A utility for upgrading your codebase to the latest version of Flow.
Install using yarn add flow-upgrade. We expect prettier to be installed as a peer dependency wherever you are running flow-upgrade.
You can then run:
yarn run flow-upgrade <current flow version> <target flow version>
You may also use npx:
npx flow-upgrade <current flow version> <target flow version>
We also supply the flow-codemod binary:
yarn run flow-codemod <codemod name>
If you just want to run a codemod without specifying Flow versions.
By default, Flow will only upgrade files that have an // @flow header comment.
If you want to upgrade all of your JavaScript files you may pass in the --all:
yarn create flow-upgrade --all
Path to a .prettierrc file to use.
Upgrade codemods rely upon prettier to print the resulting code after transformation.
If this is not provided, we will just use the defaults.
Converts static object assignments (e.g. const o = {}; o.a = 1;) to inline properties (e.g. const o = {a: 1};).
Run with yarn run flow-codemod collapseObjectInitialization.
Replaces T: {} with T: {...} in type parameter bounds. The former is almost always wrong.
Run with yarn run flow-codemod typeParameterBoundExactEmptyObjectToInexact.
Converts implicitly inexact object type syntax {} to explicitly inexact {...}.
Run with yarn run flow-codemod convertImplicitInexactObjectTypes.
Converts explicitly exact object type syntax {| |} to be just be { }. To be done after you turn on exact_by_default=true in your .flowconfig.
Run with yarn run flow-codemod removeExplicitlyExactObjectTypeSyntax.
Removes annotations nested inside of destructuring (e.g. const [o: number] = foo;). These are not valid Flow syntax.
Run with yarn run flow-codemod removeAnnotationsInDestructuring.
Part of the upgrade to 0.176
Removes useless duplicate class properties and fixes bad constructor binding in those classes.
Run with yarn run flow-codemod removeDuplicateClassProperties.
Part of the upgrade to 0.170
Renames usages of the $Partial utility type to its new name, Partial.
Run with yarn run flow-codemod renamePartial.
Part of the upgrade to 0.201
Converts usages of the deprecated and unsafe $Shape utility type to its replacement, Partial.
Run with yarn run flow-codemod convertShapeToPartial.