fix(schema): skip changes of enum items on enum arrays

They are not enforced on schema level, so it does not make sense to compare the items.

Related #476

packages/knex/src/schema/SchemaComparator.ts

@@ -1,5 +1,14 @@
 import { inspect } from 'util';
-import { BooleanType, DateTimeType, JsonType, parseJsonSafe, Utils, type Dictionary, type EntityProperty } from '@mikro-orm/core';
+import {
+  ArrayType,
+  BooleanType,
+  DateTimeType,
+  JsonType,
+  parseJsonSafe,
+  Utils,
+  type Dictionary,
+  type EntityProperty,
+} from '@mikro-orm/core';
 import type { Check, Column, ForeignKey, Index, SchemaDifference, TableDifference } from '../typings';
 import type { DatabaseSchema } from './DatabaseSchema';
 import type { DatabaseTable } from './DatabaseTable';
@@ -443,7 +452,11 @@ export class SchemaComparator {
       changedProperties.add('comment');
     }
 
-    if (this.diffEnumItems(column1.enumItems, column2.enumItems)) {
+    if (
+      !(column1.mappedType instanceof ArrayType) &&
+      !(column2.mappedType instanceof ArrayType) &&
+      this.diffEnumItems(column1.enumItems, column2.enumItems)
+    ) {
       log(`'enumItems' changed for column ${tableName}.${column1.name}`, { column1, column2 });
       changedProperties.add('enumItems');
     }

tests/features/schema-generator/enum-array.postgres.test.ts

@@ -0,0 +1,36 @@
+import { Entity, Enum, PrimaryKey } from '@mikro-orm/core';
+import { MikroORM } from '@mikro-orm/postgresql';
+
+enum AdminPermission {
+  ROOT = 'ROOT',
+  ACCESS = 'ACCESS',
+}
+
+@Entity()
+class Admin {
+
+  @PrimaryKey()
+  id!: number;
+
+  @Enum({
+    items: () => AdminPermission,
+    array: true,
+    default: [],
+  })
+  permissions: AdminPermission[] = [];
+
+}
+
+test('enum array diffing', async () => {
+  const orm = await MikroORM.init({
+    entities: [Admin],
+    dbName: `mikro_orm_test_enum_array_diffing`,
+  });
+
+  await orm.schema.refreshDatabase();
+
+  const diff = await orm.schema.getUpdateSchemaSQL({ wrap: false });
+  expect(diff).toBe('');
+
+  await orm.close(true);
+});