feat(index): tests and new where query generator for postgres partial indexes

changelog.md

@@ -3,6 +3,7 @@
 - [BUG] instance.removeAssociation(s) do not fire the select query twice anymore
 - [BUG] Error messages thrown by the db in languages other than english do not crash the app anymore (mysql, mariadb and postgres only) [#3567](https://github.com/sequelize/sequelize/pull/3567)
 - [FEATURE] All querys can be logged individually by inserting `logging: fn` in the query option.
+- [FEATURE] Partial index support for Postgres with `index.where`
 - [DEPRECATED] The query-chainer is deprecated and will be removed in version 2.2. Please use promises instead.
 - [REMOVED] Events are no longer supported.
 

lib/dialects/abstract/query-generator.js

@@ -539,11 +539,7 @@ module.exports = (function() {
       }
 
       if (options.where) {
-        if (Array.isArray(options.where)) {
-          options.where = Utils.format(options.where);
-        } else if (!Utils._.isString(options.where)) {
-          delete options.where
-        }
+        options.where = this.whereQuery(options.where);
       }
 
       return Utils._.compact([
@@ -557,7 +553,7 @@ module.exports = (function() {
         this._dialect.supports.index.using === 2 && options.using ? 'USING ' + options.using : '',
         '(' + fieldsSql.join(', ') + (options.operator ? ' '+options.operator : '') + ')',
         (this._dialect.supports.index.parser && options.parser ? 'WITH PARSER ' + options.parser : undefined),
-        (this._dialect.supports.index.where && options.where ? 'WHERE ' + options.where : undefined)
+        (this._dialect.supports.index.where && options.where ? options.where : undefined)
       ]).join(' ');
     },
 

test/unit/sql/index.test.js

@@ -55,6 +55,33 @@ suite(Support.getTestDialectTeaser('SQL'), function() {
       });
     }
 
+    if (current.dialect.supports.index.using === 2) {
+      test('WHERE', function () {
+        expectsql(sql.addIndexQuery('table', {
+          fields: ['type'],
+          where: {
+            type: 'public'
+          }
+        }), {
+          postgres: 'CREATE INDEX "table_type" ON "table" ("type") WHERE "type" = \'public\''
+        });
+
+        expectsql(sql.addIndexQuery('table', {
+          fields: ['type'],
+          where: {
+            type: {
+              $or: [
+                'group',
+                'private'
+              ]
+            }
+          }
+        }), {
+          postgres: 'CREATE INDEX "table_type" ON "table" ("type") WHERE ("type" = \'group\' OR "type" = \'private\')'
+        });
+      });
+    }
+
     if (current.dialect.supports.JSON) {
       test('operator', function () {
         expectsql(sql.addIndexQuery('table', {