FEAT: Implement enabling auto merge for PR by GraphQL

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

@@ -629,6 +629,66 @@ public enum MergeMethod {
         REBASE
     }
 
+    /**
+     * Request to enable auto merge for a pull request.
+     *
+     * @param authorEmail
+     *            The email address to associate with this merge.
+     * @param clientMutationId
+     *            A unique identifier for the client performing the mutation.
+     * @param commitBody
+     *            Commit body to use for the commit when the PR is mergable; if omitted, a default message will be used.
+     *            NOTE: when merging with a merge queue any input value for commit message is ignored.
+     * @param commitHeadline
+     *            Commit headline to use for the commit when the PR is mergable; if omitted, a default message will be
+     *            used. NOTE: when merging with a merge queue any input value for commit headline is ignored.
+     * @param expectedHeadOid
+     *            The expected head OID of the pull request.
+     * @param mergeMethod
+     *            The merge method to use. If omitted, defaults to `MERGE`. NOTE: when merging with a merge queue any
+     *            input value for merge method is ignored.
+     * @throws IOException
+     *             the io exception
+     */
+    public void enablePullRequestAutoMerge(String authorEmail,
+            String clientMutationId,
+            String commitBody,
+            String commitHeadline,
+            String expectedHeadOid,
+            MergeMethod mergeMethod) throws IOException {
+
+        StringBuilder inputBuilder = new StringBuilder();
+        addParameter(inputBuilder, "pullRequestId", this.getNodeId());
+        addOptionalParameter(inputBuilder, "authorEmail", authorEmail);
+        addOptionalParameter(inputBuilder, "clientMutationId", clientMutationId);
+        addOptionalParameter(inputBuilder, "commitBody", commitBody);
+        addOptionalParameter(inputBuilder, "commitHeadline", commitHeadline);
+        addOptionalParameter(inputBuilder, "expectedHeadOid", expectedHeadOid);
+        addOptionalParameter(inputBuilder, "mergeMethod", mergeMethod);
+
+        String graphqlBody = "mutation EnableAutoMerge { enablePullRequestAutoMerge(input: {" + inputBuilder + "}) { "
+                + "pullRequest { id } } }";
+
+        root().createGraphQLRequest(graphqlBody).sendGraphQL();
+
+        refresh();
+    }
+
+    private void addOptionalParameter(StringBuilder inputBuilder, String name, Object value) {
+        if (value != null) {
+            addParameter(inputBuilder, name, value);
+        }
+    }
+
+    private void addParameter(StringBuilder inputBuilder, String name, Object value) {
+        Objects.requireNonNull(value);
+        String formatString = " %s: \"%s\"";
+        if (value instanceof Enum) {
+            formatString = " %s: %s";
+        }
+
+        inputBuilder.append(String.format(formatString, name, value));
+    }
     /**
      * The status of auto merging a {@linkplain GHPullRequest}.
      *

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

@@ -1299,6 +1299,21 @@ 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")
+                .rateLimit(RateLimitTarget.GRAPHQL)
+                .with("query", query)
+                .withUrlPath("/graphql");
+    }
+
     /**
      * Intern.
      *

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.internal.graphql.response.GHGraphQLResponse;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -103,6 +104,37 @@ public <T> T fetchInto(@Nonnull T existingInstance) throws IOException {
                 .body();
     }
 
+    /**
+     * Sends a GraphQL request with no response
+     *
+     * @throws IOException
+     *             the io exception
+     */
+    public void sendGraphQL() throws IOException {
+        fetchGraphQL(GHGraphQLResponse.ObjectResponse.class);
+    }
+
+    /**
+     * 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 extends GHGraphQLResponse<S>, S> S fetchGraphQL(@Nonnull Class<T> type) throws IOException {
+        T response = fetch(type);
+
+        if (!response.isSuccessful()) {
+            throw new IOException("GraphQL request failed by:" + response.getErrorMessages());
+        }
+
+        return response.getData();
+    }
+
     /**
      * 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/internal/graphql/response/GHGraphQLResponse.java

@@ -0,0 +1,93 @@
+package org.kohsuke.github.internal.graphql.response;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+import java.util.Collections;
+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<GraphQLError> errors;
+
+    /**
+     * @param data
+     *            GraphQL success response
+     * @param errors
+     *            GraphQL failure response, This will be empty if not fail
+     */
+    @JsonCreator
+    @SuppressFBWarnings(value = { "EI_EXPOSE_REP2" }, justification = "Spotbugs also doesn't like this")
+    public GHGraphQLResponse(@JsonProperty("data") T data, @JsonProperty("errors") List<GraphQLError> errors) {
+        if (errors == null) {
+            errors = Collections.emptyList();
+        }
+        this.data = data;
+        this.errors = Collections.unmodifiableList(errors);
+    }
+
+    /**
+     * @return request is succeeded. True when error list is empty.
+     */
+    public boolean isSuccessful() {
+        return errors.isEmpty();
+    }
+
+    /**
+     * @return GraphQL success response
+     */
+    public T getData() {
+        if (!isSuccessful()) {
+            throw new RuntimeException("Response not successful, data invalid");
+        }
+
+        return data;
+    }
+
+    /**
+     * @return GraphQL error messages from Github Response. Empty list when no errors occurred.
+     */
+    public List<String> getErrorMessages() {
+        return errors.stream().map(GraphQLError::getMessage).collect(Collectors.toList());
+    }
+
+    /**
+     * A error of GraphQL response. Minimum implementation for GraphQL error.
+     */
+    @SuppressFBWarnings(value = { "UWF_UNWRITTEN_FIELD", "UWF_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR" },
+            justification = "JSON API")
+    private static class GraphQLError {
+        private String message;
+
+        public String getMessage() {
+            return message;
+        }
+    }
+
+    /**
+     * A GraphQL response with basic Object data type.
+     */
+    public static class ObjectResponse extends GHGraphQLResponse<Object> {
+        /**
+         * {@inheritDoc}
+         */
+        @JsonCreator
+        @SuppressFBWarnings(value = { "EI_EXPOSE_REP2" }, justification = "Spotbugs also doesn't like this")
+        public ObjectResponse(@JsonProperty("data") Object data, @JsonProperty("errors") List<GraphQLError> errors) {
+            super(data, errors);
+        }
+    }
+}

src/main/resources/META-INF/native-image/org.kohsuke/github-api/reflect-config.json

@@ -6703,5 +6703,95 @@
     "allDeclaredMethods": true,
     "allPublicClasses": true,
     "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse$EnablePullRequestAutoMerge",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse$EnablePullRequestAutoMerge$EnablePullRequestAutoMergePullRequest",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse$GraphQLError",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse$ObjectResponse",
+    "allPublicFields": true,
+    "allDeclaredFields": true,
+    "queryAllPublicConstructors": true,
+    "queryAllDeclaredConstructors": true,
+    "allPublicConstructors": true,
+    "allDeclaredConstructors": true,
+    "queryAllPublicMethods": true,
+    "queryAllDeclaredMethods": true,
+    "allPublicMethods": true,
+    "allDeclaredMethods": true,
+    "allPublicClasses": true,
+    "allDeclaredClasses": true
   }
 ]

src/main/resources/META-INF/native-image/org.kohsuke/github-api/serialization-config.json

@@ -1342,5 +1342,23 @@
   },
   {
     "name": "org.kohsuke.github.SkipFromToString"
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse"
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse$EnablePullRequestAutoMerge"
+  },
+  {
+    "name": "org.kohsuke.github.GHPullRequest$EnablePullRequestAutoMergeResponse$EnablePullRequestAutoMerge$EnablePullRequestAutoMergePullRequest"
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse"
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse$GraphQLError"
+  },
+  {
+    "name": "org.kohsuke.github.internal.graphql.response.GHGraphQLResponse$ObjectResponse"
   }
 ]

src/test/java/org/kohsuke/github/GHPullRequestMockTest.java

@@ -33,5 +33,4 @@ public void shouldMockGHPullRequest() throws IOException {
 
         assertThat("Mock should return true", pullRequest.isDraft());
     }
-
 }