Unnecessary migration generated for enum column when using MySQL/Aurora Data API after upgrade from v0.2.31 to v0.2.37

[coyoteecd]

Issue Description

I am rebasing my typeorm fork from v0.2.31 to latest master (~v0.2.37) and trying to use it in our project.
One of the issues I have is that after upgrade, generating migrations over an up-to-date existing database a rather high amount of unnecessary changes. One of the issues I could pinpoint is that all enum columns generate ALTER TABLE statements.

I believe the issue is in BaseQueryRunner here:

typeorm/src/query-runner/BaseQueryRunner.ts

Line 343 in a868078

|| oldColumn.enum !== newColumn.enum;

The column enum property is documented to have all the enum values, and indeed when debugging both old and new column definitions have enum = array of enum (string) values. So we're comparing array references there. This code is broken for quite a while, I suspect the issue appeared due to some object cloning which made the array references be different.

Expected Behavior

No migrations generated

Actual Behavior

Unnecessary ALTER TABLE ... CHANGE column is generated.
Applying the migration does not solve the problem, generating a new migration afterwards keeps generating the same script.

Steps to Reproduce

Here's an example entity:

enum Status {
  First = 'First',
  Second = 'Second'
}

@Entity
export class User {
  @Column({ type: 'enum', enum: Status, default: Status.First })
  public status: Status;
}

Generating migrations produces the following:

export class test31631015251611 implements MigrationInterface {
  name = 'test31631015251611';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`ALTER TABLE \`user\` CHANGE \`status\` \`status\` enum ('First', 'Second') NOT NULL DEFAULT 'First'`);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`ALTER TABLE \`user\` CHANGE \`status\` \`status\` enum ('First', 'Second') NOT NULL DEFAULT 'First'`);
  }
}

My Environment

Dependency	Version
Operating System
Node.js version	v14.16.0
Typescript version	4.4.2
TypeORM version	0.2.37

Additional Context

Relevant Database Driver(s)

DB Type	Reproducible
aurora-data-api	yes
aurora-data-api-pg	no
better-sqlite3	no
cockroachdb	no
cordova	no
expo	no
mongodb	no
mysql	probably
nativescript	no
oracle	no
postgres	no
react-native	no
sap	no
sqlite	no
sqlite-abstract	no
sqljs	no
sqlserver	no

Are you willing to resolve this issue by submitting a Pull Request?

• ✅ Yes, I have the time, and I know how to start.
• ✖️ Yes, I have the time, but I don't know how to start. I would need guidance.
• ✖️ No, I don’t have the time, but I can support (using donations) development.
• ✖️ No, I don’t have the time and I’m okay to wait for the community / maintainers to resolve this issue.