72 lines
2.5 KiB
JavaScript

"use strict";
/* tslint:disable no-string-throw */
Object.defineProperty(exports, "__esModule", { value: true });
exports.isObjectReference = exports.isArrayEnd = exports.isArrayReference = exports.find = void 0;
const hasOwnProperty_1 = require("@jsonjoy.com/util/lib/hasOwnProperty");
const { isArray } = Array;
/**
* Finds a target in document specified by JSON Pointer. Also returns the
* object containing the target and key used to reference that object.
*
* Throws Error('NOT_FOUND') if pointer does not result into a value in the middle
* of the path. If the last element of the path does not result into a value, the
* lookup succeeds with `val` set to `undefined`. It can be used to discriminate
* missing values, because `undefined` is not a valid JSON value.
*
* If last element in array is targeted using "-", e.g. "/arr/-", use
* `isArrayEnd` to verify that:
*
* ```js
* const ref = find({arr: [1, 2, 3], ['arr', '-']});
* if (isArrayReference(ref)) {
* if (isArrayEnd(ref)) {
* // ...
* }
* }
* ```
*
* @param skipLast Number of steps to skip at the end. Useful to find reference of
* parent step, without constructing a new `Path` array.
*/
const find = (val, path) => {
const pathLength = path.length;
if (!pathLength)
return { val };
let obj;
let key;
for (let i = 0; i < pathLength; i++) {
obj = val;
key = path[i];
if (isArray(obj)) {
const length = obj.length;
if (key === '-')
key = length;
else {
if (typeof key === 'string') {
const key2 = ~~key;
if ('' + key2 !== key)
throw new Error('INVALID_INDEX');
key = key2;
if (key < 0)
throw new Error('INVALID_INDEX');
}
}
val = obj[key];
}
else if (typeof obj === 'object' && !!obj) {
val = (0, hasOwnProperty_1.hasOwnProperty)(obj, key) ? obj[key] : undefined;
}
else
throw new Error('NOT_FOUND');
}
const ref = { val, obj, key };
return ref;
};
exports.find = find;
const isArrayReference = (ref) => isArray(ref.obj) && typeof ref.key === 'number';
exports.isArrayReference = isArrayReference;
const isArrayEnd = (ref) => ref.obj.length === ref.key;
exports.isArrayEnd = isArrayEnd;
const isObjectReference = (ref) => typeof ref.obj === 'object' && typeof ref.key === 'string';
exports.isObjectReference = isObjectReference;