Merge pull request #394 from clarkbw/hasManyThroughKeyThrough

hasMany through doesn't set the through key value

lib/relation-definition.js

@@ -6,6 +6,7 @@ var util = require('util');
 var async = require('async');
 var utils = require('./utils');
 var i8n = require('inflection');
+var _ = require('lodash');
 var defineScope = require('./scope.js').defineScope;
 var mergeQuery = utils.mergeQuery;
 var ModelBaseClass = require('./model.js');
@@ -468,20 +469,14 @@ util.inherits(ReferencesMany, Relation);
 /*!
  * Find the relation by foreign key
  * @param {*} foreignKey The foreign key
- * @returns {Object} The relation object
+ * @returns {Array} The array of matching relation objects
  */
 function findBelongsTo(modelFrom, modelTo, keyTo) {
-  var relations = modelFrom.relations;
-  var keys = Object.keys(relations);
-  for (var k = 0; k < keys.length; k++) {
-    var rel = relations[keys[k]];
-    if (rel.type === RelationTypes.belongsTo &&
-      rel.modelTo === modelTo &&
-      (keyTo === undefined || rel.keyTo === keyTo)) {
-      return rel.keyFrom;
-    }
-  }
-  return null;
+  return _.pluck(_.filter(modelFrom.relations, function (rel) {
+    return (rel.type === RelationTypes.belongsTo &&
+            rel.modelTo === modelTo &&
+            (keyTo === undefined || rel.keyTo === keyTo));
+  }), 'keyFrom');
 }
 
 /*!
@@ -833,10 +828,12 @@ var throughKeys = function(definition) {
     } else {
       var fk2 = definition.keyThrough;
     }
+  } else if (definition.modelFrom === definition.modelTo) {
+    return findBelongsTo(modelThrough, definition.modelTo, pk2);
   } else {
     var fk1 = findBelongsTo(modelThrough, definition.modelFrom,
-      definition.keyFrom);
-    var fk2 = findBelongsTo(modelThrough, definition.modelTo, pk2);
+                            definition.keyFrom)[0];
+    var fk2 = findBelongsTo(modelThrough, definition.modelTo, pk2)[0];
   }
   return [fk1, fk2];
 }

package.json

@@ -30,6 +30,7 @@
     "async": "^0.9.0",
     "debug": "^2.1.1",
     "inflection": "^1.6.0",
+    "lodash": "~3.0.1",
     "loopback-connector": "1.x",
     "qs": "^2.3.3",
     "traverse": "^0.6.6"

test/relations.test.js

@@ -690,6 +690,18 @@ describe('relations', function () {
       });
     });
 
+    it('should set the keyThrough and the foreignKey', function (done) {
+      var user = new User({id: 1});
+      var user2 = new User({id: 2});
+      user.following.add(user2, function (err, f) {
+        should.not.exist(err);
+        should.exist(f);
+        f.followeeId.should.equal(user2.id);
+        f.followerId.should.equal(user.id);
+        done();
+      });
+    });
+
     it('can determine the collect via keyThrough for each side', function () {
       var user = new User({id: 1});
       var scope1 = user.followers._scope;