microsoft / microsoft/TypeScript

super() typed as returning void

Open
#59,959 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Awaiting More Feedback Suggestion
Dominant language
Go
Stars
111k
Forks
14.3k
Avg merge
2d 4h
Merged PRs (30d)
132

Description

💻 Code
class Parent {}

class Child extends Parent {
	constructor() {
		super().func();
	}

	func() {

	}
}
🙁 Actual behavior

super() in constructor return the object but TS assumes it returns void:

image

🙂 Expected behavior

super() should return the object.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the TypeScript example in the issue and inspect how the type checker handles super() in a derived constructor. Compare the inferred return type with JavaScript runtime behavior, then add or update coverage for super().func() so the completed change accepts the example without introducing incorrect constructor behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, typescript
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.