niieani/typescript-vs-flowtype

Document contravariance and covariance

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#66 opened on Nov 22, 2019

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Description

Flow supports contravariance (-), TypeScript doesn't.

Also, TypeScript doesn't support covariance (+) on all its types, but just some of them.

Contributor guide

Research direction
Investigate how contravariance and covariance are handled in TypeScript and Flowtype, then update the documentation in the repository.
Tech stack
typescript
Domain
developer experience
Issue type
Documentation
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
1
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
TypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
90