react-native/Libraries/Utilities/stringifySafe.js

49 lines
1.2 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.
*
* @format
* @flow
*/
'use strict';
/**
* Tries to stringify with JSON.stringify and toString, but catches exceptions
* (e.g. from circular objects) and always returns a string and never throws.
*/
function stringifySafe(arg: any): string {
let ret;
const type = typeof arg;
if (arg === undefined) {
ret = 'undefined';
} else if (arg === null) {
ret = 'null';
} else if (type === 'string') {
ret = '"' + arg + '"';
} else if (type === 'function') {
try {
ret = arg.toString();
} catch (e) {
ret = '[function unknown]';
}
} else {
// Perform a try catch, just in case the object has a circular
// reference or stringify throws for some other reason.
try {
ret = JSON.stringify(arg);
} catch (e) {
if (typeof arg.toString === 'function') {
try {
ret = arg.toString();
} catch (E) {}
}
}
}
return ret || '["' + type + '" failed to stringify]';
}
module.exports = stringifySafe;