feat(postgres): drop enum support (#9641)

lib/query-interface.js

@@ -293,6 +293,27 @@ class QueryInterface {
   }
 
   /**
+   * Drop specified enum from database, Postgres Only
+   * @param {String} [enumName]  Enum name to drop
+   * @param {Object} options Query options
+   *
+   * @return {Promise}
+   * @private
+   */
+  dropEnum(enumName, options) {
+    if (this.sequelize.getDialect() !== 'postgres') {
+      return Promise.resolve();
+    }
+
+    options = options || {};
+
+    return this.sequelize.query(
+      this.QueryGenerator.pgEnumDrop(null, null, this.QueryGenerator.pgEscapeAndQuote(enumName)),
+      _.assign({}, options, { raw: true })
+    );
+  }
+
+  /**
    * Drop all enums from database, Postgres Only
    *
    * @param {Object} options Query options

test/integration/query-interface/dropEnum.test.js

+'use strict';
+
+const chai = require('chai');
+const expect = chai.expect;
+const Support = require(__dirname + '/../support');
+const DataTypes = require(__dirname + '/../../../lib/data-types');
+const dialect = Support.getTestDialect();
+
+describe(Support.getTestDialectTeaser('QueryInterface'), () => {
+  beforeEach(function() {
+    this.sequelize.options.quoteIdenifiers = true;
+    this.queryInterface = this.sequelize.getQueryInterface();
+  });
+
+  afterEach(function() {
+    return this.sequelize.dropAllSchemas();
+  });
+
+  describe('dropEnum', () => {
+    beforeEach(function() {
+      return this.queryInterface.createTable('menus',  {
+        structuretype: {
+          type: DataTypes.ENUM('menus', 'submenu', 'routine'),
+          allowNull: true
+        },
+        sequence: {
+          type: DataTypes.INTEGER,
+          allowNull: true
+        },
+        name: {
+          type: DataTypes.STRING,
+          allowNull: true
+        }
+      });
+    });
+
+    if (dialect === 'postgres') {
+      it('should be able to drop the specified enum', function() {
+        return this.queryInterface.removeColumn('menus', 'structuretype').bind(this).then(function() {
+          return this.queryInterface.pgListEnums('menus');
+        }).then(enumList => {
+          expect(enumList).to.have.lengthOf(1);
+          expect(enumList[0]).to.have.property('enum_name').and.to.equal('enum_menus_structuretype');
+        }).then(() => {
+          return this.queryInterface.dropEnum('enum_menus_structuretype');
+        }).then(() => {
+          return this.queryInterface.pgListEnums('menus');
+        }).then(enumList => {
+          expect(enumList).to.be.an('array');
+          expect(enumList).to.have.lengthOf(0);
+        });
+      });
+    }
+  });
+});