Prevent empty string in Entity column in TypeOrm

Question

I want to prevent the insertion of an empty string for a string column.

Aside: Yes I can do the constraint in the DB, and I will do that.

I would like it so if an empty string is assigned to that property, typeorm will automatically null it.

For example, I imagine something like:

@Entity()
class Foo {
  @Column()
  @NoEmptyString()
  bar: string;
}

and then if someone were to:

const foo = new Foo();
foo.bar = '';
repository.save(foo);

then foo would be inserted with NULL as the value of bar.

TypeORM also has validations but they actually seem to all come from class-validator and need to be called manually.

Answer 1

@Entity()
class Foo {
  @Column()
  @NoEmptyString()
  bar: string;

  @BeforeInsert()
  @BeforeUpdate()
  replaceEmptyStringAsNull() {
    if (this.bar === '') {
      this.bar = null;
    }
  }
}