Pleasing code climate, abstracting duplicated code

lib/associations/belongs-to.js

@@ -65,9 +65,7 @@ module.exports = (function() {
     // Sync attributes and setters/getters to DAO prototype
     this.source.refreshAttributes();
 
-    if (this.source.rawAttributes.hasOwnProperty(this.as)) {
-      throw new Error("Naming collision between attribute '" + this.as + "' and association '" + this.as + "' on model " + this.source.name + '. To remedy this, change either foreignKey or as in your association definition');
-    }
+    Helpers.checkNamingCollision(this);
 
     return this;
   };

lib/associations/has-many.js

@@ -261,9 +261,7 @@ module.exports = (function() {
     this.target.refreshAttributes();
     this.source.refreshAttributes();
 
-    if (this.source.rawAttributes.hasOwnProperty(this.as)) {
-      throw new Error("Naming collision between attribute '" + this.as + "' and association '" + this.as + "' on model " + this.source.name + '. To remedy this, change either foreignKey or as in your association definition');
-    }
+    Helpers.checkNamingCollision(this);
 
     return this;
   };

lib/associations/has-one.js

@@ -67,9 +67,7 @@ module.exports = (function() {
     // Sync attributes and setters/getters to DAO prototype
     this.target.refreshAttributes();
 
-    if (this.source.rawAttributes.hasOwnProperty(this.as)) {
-      throw new Error("Naming collision between attribute '" + this.as + "' and association '" + this.as + "' on model " + this.source.name + '. To remedy this, change either foreignKey or as in your association definition');
-    }
+    Helpers.checkNamingCollision(this);
 
     return this;
   };

lib/associations/helpers.js

@@ -3,6 +3,11 @@
 var Utils = require('./../utils');
 
 module.exports = {
+  checkNamingCollision: function (assocition) {
+    if (assocition.source.rawAttributes.hasOwnProperty(assocition.as)) {
+      throw new Error("Naming collision between attribute '" + assocition.as + "' and association '" + assocition.as + "' on model " + assocition.source.name + '. To remedy this, change either foreignKey or as in your association definition');
+    }
+  },
 
   addForeignKeyConstraints: function(newAttribute, source, target, options) {
     // FK constraints are opt-in: users must either set `foreignKeyConstraints`

lib/associations/mixin.js

@@ -93,6 +93,31 @@ var Utils = require('./../utils')
  */
 var Mixin = module.exports = function() {};
 
+// The logic for hasOne and belongsTo is exactly the same
+var singleLinked = function (Type) {
+  return function(targetModel, options) {
+    if (!(targetModel instanceof this.sequelize.Model)) {
+      throw new Error(this.name + "." + Utils._.lowercaseFirst(Type.toString()) + " called with something that's not an instance of Sequelize.Model");
+    }
+
+    var sourceModel = this;
+
+    // Since this is a mixin, we'll need a unique variable name for hooks (since Model will override our hooks option)
+    options = options || {};
+    options.hooks = options.hooks === undefined ? false : Boolean(options.hooks);
+    options.useHooks = options.hooks;
+
+    // the id is in the foreign table
+    var association = new Type(sourceModel, targetModel, Utils._.extend(options, sourceModel.options));
+    sourceModel.associations[association.associationAccessor] = association.injectAttributes();
+
+    association.injectGetter(sourceModel.Instance.prototype);
+    association.injectSetter(sourceModel.Instance.prototype);
+    association.injectCreator(sourceModel.Instance.prototype);
+
+    return association;
+  };
+};
 /**
  * Creates an association between this (the source) and the provided target. The foreign key is added on the target.
  *
@@ -115,28 +140,7 @@ var Mixin = module.exports = function() {};
  * @param {string}          [options.onUpdate='CASCADE']
  * @param {boolean}         [options.constraints=true] Should on update and on delete constraints be enabled on the foreign key.
  */
-Mixin.hasOne = function(targetModel, options) {
-  if (!(targetModel instanceof this.sequelize.Model)) {
-    throw new Error(this.name + ".hasOne called with something that's not an instance of Sequelize.Model");
-  }
-
-  var sourceModel = this;
-
-  // Since this is a mixin, we'll need a unique variable name for hooks (since Model will override our hooks option)
-  options = options || {};
-  options.hooks = options.hooks === undefined ? false : Boolean(options.hooks);
-  options.useHooks = options.hooks;
-
-  // the id is in the foreign table
-  var association = new HasOne(sourceModel, targetModel, Utils._.extend(options, sourceModel.options));
-  sourceModel.associations[association.associationAccessor] = association.injectAttributes();
-
-  association.injectGetter(sourceModel.Instance.prototype);
-  association.injectSetter(sourceModel.Instance.prototype);
-  association.injectCreator(sourceModel.Instance.prototype);
-
-  return association;
-};
+Mixin.hasOne = singleLinked(HasOne);
 
 /**
  * Creates an association between this (the source) and the provided target. The foreign key is added on the source.
@@ -160,28 +164,7 @@ Mixin.hasOne = function(targetModel, options) {
  * @param {string}          [options.onUpdate='CASCADE']
  * @param {boolean}         [options.constraints=true] Should on update and on delete constraints be enabled on the foreign key.
  */
-Mixin.belongsTo = function(targetModel, options) {
-  if (!(targetModel instanceof this.sequelize.Model)) {
-    throw new Error(this.name + ".belongsTo called with something that's not an instance of Sequelize.Model");
-  }
-
-  var sourceModel = this;
-
-  // Since this is a mixin, we'll need a unique variable name for hooks (since Model will override our hooks option)
-  options = options || {};
-  options.hooks = options.hooks === undefined ? false : Boolean(options.hooks);
-  options.useHooks = options.hooks;
-
-  // the id is in this table
-  var association = new BelongsTo(sourceModel, targetModel, Utils._.extend(options, sourceModel.options));
-  sourceModel.associations[association.associationAccessor] = association.injectAttributes();
-
-  association.injectGetter(sourceModel.Instance.prototype);
-  association.injectSetter(sourceModel.Instance.prototype);
-  association.injectCreator(sourceModel.Instance.prototype);
-
-  return association;
-};
+Mixin.belongsTo = singleLinked(BelongsTo);
 
 /**
  * Create an association that is either 1:m or n:m.

lib/dialects/mysql/query-generator.js

@@ -198,7 +198,7 @@ module.exports = (function() {
     },
 
     deleteQuery: function(tableName, where, options) {
-      options = options ||  {};
+      options = options || {};
 
       var table = this.quoteTable(tableName);
       if (options.truncate === true) {

lib/dialects/sqlite/query-generator.js

@@ -206,7 +206,7 @@ module.exports = (function() {
     },
 
     deleteQuery: function(tableName, where, options) {
-      options = options || {};
+      options = options || {};
 
       var query = "DELETE FROM <%= table %> WHERE <%= where %>";
       var replacements = {

lib/promise.js

@@ -152,7 +152,7 @@ SequelizePromise.prototype.proxy = function(promise, options) {
   options = Utils._.extend({
     events: proxyEventKeys,
     skipEvents: []
-  }, options ||  {});
+  }, options || {});
 
   options.events = Utils._.difference(options.events, options.skipEvents);
 

lib/transaction.js

@@ -9,7 +9,7 @@ var Utils = require('./utils')
  * To run a query under a transaction, you should pass the transaction in the options object.
  * @class Transaction
  */
-var Transaction = module.exports = function(sequelize, options) {
+var Transaction = module.exports = function(sequelize, options) {
   this.sequelize = sequelize;
   this.options = Utils._.extend({
     autocommit: true,

lib/utils.js

@@ -16,6 +16,9 @@ var Utils = module.exports = {
     _.mixin(_s.exports());
     _.mixin({
       includes: _s.include,
+      lowercaseFirst: function (s) {
+        return s[0].toLowerCase() + s.slice(1);
+      },
       camelizeIf: function(string, condition) {
         var result = string;