bug(indexes) Set unique: true when type = UNIQUE. Closes #5351

changelog.md

 # Future
 - [ADDED] `beforeCount` hook [#5209](https://github.com/sequelize/sequelize/pull/5209)
 - [ADDED] `validationFailed` hook [#1626](https://github.com/sequelize/sequelize/issues/1626)
+- [FIXED] Mark index as `unique: true` when `type: 'UNIQUE'`. Fixes [#5351](https://github.com/sequelize/sequelize/issues/5351)
 
 # 3.19.3
 - [FIXED] `updatedAt` and `createdAt` values are now set before validation [#5367](https://github.com/sequelize/sequelize/pull/5367)

lib/dialects/abstract/query-generator.js

@@ -662,15 +662,7 @@ var QueryGenerator = {
       options = this.nameIndexes([options], options.prefix)[0];
     }
 
-    options = Utils._.defaults(options, {
-      type: '',
-      parser: null
-    });
-
-    if (options.type.toLowerCase() === 'unique') {
-      options.unique = true;
-      delete options.type;
-    }
+    options = Model.prototype.$conformIndex(options);
 
     if (!this._dialect.supports.index.type) {
       delete options.type;
@@ -686,8 +678,6 @@ var QueryGenerator = {
       tableName = this.quoteTable(tableName);
     }
 
-
-
     var concurrently = this._dialect.supports.index.concurrently && options.concurrently ? 'CONCURRENTLY' : undefined
       , ind;
     if (this._dialect.supports.indexViaAlter) {

lib/model.js

@@ -728,12 +728,27 @@ Model.prototype.init = function(modelManager) {
     }
   }.bind(this));
 
+  this.options.indexes = this.options.indexes.map(this.$conformIndex);
+
   this.Instance.prototype.$Model =
   this.Instance.prototype.Model = this;
 
   return this;
 };
 
+Model.prototype.$conformIndex = function (index) {
+  index = _.defaults(index, {
+    type: '',
+    parser: null
+  });
+
+  if (index.type && index.type.toLowerCase() === 'unique') {
+    index.unique = true;
+    delete index.type;
+  }
+  return index;
+};
+
 Model.prototype.refreshAttributes = function() {
   var self = this
     , attributeManipulation = {};

test/unit/model/indexes.test.js

@@ -23,5 +23,21 @@ describe(Support.getTestDialectTeaser('Model'), function() {
       expect(Model.options.indexes[0].fields).to.eql(['data']);
       expect(Model.options.indexes[0].using).to.equal('gin');
     });
+
+    it('should set the unique property when type is unique', function () {
+      var Model = current.define('m', {}, {
+        indexes: [
+          {
+            type: 'unique'
+          },
+          {
+            type: 'UNIQUE'
+          }
+        ]
+      });
+
+      expect(Model.options.indexes[0].unique).to.eql(true);
+      expect(Model.options.indexes[1].unique).to.eql(true);
+    });
   });
-});
\ No newline at end of file
+});