@crikey/json

JSON types and utility functions

See @crikey/json for full documentation.

API

Types

Contains types used to represent JSON and JSON equivalents.

Primary types:

• Json - A pure JSON type. Contained values may not be undefined.
• Jsonish - A JSON type which allows for contained values to be undefined.

Guards

Contains typescript guards for identifying type information.

• is_undefined returns true if value is undefined
• is_null returns true if value is null
• is_boolean returns true if value is a boolean
• is_integer returns true if value is an integer
• is_safe_integer returns true if value is a safe integer
• is_index_number returns true if value is a positive integer
• is_index_string returns true if value is the string equivalent of a positive integer
• is_index_number_or_string returns true if either is_index_number or is_index_string is true
• is_number returns true if value is a number
• is_finite_number returns true if value is a finite number
• is_string returns true if value is a string
• is_primitive returns true if value is a json primitive
• is_encodable_primitive returns true if value is an encodable primitive
• is_object returns true if value is an object (but not an array)
• is_array returns true if value is an array
• is_container returns true if either is_object or is_array is true
• is_json returns true if a shallow check of value confirms a json type
• is_json_deep returns true if a deep check of value confirms every contained value is a json type
• is_encodable_json returns true if a shallow check of value confirms it is an encodable json type
• is_encodable_json_deep returns true if a deep check of value confirms every contained value is an encodable json type
• is_equal_deep returns true if a deep comparison of values proves equality

Access

• object_has_key returns true if object has an ownProperty with the given name

• object_has_defined_key returns true if object has an ownProperty with the given name whose value is not undefined

• object_member returns the value of the given ownProperty

• object_entries returns all ownProperty entries of value

• object_defined_entries returns all ownProperty entries of value whose values are not undefined

• object_keys returns all ownProperty keys of value

• object_defined_keys returns all ownProperty keys of value whose values are not undefined

• array_has_index returns true if array has the given index

• array_element returns the value of the given index

• container_has_key_or_index returns true if value has the given index/key

• container_has_defined_key_or_index returns true if value has the given index/key, and it's value is not undefined

• container_item return the value of the given key/index

Traversal

Provides methods for the following activities:

• traverse_has | traverse_json.has, traverse_has | traverse_jsonish.has returns true if the given path exists
• traverse_get | traverse_json.get, traverse_get | traverse_jsonish.get returns the value resulting from traversing the given path
• traverse_json_set | traverse_json.set, traverse_jsonish_set | traverse_jsonish.set traverses the given path, creating objects and arrays as necessary, and sets the leaf node value
• traverse_json_update | traverse_json.update, traverse_jsonish_update | traverse_jsonish.update traverses the given path, creating objects and arrays as necessary, and updates the leaf node value
• traverse_delete | traverse_json.delete, traverse_delete | traverse_jsonish.delete traverses the given path, deleting the leaf node if it exists

Utilities

• clone Returns a deep clone of the given value Json or Jsonish value

• parse_index Parses the given encoded_index into an index, or undefined if it is invalid

• parse_index_string Returns the given encoded_index parsed into a numerical index, or undefined if the string does not represent a valid index

• object_assign Safe version of Object.assign which doesn't risk polluting the result object via __proto__

Installation

# pnpm
$ pnpm add @crikey/json

# npm
$ npm add @crikey/json

# yarn
$ yarn add @crikey/json

Example Usage

Example Guards

const value: any = {a: NaN};

console.log(is_json(value)); // true
console.log(is_json_deep(value)); // true
console.log(is_encodable_json_deep(value)); // false - NaN is not a valid JSON value and will be cooerced into a null

const value: any = {a: undefined};

console.log(is_json(value)); // true
console.log(is_json_deep(value)); // false - json does not support undefined values
console.log(is_jsonish_deep(value)); // true - jsonish does support undefined values

Example Access

const parent = {x: 1};
const child = {y: 1};
child.__proto__ = parent;

console.log('x' in child); // true
console.log(object_has_key(child, 'x')); // false
console.log(object_has_key(child, 'y')); // true
console.log(object_keys(child)); // ['y']
console.log(object_entries(child)); // [['y', 2]]

import {array_has_index} from "./array_has_index";

const value = ['a', 'b', 'c'];

console.log(array_has_index(value, 0)); // true
console.log(array_has_index(value, 3)); // false
console.log(array_element(value, 1)); // 'b'

Example Traverse

import {traverse_get} from "./traverse_get";
import {traverse_json} from "./traverse_json";

const value = {foo: ['bar', 'baz']};

console.log(traverse_json.get(value, ['foo', 0])); // 'bar'
console.log(traverse_json.get(value, ['foo', 1])); // 'baz'
console.log(traverse_json.get(value, ['fah'])); // undefined
console.log(traverse_json.set(value, ['fah'], 1)); // {foo: ['bar', 'baz'], fah: 1}

Example Util

const value = 'my value';
const type: JsonTypeEnum = get_type(value); 
console.log(type); // 'string'

const value = {a: 1, b: undefined, c:[]};
const cloned = clone(value);

console.log(cloned); // {a: 1, b: undefined, c:[]}

import {parse_index} from "./parse_index";

console.log(parse_index(1)); // 1
console.log(parse_index(1.1)); // undefined
console.log(parse_index('1')); // 1
console.log(parse_index('1.1')); // undefined

console.log(parse_index_string('1')); // 1
console.log(parse_index_string('1.1')); // undefined

const unsafe = Object.assign({}, { ['__proto__']: { x: 1 }});
const safe = object_assign({}, { ['__proto__']: { x: 1 }});

console.log(unsafe); // {}
console.log(safe); // { ['__proto__']: { x: 1 }}