signal-desktop/ts/util/reallyJsonStringify.ts
2021-01-27 13:13:33 -08:00

43 lines
1.1 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
/**
* Returns `JSON.stringify(value)` if that returns a string, otherwise returns a value
* like `[object Object]` or `[object Undefined]`.
*
* `JSON.stringify` doesn't always return a string. Some examples:
*
* JSON.stringify(undefined) === undefined
*
* JSON.stringify(Symbol()) === undefined
*
* JSON.stringify({ toJSON() {} }) === undefined
*
* const a = {};
* const b = { a };
* a.b = a;
* JSON.stringify(a); // => Throws a TypeError
*
* JSON.stringify(123n); // => Throws a TypeError
*
* const scary = {
* toJSON() {
* throw new Error('uh oh');
* }
* };
* JSON.stringify(scary); // => Throws "uh oh"
*
* This makes sure we return a string and don't throw.
*/
export function reallyJsonStringify(value: unknown): string {
let result: unknown;
try {
result = JSON.stringify(value);
} catch (_err) {
result = undefined;
}
return typeof result === 'string'
? result
: Object.prototype.toString.call(value);
}