react/packages/shared/ReactErrorProd.js
Andrew Clark 42c3c967d1
Compile invariant directly to throw expressions (#15071)
* Transform invariant to custom error type

This transforms calls to the invariant module:

```js
invariant(condition, 'A %s message that contains %s', adj, noun);
```

Into throw statements:

```js
if (!condition) {
  if (__DEV__) {
    throw ReactError(`A ${adj} message that contains ${noun}`);
  } else {
    throw ReactErrorProd(ERR_CODE, adj, noun);
  }
}
```

The only thing ReactError does is return an error whose name is set
to "Invariant Violation" to match the existing behavior.

ReactErrorProd is a special version used in production that throws
a minified error code, with a link to see to expanded form. This
replaces the reactProdInvariant module.

As a next step, I would like to replace our use of the invariant module
for user facing errors by transforming normal Error constructors to
ReactError and ReactErrorProd. (We can continue using invariant for
internal React errors that are meant to be unreachable, which was the
original purpose of invariant.)

* Use numbers instead of strings for error codes

* Use arguments instead of an array

I wasn't sure about this part so I asked Sebastian, and his rationale
was that using arguments will make ReactErrorProd slightly slower, but
using an array will likely make all the functions that throw slightly
slower to compile, so it's hard to say which way is better. But since
ReactErrorProd is in an error path, and fewer bytes is generally better,
no array is good.

* Casing nit
2019-03-18 13:58:03 -07:00

26 lines
863 B
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
*/
// Do not require this module directly! Use a normal error constructor with
// template literal strings. The messages will be converted to ReactError during
// build, and in production they will be minified.
function ReactErrorProd(code) {
let url = 'https://reactjs.org/docs/error-decoder.html?invariant=' + code;
for (let i = 1; i < arguments.length; i++) {
url += '&args[]=' + encodeURIComponent(arguments[i]);
}
return new Error(
`Minified React error #${code}; visit ${url} for the full message or ` +
'use the non-minified dev environment for full errors and additional ' +
'helpful warnings. ',
);
}
export default ReactErrorProd;