Expose Differential auxiliary fields in Conduit

Summary: Similar to D785 for Maniphest, expose auxiliary field values via
Conduit.
Test Plan: Ran revision.getinfo on a revision with aux fields, got them in the
response.
Reviewed By: jungejason
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, jungejason
Differential Revision: 802

src/applications/conduit/method/differential/getrevision/ConduitAPI_differential_getrevision_Method.php

@@ -78,6 +78,8 @@ class ConduitAPI_differential_getrevision_Method extends ConduitAPIMethod {
       );
     }
 
+    $auxiliary_fields = $this->loadAuxiliaryFields($revision);
+
     $dict = array(
       'id' => $revision->getID(),
       'phid' => $revision->getPHID(),
@@ -95,9 +97,26 @@ class ConduitAPI_differential_getrevision_Method extends ConduitAPIMethod {
       'reviewerPHIDs' => $reviewer_phids,
       'diffs' => $diff_dicts,
       'commits' => $commit_dicts,
+      'auxiliary' => $auxiliary_fields,
     );
 
     return $dict;
   }
 
+  private function loadAuxiliaryFields(DifferentialRevision $revision) {
+    $aux_fields = DifferentialFieldSelector::newSelector()
+      ->getFieldSpecifications();
+    foreach ($aux_fields as $key => $aux_field) {
+      if (!$aux_field->shouldAppearOnConduitView()) {
+        unset($aux_fields[$key]);
+      }
+    }
+
+    $aux_fields = DifferentialAuxiliaryField::loadFromStorage(
+      $revision,
+      $aux_fields);
+
+    return mpull($aux_fields, 'getValueForConduit', 'getStorageKey');
+  }
+
 }

src/applications/conduit/method/differential/getrevision/__init__.php

@@ -10,6 +10,8 @@ phutil_require_module('phabricator', 'applications/conduit/method/base');
 phutil_require_module('phabricator', 'applications/conduit/method/differential/getdiff');
 phutil_require_module('phabricator', 'applications/conduit/protocol/exception');
 phutil_require_module('phabricator', 'applications/differential/constants/revisionstatus');
+phutil_require_module('phabricator', 'applications/differential/field/selector/base');
+phutil_require_module('phabricator', 'applications/differential/storage/auxiliaryfield');
 phutil_require_module('phabricator', 'applications/differential/storage/revision');
 phutil_require_module('phabricator', 'applications/phid/handle/data');
 phutil_require_module('phabricator', 'infrastructure/env');

src/applications/differential/field/exception/incomplete/DifferentialFieldSpecificationIncompleteException.php

@@ -18,7 +18,7 @@
 
 class DifferentialFieldSpecificationIncompleteException extends Exception {
 
-  public function __construct(DifferentialFieldSpecification $spec, $claim) {
+  public function __construct(DifferentialFieldSpecification $spec) {
     $key = $spec->getStorageKey();
     $class = get_class($spec);
 

src/applications/differential/field/specification/base/DifferentialFieldSpecification.php

@@ -27,6 +27,7 @@
  * @task storage Field Storage
  * @task edit Extending the Revision Edit Interface
  * @task view Extending the Revision View Interface
+ * @task conduit Extending the Conduit View Interface
  */
 abstract class DifferentialFieldSpecification {
 
@@ -131,4 +132,21 @@ abstract class DifferentialFieldSpecification {
   }
 
 
+/* -(  Extending the Conduit Interface  )------------------------------------ */
+
+
+  /**
+   * @task conduit
+   */
+  public function shouldAppearOnConduitView() {
+    return false;
+  }
+
+  /**
+   * @task conduit
+   */
+  public function getValueForConduit() {
+    throw new DifferentialFieldSpecificationIncompleteException($this);
+  }
+
 }

src/applications/differential/field/specification/blamerev/DifferentialBlameRevisionFieldSpecification.php

@@ -70,4 +70,12 @@ final class DifferentialBlameRevisionFieldSpecification
     return phutil_escape_html($this->value);
   }
 
+  public function shouldAppearOnConduitView() {
+    return true;
+  }
+
+  public function getValueForConduit() {
+    return $this->value;
+  }
+
 }

src/applications/differential/field/specification/revertplan/DifferentialRevertPlanFieldSpecification.php

@@ -70,4 +70,12 @@ final class DifferentialRevertPlanFieldSpecification
     return phutil_escape_html($this->value);
   }
 
+  public function shouldAppearOnConduitView() {
+    return true;
+  }
+
+  public function getValueForConduit() {
+    return $this->value;
+  }
+
 }