josdejong
immutable-json-patch
Immutable JSON patch with support for reverting operations.
Features:
- Apply JSON patch operations on a JSON document in an immutable way.
- Create inverse of the JSON patch operations to fully revert applied operations.
- Hook into the operations right before and after they are executed.
Try it out on a playground: https://josdejong.github.io/immutable-json-patch/
See http://jsonpatch.com/ for a clear description of the JSONPatch standard itself.
Install
$ npm install immutable-json-patchNote that in the lib folder, there are builds for ESM, UMD, and CommonJs.
Load
ESM:
import { immutableJSONPatch, revertJSONPatch } from 'immutable-json-patch'CommonJs:
const { immutableJSONPatch, revertJSONPatch } = require('immutable-json-patch')Use
Example from http://jsonpatch.com/#simple-example, using immutable-json-patch:
import { immutableJSONPatch, revertJSONPatch } from 'immutable-json-patch'
const document = {
baz: 'qux',
foo: 'bar'
}
console.log('document', document)
const operations = [
{ op: 'replace', path: '/baz', value: 'boo' },
{ op: 'add', path: '/hello', value: ['world'] },
{ op: 'remove', path: '/foo' }
]
console.log('operations', operations)
const updatedDocument = immutableJSONPatch(document, operations)
console.log('updatedDocument', updatedDocument)
// updatedDocument = {
// "baz": "boo",
// "hello": ["world"]
// }
const reverseOperations = revertJSONPatch(document, operations)
console.log('reverseOperations', reverseOperations)
// reverseOperations = [
// { op: 'add', path: '/foo', value: 'bar' },
// { op: 'remove', path: '/hello' },
// { op: 'replace', path: '/baz', value: 'qux' }
// ]
const revertedDocument = immutableJSONPatch(updatedJsonupdatedDocument, reverseOperations)
console.log('revertedDocument', revertedJsonrevertedDocument)
// revertedDocument = {
// "baz": "qux",
// "foo": "bar"
// }API
immutableJSONPatch(document, operations [, options]) => updatedDocument
Apply a list with JSON Patch operations to a JSON document.
declare function immutableJSONPatch<T, U = unknown> (document: T, operations: JSONPatchDocument, options?: JSONPatchOptions) : UWhere:
document: Tis a JSON documentoperations: JSONPatchDocumentis an array with JSONPatch operationsoptions: JSONPatchOptionsis an optional object allowing passing hooksbeforeandafter. With those hooks it is possible to alter the JSON document and/or applied operation before and after this is applied. This allows for example to instantiate classes or additional data structures when applying a JSON patch operation. Or you can keep certain data stats up to date. For example, it is possible to have an array withCustomerclass instances, and instantiate anew Customerwhen anaddoperation is performed. And in this library itself, thebeforecallback is used to create inverse operations whilst applying the actual operations on the document.The callbacks look like:
const options = { before: (document: unknown, operation: JSONPatchOperation) => { console.log('before operation', { document, operation }) // return { document?: unknown, operation?: JSONPatchOperation } | undefined }, after: (document: unknown, operation: JSONPatchOperation, previousDocument: unknown) => { console.log('after operation', { document, operation, previousDocument }) // return document | undefined } }When the
beforeoraftercallback returns an object with altereddocument, this will be used to apply the operation. When and alteredoperationis returned frombeforein an object, this operation will be applied instead of the original operation.
The function returns an updated JSON document where the JSON patch operations are applied. The original JSON document is not changed.
revertJSONPatch(document, operations, options) => reverseOperations
Generate the JSON patch operations that will revert the provided list with JSON Patch operations when applied to the provided JSON document.
declare function revertJSONPatch<T, U> (document: T, operations: JSONPatchDocument, options?: RevertJSONPatchOptions) : JSONPatchDocumentWhere:
document: Tis a JSON documentoperations: JSONPatchDocumentis an array with JSONPatch operationsoptions: JSONPatchOptionsis an optional object allowing passing a hookbefore. With this hook it is possible to alter the JSON document and/or generatedreverseOperationsbefore this is applied.
The function returns a list with the reverse JSON Patch operations. These operations can be applied to the updated JSON document (the output of immutableJSONPatch) to restore the original JSON document.
util functions
The library exposes a set of utility functions and typeguards to work with JSON pointers and to do immutable operations on JSON data:
declare function parsePath<T>(document: T, path: JSONPointer): JSONPath
declare function parseFrom(path: JSONPointer): JSONPath
declare function parseJSONPointer (pointer: JSONPointer) : JSONPath
declare function compileJSONPointer (path: JSONPath) : JSONPointer
declare function compileJSONPointerProp (pathProp: string | number) : JSONPointer
declare function appendToJSONPointer (pointer: JSONPointer, pathProp: string | number) : JSONPointer
declare function startsWithJSONPointer (pointer: JSONPointer, searchPointer: JSONPointer) : boolean
declare function isJSONPatchOperation(operation: unknown): operation is JSONPatchOperation
declare function isJSONPatchAdd(operation: unknown): operation is JSONPatchAdd
declare function isJSONPatchRemove(operation: unknown): operation is JSONPatchRemove
declare function isJSONPatchReplace(operation: unknown): operation is JSONPatchReplace
declare function isJSONPatchCopy(operation: unknown): operation is JSONPatchCopy
declare function isJSONPatchMove(operation: unknown): operation is JSONPatchMove
declare function isJSONPatchTest(operation: unknown): operation is JSONPatchTest
declare function getIn<T, U = unknown>(object: U, path: JSONPath) : T | undefined
declare function setIn<T, U = unknown, V = unknown> (object: U, path: JSONPath, value: V, createPath = false) : T
declare function updateIn<T, U = unknown, V = unknown> (object: T, path: JSONPath, transform: (value: U) => V) : T
declare function deleteIn<T, U = unknown> (object: U, path: JSONPath) : T
declare function existsIn<T> (document: T, path: JSONPath) : boolean
declare function insertAt<T, U = unknown> (document: T, path: JSONPath, value: U) : T
declare function transform <T, U = unknown, V = unknown, W = unknown> (
document: U,
callback: (document: V, path: JSONPath) => W, path: JSONPath = []
) : T Develop
To build the library (ESM, CommonJs, and UMD output in the folder lib):
$ npm install
$ npm run buildTo run the unit tests:
$ npm testTo run the linter (eslint):
$ npm run lintTo run the linter, build all, and run unit tests and integration tests:
$ npm run build-and-testLicense
Released under the ISC license.