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@babel/plugin-transform-flow-strip-types

info

This plugin is included in @babel/preset-flow

Example​

In

JavaScript
function foo(one: any, two: number, three?): string {}

Out

JavaScript
function foo(one, two, three) {}

Installation​

npm install --save-dev @babel/plugin-transform-flow-strip-types

Usage​

babel.config.json
{
  "plugins": ["@babel/plugin-transform-flow-strip-types"]
}

Via CLI​

Shell
babel --plugins @babel/plugin-transform-flow-strip-types script.js

Via Node API​

JavaScript
require("@babel/core").transformSync("code", {
  plugins: ["@babel/plugin-transform-flow-strip-types"],
});

Options​

all​

boolean, defaults to false.

Flow will only parse Flow-specific features if a @flow pragma is present atop the file, or the all option is set inside the .flowconfig.

If you are using the all option in your Flow config, be sure to set this option to true to get matching behavior.

For example, without either of the above, the following call expression with a type argument:

f<T>(e)

Would get parsed as a nested binary expression:

JavaScript
f < T > e;

requireDirective​

boolean, defaults to false.

Setting this to true will only strip annotations and declarations from files that contain the // @flow directive. It will also throw errors for any Flow annotations found in files without the directive.

allowDeclareFields​

boolean, defaults to false

Added in: v7.9.0

note

This will be enabled by default in Babel 8

When enabled, type-only class fields are only removed if they are prefixed with the declare modifier:

JavaScript
class A {
  declare foo: string; // Removed
  bar: string; // Initialized to undefined
}
tip

You can read more about configuring plugin options here