react/eslint-rules/no-primitive-constructors.js
Sophie Alpert d63249d034 Update license headers BSD+Patents -> MIT
Did find and replace in TextMate.

```
find: (?:( \*)( ))?Copyright (?:\(c\) )?(\d{4})\b.+Facebook[\s\S]+(?:this source tree|the same directory)\.$
replace: $1$2Copyright (c) $3-present, Facebook, Inc.\n$1\n$1$2This source code is licensed under the MIT license found in the\n$1$2LICENSE file in the root directory of this source tree.
```
2017-09-25 18:17:44 -07:00

51 lines
1.1 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @emails react-core
*/
'use strict';
module.exports = function(context) {
function report(node, name, msg) {
context.report(node, `Do not use the ${name} constructor. ${msg}`);
}
function check(node) {
const name = node.callee.name;
switch (name) {
case 'Boolean':
report(
node,
name,
'To cast a value to a boolean, use double negation: !!value'
);
break;
case 'String':
report(
node,
name,
'To cast a value to a string, concat it with the empty string ' +
'(unless it\'s a symbol, which has different semantics): ' +
'\'\' + value'
);
break;
case 'Number':
report(
node,
name,
'To cast a value to a number, use the plus operator: +value'
);
break;
}
}
return {
CallExpression: check,
NewExpression: check,
};
};