Flow now lets you define a function that encodes a type predicate over its…
Conditional types allow you to choose between two different output types by inspecting an input type. The…
To make it easier for new users to get started with Flow, we’re updating our type casting…
We’ve refreshed our documentation, and added the ability to configure options and lints in Try Flow!
Tuples are a lighter weight alternative to objects when you want to group data…
As of v0.201.0, Flow can now lint against unused/floating Promises. Unused promises can be dangerous, because errors are potentially unhandled, and the code may not execute in the intended order. They are usually mistakes that Flow is perfectly positioned to warn you…
We announced 5 years ago a plan to eventually make exact object types the default. We are now proceeding with this plan. Starting with Flow 0.200, you must explicitly set either exact_by_default=true or exact_by_default=false in the [options] section of…
exact_by_default=true
exact_by_default=false
[options]
Over the course of 2021 and 2022, we have built LTI (Local Type Inference), a rewrite of Flow’s type inference algorithm. This change makes Flow’s inference behavior more reliable and predictable. It replaces a global inference scheme that Flow has relied on since its…
