Relations do not render primary key column values correctly when transformers present

[blueskymonster]

Issue Description

When an primary key column has one or more transformers specified, relations fail to render their sql properly because the do not run the entity value through the transformer.

Expected Behavior

When a relation is loaded, the transformed value present in the entity should be run through the transformer to function(s) before it is passed into the SQL.

As an example, here's a contrived transformer that takes integer database columns and turns them into strings in typescript that have double quotes around them. While obviously not a reasonable use case, there are plenty of reasons why someone may want to transform an Id column in other ways.

const WrappedIntTransformer = {
  from: (value: number) => `"${value}"`,
  to: (value: string | undefined | null) => value ? parseInt(value.slice(1, value.length - 1)) : null,
}

@Entity()
export class User {
  @PrimaryColumn({ type: "int", transformer: WrappedIntTransformer, nullable: false })
  id: string;

  @OneToMany(() => Photo, (photo) => photo.user)
  photos: Promise<Photo[]>;
}

@Entity()
export class Photo {
  @PrimaryColumn({ type: "int", transformer: WrappedIntTransformer, nullable: false })
  id: string;

  @Column({ type: "text" })
  url: string;

  @Column({ type: "int", transformer: WrappedIntTransformer, nullable: false })
  userId: string;

  @ManyToOne(() => User, (user) => user.photos)
  @JoinColumn({ name: "userId", referencedColumnName: "id" })
  user: Promise<User>;
}

Then I expect to be able to call await user.photos and get something like this:

query: SELECT "photos"."id" AS "photos_id", "photos"."url" AS "photos_url", "photos"."userId" AS "photos_userId" FROM "photo" "photos" WHERE "photos"."userId" IN (?) -- PARAMETERS: [1]

Actual Behavior

When a relation is loaded, the transformed value present in the entity is used directly in the SQL without being "untransformed".

In the above example, running await user.photos actually generates this:

query: SELECT "photos"."id" AS "photos_id", "photos"."url" AS "photos_url", "photos"."userId" AS "photos_userId" FROM "photo" "photos" WHERE "photos"."userId" IN (?) -- PARAMETERS: ["\"1\""]

The value for user.id has not been un-transformed before shipping it back to sql.

Steps to Reproduce

1. Clone my example repo
2. npm install
3. npm start
4. Notice the final printed query with its incorrect parameters.

My Environment

Dependency	Version
Operating System	debian
Node.js version	12.21.0
Typescript version	4.5.5
TypeORM version	0.2.43

Additional Context

I believe I have identified how to fix the issue. Simply adding a second parameter true to all calls of getEntityValue in RelationLoader.ts. i.e. getEntityValue(entity, true) instead of getEntityValue(entity).

Relevant Database Driver(s)

I have manually confirmed this against postgresql and sqlite, but from my shallow understanding of the codebase, I think this likely affects all databases.

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

I will be opening a PR shortly. 😄

• ✅ 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.