fix(postgres): addColumn support ARRAY(ENUM) (#12259)

lib/dialects/postgres/query-generator.js

@@ -244,17 +244,19 @@ class PostgresQueryGenerator extends AbstractQueryGenerator {
     return super.handleSequelizeMethod.call(this, smth, tableName, factory, options, prepend);
   }
 
-  addColumnQuery(table, key, dataType) {
-
-    const dbDataType = this.attributeToSQL(dataType, { context: 'addColumn', table, key });
+  addColumnQuery(table, key, attribute) {
+    const dbDataType = this.attributeToSQL(attribute, { context: 'addColumn', table, key });
+    const dataType = attribute.type || attribute;
     const definition = this.dataTypeMapping(table, key, dbDataType);
     const quotedKey = this.quoteIdentifier(key);
     const quotedTable = this.quoteTable(this.extractTableDetails(table));
 
     let query = `ALTER TABLE ${quotedTable} ADD COLUMN ${quotedKey} ${definition};`;
 
-    if (dataType.type && dataType.type instanceof DataTypes.ENUM || dataType instanceof DataTypes.ENUM) {
+    if (dataType instanceof DataTypes.ENUM) {
       query = this.pgEnum(table, key, dataType) + query;
+    } else if (dataType.type && dataType.type instanceof DataTypes.ENUM) {
+      query = this.pgEnum(table, key, dataType.type) + query;
     }
 
     return query;

test/integration/query-interface.test.js

@@ -380,6 +380,23 @@ describe(Support.getTestDialectTeaser('QueryInterface'), () => {
         values: ['value1', 'value2', 'value3']
       });
     });
+
+    if (dialect === 'postgres') {
+      it('should be able to add a column of type of array of enums', async function() {
+        await this.queryInterface.addColumn('users', 'tags', {
+          allowNull: false,
+          type: Sequelize.ARRAY(Sequelize.ENUM(
+            'Value1',
+            'Value2',
+            'Value3'
+          ))
+        });
+        const result = await this.queryInterface.describeTable('users');
+        expect(result).to.have.property('tags');
+        expect(result.tags.type).to.equal('ARRAY');
+        expect(result.tags.allowNull).to.be.false;
+      });
+    }
   });
 
   describe('describeForeignKeys', () => {