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https://github.com/marcolink/generate-json-patch
A simple function to diff any object and generate a JSON Patch
https://github.com/marcolink/generate-json-patch
generator javascript json jsonpatch typescript
Last synced: about 2 months ago
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A simple function to diff any object and generate a JSON Patch
- Host: GitHub
- URL: https://github.com/marcolink/generate-json-patch
- Owner: marcolink
- License: mit
- Created: 2023-07-14T07:25:29.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-09-04T22:33:13.000Z (4 months ago)
- Last Synced: 2024-11-01T09:57:51.268Z (2 months ago)
- Topics: generator, javascript, json, jsonpatch, typescript
- Language: TypeScript
- Homepage:
- Size: 178 KB
- Stars: 6
- Watchers: 1
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# generate-json-patch
Create [RFC 6902](https://datatracker.ietf.org/doc/html/rfc6902/) compliant JSON Patch objects based on two given [JSON](https://www.ecma-international.org/publications-and-standards/standards/ecma-404/) objects with a configurable interface.
[](https://npmjs.org/package/generate-json-patch)
[](https://npmjs.org/package/generate-json-patch)
[](https://npmjs.org/package/generate-json-patch)
[](https://github.com/marcolink/generate-json-patch/actions/workflows/test.yml)
[](https://github.com/marcoxlink/generate-json-patch/blob/main/package.json)
[](http://www.typescriptlang.org/)
# TL;DR
- Can diff any two [JSON](https://www.ecma-international.org/publications-and-standards/standards/ecma-404/) compliant objects - returns differences as [JSON Patch](http://jsonpatch.com/).
- Elegant array diffing by providing an `objectHash` to match array elements
- Ignore specific keys by providing a `propertyFilter`
- :paw_prints: ***Is it small?*** Zero dependencies - it's ~**3 KB** (minified).
- :crystal_ball: ***Is it fast?*** I haven't done any performance comparison yet.
- :hatched_chick: ***Is it stable?*** Test coverage is high, but it's still in its early days - bugs are expected.
- The interface is inspired by [jsondiffpatch](https://github.com/benjamine/jsondiffpatch)
- **100%** Typescript
# Installation
Works on node and browser environments.
```bash
npm install generate-json-patch
```
# Usage
```typescript
import { generateJSONPatch } from 'generate-json-patch';
const before = { manufacturer: "Ford", type: "Granada", year: 1972 };
const after = { manufacturer: "Ford", type: "Granada", year: 1974 };
const patch = generateJSONPatch(before, after);
console.log(patch) // => [{op: 'replace', path: '/year', value: 1974}]
```
## Configuration
```typescript
import { generateJSONPatch, JsonPatchConfig, JsonValue, ObjectHashContext } from 'generate-json-patch';
generateJSONPatch({/*...*/}, {/*...*/}, {
// called when comparing array elements
objectHash: function(value: JsonValue, context: GeneratePatchContext) {
// for arrays of primitive values like string and numbers, a stringification is sufficent:
// return JSON.stringify(value)
// If we know the shape of the value, we can match be specific properties
return value.name
},
// called for every property on objects. Can be used to ignore sensitive or irrelevant
// properties when comparing data.
propertyFilter: function (propertyName: string, context: ObjectHashContext) {
return !['sensitiveProperty'].includes(propertyName);
},
array: {
// When true, no move operations will be created.
// The rersulting patch will not lead to identical objects,
// as postions of array elements can be different!
ignoreMove: true
}
});
```
### Patch Context
Both config function (`objectHash`, `propertyFilter`), receive a context as second parameter.
This allows for granular decision-making on the provided data.
#### Example
```typescript
import {generateJSONPatch, JsonPatchConfig, JsonValue, ObjectHashContext, pathInfo} from 'generate-json-patch';
const before = {
manufacturer: "Ford",
type: "Granada",
colors: ['red', 'silver', 'yellow'],
engine: [
{ name: 'Cologne V6 2.6', hp: 125 },
{ name: 'Cologne V6 2.0', hp: 90 },
{ name: 'Cologne V6 2.3', hp: 108 },
{ name: 'Essex V6 3.0', hp: 138 },
]
}
const after = {
manufacturer: "Ford",
type: "Granada",
colors: ['red', 'silver', 'yellow'],
engine: [
{name: 'Essex V6 3.0', hp: 138},
{name: 'Cologne V6 2.6', hp: 125},
{name: 'Cologne V6 2.0', hp: 90},
{name: 'Cologne V6 2.3', hp: 108},
]
}
const patch = generateJSONPatch(before, after, {
objectHash: function (value: JsonValue, context: ObjectHashContext) {
const {length, last} = pathInfo(context.path)
if (length === 2 && last === 'engine') {
return value.name
}
return JSON.stringify(value)
}
});
console.log(patch) // => [
// { op: 'replace', path: '/engine/3/hp', value: 138 },
// { op: 'move', from: '/engine/3', path: '/engine/0' }
// ]
```
> For more examples, check out the [tests](./src/index.spec.ts)