+     * @param <T>
+     *            the type parameter
+     * @param type
+     *            the type
+     * @return an instance of {@code GHGraphQLResponse<T>}
+     * @throws IOException
+     *             if the server returns 4xx/5xx responses.
+     */
+    public <T> GHGraphQLResponse<T> fetchGraphQLResponse(@Nonnull Class<T> type) throws IOException {
+        return client.sendRequest(this, connectorResponse -> GitHubResponse.parseGraphQLBody(connectorResponse, type))
+                .body();
+    }
+
     /**
      * Makes a request and just obtains the HTTP status code. Method does not throw exceptions for many status codes
      * that would otherwise throw.

src/main/java/org/kohsuke/github/graphql/response/GHGraphQLResponse.java

@@ -0,0 +1,68 @@
+package org.kohsuke.github.graphql.response;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * A response of GraphQL.
+ * <p>
+ * This class is used to parse the response of GraphQL.
+ * </p>
+ *
+ * @param <T>
+ *            the type of data
+ */
+public class GHGraphQLResponse<T> {
+
+    private final T data;
+
+    private final List<GHGraphQLError> errors;
+
+    @JsonCreator
+    @SuppressFBWarnings(value = { "EI_EXPOSE_REP2" }, justification = "Spotbugs also doesn't like this")
+    public GHGraphQLResponse(@JsonProperty("data") T data, @JsonProperty("errors") List<GHGraphQLError> errors) {
+        this.data = data;
+        this.errors = errors;
+    }
+
+    public Boolean isSuccessful() {
+        return errors == null || errors.isEmpty();
+    }
+
+    public T getData() {
+        if (!isSuccessful()) {
+            throw new RuntimeException("This response is Errors occurred response");
+        }
+
+        return data;
+    }
+
+    public List<String> getErrorMessages() {
+        if (isSuccessful()) {
+            throw new RuntimeException("No errors occurred");
+        }
+
+        return errors.stream().map(GHGraphQLError::getErrorMessage).collect(Collectors.toList());
+    }
+
+    /**
+     * A error of GraphQL response. Minimum implementation for GraphQL error.
+     */
+    private static class GHGraphQLError {
+
+        private final String errorMessage;
+
+        @JsonCreator
+        public GHGraphQLError(@JsonProperty("message") String errorMessage) {
+            this.errorMessage = errorMessage;
+        }
+
+        public String getErrorMessage() {
+            return errorMessage;
+        }
+    }
+}