readonly-keyword fixer adds the readonly modifier in the wrong place for decorated class properties

[clarkdave]

This requires experimentalDecorators: true in tsconfig.

---

Given the following TypeScript:

class MyEntity {
  @PrimaryGeneratedColumn() id!: number

  @Column('text') name!: number
}

The readonly-keyword fixer outputs:

class MyEntity {
  readonly @PrimaryGeneratedColumn() id!: number

  readonly @Column('text') name!: number
}

This is invalid TypeScript syntax and fails to compile. The correct syntax for decorators and the readonly modifier should be:

class MyEntity {
  @PrimaryGeneratedColumn() readonly id!: number

  @Column('text') readonly name!: number
}

---

Other notes

• The tslint rule does detect the readonly modifier if it is already present in the correct place
• Applying the quick fix again will continue prepending readonly to the line, e.g. readonly readonly readonly readonly @Column('text') name!: number

[jonaskello]

This seems like an obvious bug. If someone would like to attempt a PR that would be much appreciated, otherwise I will fix it as soon as time allows.