Possible problem with migration diff with enums involved.

[tuhlmann]

Describe the bug
I think I see a bug with schema diffing (or migration) for my app using a Postgresql db:

I created an initial migration (using migrator.createInitialMigration()) from an existing schema (one that was updated through orm.getSchemaGenerator().updateSchema().

• The migration file was created fine but it was not logged to the migrations table because schemaExists returned false.
• To narrow down further I dropped all tables and created them by executing migrate up using the initial migration file. This worked fine.
• I then created a new migration. And this added some lines to the new migration file that it thinks are different between the current schema and the entities. I also ran this file. The next migration created would contain the same lines.
• The fields in that seem to get processed over and over are relatedType and mailType from queued-mail.entity.ts.

I attach the following files:

• the initial migration,
• the subsequent migration
• the entity and enum definitions in question.
• the ddl for this table as exported from my database. The table was created with the initial migration.

Let me know if I can debug anything to help sort this out! Thanks!

migration-issue.zip

To Reproduce
Steps to reproduce the behavior:
I'm sorry I don't have a reproduction repo yet. Please let me know if you need one.

Expected behavior

• Initial migration should have been created and logged
• Subsequent migration should not contain any model changes.

Additional context
Add any other context about the problem here.

Versions

Dependency	Version
node	12.18.3
typescript	4.0.2
mikro-orm	4.3.2
your-driver	postgres, using pg from mikro-orm

[tuhlmann]

I think I found one problem:

I changed the entity definition for the 2 enums from

  @Enum({ type: "MailType", items: () => MailType, default: MailType.Unknown })
  mailType: MailType // FIXME: set default value how?

  @Enum({
    type: "RelatedType",
    items: () => RelatedType,
    default: RelatedType.None,
    nullable: true,
  })
  relatedType?: RelatedType

to

  @Enum({ default: MailType.Unknown })
  mailType: MailType

  @Enum({ default: RelatedType.None, nullable: true })
  relatedType?: RelatedType

It seems that defining type and items for an int enum is not allowed?

Changing the enum definition does create them the same way they were (int2), but does not cause the newly created migration to contain schema changes over and over. A newly created migration is empty as it should be.

However, the initial migration created from the existing schema was still not logged to the migrations table. I'll try to figure out what causes this.

[tuhlmann]

I think I found why the initial migration doesn't get logged.
I added some comments to Migrator.validateInitialMigration and it seems the comparison between existing and expected is wrong.

I'm logging all the table names that are found in the database versus all those found in the schema. They can't match.
Here's the code with logging:

schema.getTables().forEach(table => {
            /* istanbul ignore next */
            const tableName = table.schema ? `${table.schema}.${table.name}` : table.name;
            console.log("found table ", tableName, expected.has(tableName));
            if (expected.has(tableName)) {
                exists.add(tableName);
            }
        });

Here's the names found in the DB (second are is expected.has(tableName)):

found table  public.attachment false
found table  public.attendee_event false
found table  public.email_preferences false
found table  public.event false
found table  public.event_documents false
found table  public.queued_mail false
found table  public.sent_mail false
found table  public.user false

Here's the set of expected entries:

Set {
  'attachment',
  'attendee_event',
  'email_preferences',
  'event',
  'queued_mail',
  'sent_mail',
  'user',
  'event_documents'
}

The set of existing entries is empty.

[B4nan]

Fixed in 4.3.3-dev.12