json-compare-engine

Compare Engine

Installation

• From npm: npm install compare-engine
• From yarn: yarn add compare-engine

Test

• From npm: npm test
• From yarn: yarn test

About

Compares 2 json, considering array object movement :

• Either with a signature (identical object)
• Or with a key defined by the method passed to the constructor
• The search is recursive: if an object has been moved within a moved object, it will be detected as moved

Examples

import {CompareEngine} from 'compare-engine';

const jsonLeft = {
    objectArray: [
        {
            id: "movedIndex",
            property: "old property",
            otherObjectArray: [
                {id: "1"},
                {id: "2"},
            ],
            otherArray: [
                0, 1, 2
            ]
        },
        {
            id: "removedObject",
        },
        {
            id: "equal"
        }
    ]
};
const jsonright = {
    objectArray: [
        {
            id: "newObject",
        },
        {
            id: "movedIndex",
            property: "updated property",
            otherObjectArray: [
                {id: "2"},
                {id: "1"},
            ],
            otherArray: [
                2, 1, 3
            ]
        },
        {
            id: "equal"
        }
    ]
};

const compareEngine = new CompareEngine((paths: string[]) => {
  return "id";
});

compareEngine.updateLeft(jsonLeft);
compareEngine.updateRight(jsonRight);

compareEngine.updateCompareIndex();

compareEngine.getLeftState("") // return UPDATED CompareState
compareEngine.getLeftState("objectArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/0/property") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/otherObjectArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/otherObjectArray/0") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/otherObjectArray/0/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/0/otherObjectArray/1") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/otherObjectArray/1/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/0/otherArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0/otherArray/0") // return REMOVED CompareState
compareEngine.getLeftState("objectArray/0/otherArray/1") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/0/otherArray/2") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1") // return REMOVED CompareState
compareEngine.getLeftState("objectArray/1/id") // return NONE CompareState
compareEngine.getLeftState("objectArray/2") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/2/id") // return NONE CompareState

compareEngine.getLeftState("") // return UPDATED CompareState
compareEngine.getLeftState("objectArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/0") // return ADDED CompareState
compareEngine.getLeftState("objectArray/0/id") // return NONE CompareState
compareEngine.getLeftState("objectArray/1") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/1/property") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherObjectArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherObjectArray/0") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherObjectArray/0/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/1/otherObjectArray/1") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherObjectArray/1/id") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/1/otherArray") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherArray/0") // return UPDATED CompareState
compareEngine.getLeftState("objectArray/1/otherArray/1") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/1/otherArray/2") // return ADDED CompareState
compareEngine.getLeftState("objectArray/2") // return EQUAL CompareState
compareEngine.getLeftState("objectArray/2/id") // return NONE CompareState

Exposed models, enums and utils

class CompareEngine {
    constructor(protected determineArrayIndexFn?: (paths: string[]) => string)

    updateLeft(json: any): void
    updateRight(json: any): void

    updateCompareIndex(): void

    hasChange(): boolean

    getLeftState(paths: string[] | string): CompareState
    getRightState(paths: string[] | string): CompareState
}

class CompareState {
    value: CompareStateEnum

    isNone(): boolean
    isAdded(): boolean
    isUpdated(): boolean
    isRemoved(): boolean
    isEqual(): boolean
    isChanged(): boolean

    toString(): string
}

enum CompareStateEnum {
    NONE = "",
    ADDED = "added",
    UPDATED = "updated",
    REMOVED = "removed",
    EQUAL = "equal",
}

abstract class CompareUtils {
    static isNumber(num: JsonPrimitive): num is number
    static isArray<T>(arr: unknown): arr is T[]
    static isString(str: unknown): obj is string
    static isObject(obj: unknown): obj is JsonObject

    static isEqual(sideValue: unknown, otherSideValue: unknown): boolean

    static deepClone<T, I>(source: T): T
}

License

Apache License, Version 2.0