ARTICLE AD BOX
I'm building a MERN stack project using the repository pattern architecture. I understand what a DTO is, and I'm already using several DTOs in my project.
During a code review, a developer suggested that I should use DTO mappers. While researching this topic, I found that DTO mappers seem to be related to transforming or mapping data from one structure to another (for example, renaming fields or reshaping objects). I also noticed that there are some libraries/packages that help with this.
The problem is that I don't clearly understand why DTO mappers are needed, or where exactly they should be used in a project. Right now I'm just creating DTOs and using it were ever necessary. This is something i found while researching.
interface UserInputDTO { userId: number; fullName: string; userEmail: string; } interface UserOutputDTO { id: number; name: string; email: string; } function mapUserInputToOutput(input: UserInputDTO): UserOutputDTO { return { id: input.userId, name: input.fullName, email: input.userEmail }; } const input: UserInputDTO = { userId: 1, fullName: "John Doe", userEmail: "[email protected]" }; const output = mapUserInputToOutput(input); console.log(output);So I have a few questions:
What is the actual purpose of a DTO mapper?
Where do we use the DTO mapper?
When should a DTO mapper be used instead of manually creating DTO objects?
If a project has many DTOs, do developers normally create a separate mapper function for every transformation, or is there a better pattern to manage this?
If you guys have any good article or videos please share it would be useful.
