I have react@15 and chrome 59.0.3071.115.
With a little tweak in code, I was able to find out the possible cause.

Firstly I made specialProperty any string, including zeroWidthSpace, works fine.
Then I changed it back to Symbol, the function was not called.

then I attached a debugger to validator..

  propertyOne: PropTypes.string,
  propertyTwo: () => {
    debugger
    return null
  },

I was able to reach this frame

and the checkType function

It turns out that when doing the for... in, the symbol would not be found as a key.

I have immutable.js in several of my projects. Can I use prop-types-exact in my case?

Some HOC does provide multiple props, when sometimes you do not want all of them.

Example: withRouter from react-router adds match, location and history.

A simple approach might to add them in the prop-types, but no-unused-prop-types will throw in this case.

Imagine the following component:

function SomeComponent({ history }) {
  return <button onClick={() => history.push('/')}>go somewhere</button>;
}
SomeComponent.propTypes = exact({
  history: PropTypes.object.isRequired,
});

export default withRouter(SomeComponent);

Actually I would have to do this:

function SomeComponent({ history }) {
  return <button onClick={() => history.push('/')}>go somewhere</button>;
}
SomeComponent.propTypes = exact({
  history: PropTypes.object.isRequired,
  match: PropTypes.any, // eslint-disable-line
  location: PropTypes.any, // eslint-disable-line
});

export default withRouter(SomeComponent);

Should the exact() function takes a ignore list parameter like this ?

function SomeComponent({ history }) {
  return <button onClick={() => history.push('/')}>go somewhere</button>;
}
SomeComponent.propTypes = exact({
  history: PropTypes.object.isRequired,
}, ['match', 'location']);

export default withRouter(SomeComponent);

If React supports it, then in Symbol-supporting environments (use has-symbols to check), use a Symbol instead of a zero-width space.

There's no effect (no error) when adding extra props to a component that has exact wrapping its propTypes.

We're using [email protected] with [email protected].

See airbnb/prop-types#75

Just like in airbnb-prop-types, this package should noop in production, but should provide the functionality unconditionally via a separate entry point.

I was trying to use the library in a Typescript project but when doing the import it throws the following error:

Could not find a declaration file for module 'prop-types-exact'. '/Users/victorcasas/Documents/projects/mkt/node_modules/prop-types-exact/build/index.js' implicitly has an 'any' type.
Try npm i --save-dev @types/prop-types-exact if it exists or add a new declaration (.d.ts) file containing declare module 'prop-types-exact';ts(7016)

I tried to install @types/ following the instructions in the error, but I realized that the library does not exist.

As this package is intended to be paired with React it makes sense to use here the same Object.assign implementation (object-assign) they use to reduce duplication in bundles.

Doing this will reduce the page load of a Next.js hello world app by 661 B (min gzip):

I'm seeing these now that I use exact:

The description says that the library will throw an error on non explicitly set props, but in the example, it says it will throw a "warning".

Ambiguity should be removed by using only "error".

Hi there, it seems this package and forbidExtraProps from airbnb/prop-types are similar. Can you explain the differences and when should we use this or forbidExtraProps?

Thanks!

Is there any way to make it work together with the ESLint plugin eslint-plugin-react or is there any ESLint plugin which I'm missing?

The rules which I'm currently using and aren't compatible with the usage of prop-types-exact are no-unused-prop-types and prop-types