Provide support for External Group operations

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

@@ -0,0 +1,69 @@
+package org.kohsuke.github;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.Optional;
+import java.util.logging.Logger;
+
+/**
+ * Utility class for helping with operations for enterprise managed resources.
+ *
+ * @author Miguel Esteban Gutiérrez
+ */
+class EnterpriseManagedSupport {
+
+    static final String COULD_NOT_RETRIEVE_ORGANIZATION_EXTERNAL_GROUPS = "Could not retrieve organization external groups";
+    static final String NOT_PART_OF_EXTERNALLY_MANAGED_ENTERPRISE_ERROR = "This organization is not part of externally managed enterprise.";
+    static final String TEAM_CANNOT_BE_EXTERNALLY_MANAGED_ERROR = "This team cannot be externally managed since it has explicit members.";
+
+    private static final Logger LOGGER = Logger.getLogger(EnterpriseManagedSupport.class.getName());
+
+    private final GHOrganization organization;
+
+    private EnterpriseManagedSupport(GHOrganization organization) {
+        this.organization = organization;
+    }
+
+    Optional<GHIOException> filterException(final HttpException he, final String scenario) {
+        if (he.getResponseCode() == 400) {
+            final String responseMessage = he.getMessage();
+            try {
+                final GHError error = GitHubClient.getMappingObjectReader(this.organization.root())
+                        .forType(GHError.class)
+                        .readValue(responseMessage);
+                if (NOT_PART_OF_EXTERNALLY_MANAGED_ENTERPRISE_ERROR.equals(error.getMessage())) {
+                    return Optional.of(new GHNotExternallyManagedEnterpriseException(scenario, error, he));
+                } else if (TEAM_CANNOT_BE_EXTERNALLY_MANAGED_ERROR.equals(error.getMessage())) {
+                    return Optional.of(new GHTeamCannotBeExternallyManagedException(scenario, error, he));
+                }
+            } catch (final JsonProcessingException e) {
+                // We can ignore it
+                LOGGER.warning(() -> logUnexpectedFailure(e, responseMessage));
+            }
+        }
+        return Optional.empty();
+    }
+
+    Optional<GHException> filterException(final GHException e) {
+        if (e.getCause() instanceof HttpException) {
+            final HttpException he = (HttpException) e.getCause();
+            return filterException(he, COULD_NOT_RETRIEVE_ORGANIZATION_EXTERNAL_GROUPS)
+                    .map(translated -> new GHException(COULD_NOT_RETRIEVE_ORGANIZATION_EXTERNAL_GROUPS, translated));
+        }
+        return Optional.empty();
+    }
+
+    static EnterpriseManagedSupport forOrganization(final GHOrganization org) {
+        return new EnterpriseManagedSupport(org);
+    }
+
+    private static String logUnexpectedFailure(final JsonProcessingException exception, final String payload) {
+        final StringWriter sw = new StringWriter();
+        final PrintWriter pw = new PrintWriter(sw);
+        exception.printStackTrace(pw);
+        return String.format("Could not parse GitHub error response: '%s'. Full stacktrace follows:%n%s", payload, sw);
+    }
+
+}

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

@@ -0,0 +1,44 @@
+package org.kohsuke.github;
+
+/**
+ * Failure related to Enterprise Managed Users operations.
+ *
+ * @author Miguel Esteban Gutiérrez
+ */
+public class GHEnterpriseManagedUsersException extends GHIOException {
+
+    /**
+     * The serial version UID of the exception.
+     */
+    private static final long serialVersionUID = 1980051901L;
+
+    /**
+     * The error that caused the exception.
+     */
+    private final GHError error;
+
+    /**
+     * Instantiates a new exception.
+     *
+     * @param message
+     *            the message
+     * @param error
+     *            the error that caused the exception
+     * @param cause
+     *            the cause
+     */
+    public GHEnterpriseManagedUsersException(final String message, final GHError error, final Throwable cause) {
+        super(message, cause);
+        this.error = error;
+    }
+
+    /**
+     * Get the error that caused the exception.
+     *
+     * @return the error
+     */
+    public GHError getError() {
+        return error;
+    }
+
+}

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

@@ -0,0 +1,52 @@
+package org.kohsuke.github;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+import java.io.Serializable;
+import java.net.URL;
+
+/**
+ * Represents an error from GitHub.
+ *
+ * @author Miguel Esteban Gutiérrez
+ */
+public class GHError implements Serializable {
+
+    /**
+     * The serial version UID of the error
+     */
+    private static final long serialVersionUID = 2008071901;
+
+    /**
+     * The error message.
+     */
+    @SuppressFBWarnings(value = "UWF_UNWRITTEN_FIELD", justification = "Field comes from JSON deserialization")
+    private String message;
+
+    /**
+     * The URL to the documentation for the error.
+     */
+    @JsonProperty("documentation_url")
+    @SuppressFBWarnings(value = "UWF_UNWRITTEN_FIELD", justification = "Field comes from JSON deserialization")
+    private String documentation;
+
+    /**
+     * Get the error message.
+     *
+     * @return the message
+     */
+    public String getMessage() {
+        return message;
+    }
+
+    /**
+     * Get the URL to the documentation for the error.
+     *
+     * @return the url
+     */
+    public URL getDocumentationUrl() {
+        return GitHubClient.parseURL(documentation);
+    }
+
+}