code minify causes "Entity metadata for e#activities was not found"

Issue type:

[ ] question [x] bug report [ ] feature request [ ] documentation issue

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [ ] mysql / mariadb [ ] oracle [ ] postgres [ ] cockroachdb [x] sqlite [ ] sqljs [ ] react-native [ ] expo

TypeORM version:

[ ] latest [ ] @next [x ] 0.2.18

Steps to reproduce or a small repository showing the problem:

@Entity('space')
export default class Space {
  @PrimaryColumn()
  spaceId: string;

  @Column()
  spaceName: string;

  @OneToMany('activity', 'space')
  activities: Promise<Activity[]>
}

@Entity('activity')
export default class Activity {
  @PrimaryColumn()
  activityId: string;

  @Column('text')
  text: string;

  @ManyToOne('space', 'activities')
  @JoinColumn({ name: 'spaceId' })
  space: Promise<Space>
}

In my project, code minifing (uglifyjs) is required, it will convert classnames like ‘Space’ into single characters like ‘e’. The problem occurs here in EntityMetadataBuilder.ts:L649.

IMHO m.givenTableName is not honored but should. Therefore we can use uglifyjs without breaking typeorm.

[bigLucas]

Hello guys, I spent a week trying to solve a problem like this. So I solved this problem, just changed my repository method that saves the entity. I used repository.save (entity) and always failed with cyclic dependency.

After switching to

repository.createQueryBuilder()
    .insert()
    .into(TABLE_NAME)
    .values(entity)
    .execute();

This error has been cleared. I really recommend trying to change the repository method, because the save() method waits for the full entity set and createQueryBuilder() takes the entity values and turns them into string values, making a normal query.

I was using serverless and webpack. Typeorm does not work well with webpack.

[cvdat2097]

My Solution

Just declare unique static property name for each of your classes

How does this fix the “Cyclic dependency” error of minified code?

This error derives from function SubjectTopoligicalSorter.toposort() which requires unique targetNames. Those targetNames are extracted from the special property Function.name of our classes (yes, classes are functions in JS). However, after the minification process, the class names (function names) are changed to something like “t”, “e”,… which can be duplicated. Therefore, manually assign unique name values for our classes solved the problem.

Bonus Solution

You can configure the bundler not to touch the function names to fix this. However, I personally don’t prefer this method. Take my metro.config.js file for example (I’m using typeorm in React Native project)

module.exports = {
  transformer: {
    minifierConfig: {
      keep_fnames: true, // To avoid cyclic dependency "t" error of typeorm in release build
    },
  },
};