Compare Engine

Installation

* From npm: npm install @alkemist/compare-engine
* From yarn: yarn add @alkemist/compare-engine

Test

* From npm: npm test
* From yarn: yarn test

About

Compares 2 value, 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
- Takes into consideration : value type/class, function name and signature (without parameter type)

Examples

$3

import {CompareEngine} from '@alkemist/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 MOVED CompareState
compareEngine.getLeftState("objectArray[0].otherObjectArray[0].id") // return NONE CompareState
compareEngine.getLeftState("objectArray[0].otherObjectArray[1]") // return MOVED CompareState
compareEngine.getLeftState("objectArray[0].otherObjectArray[1].id") // return NONE 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 MOVED 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.getRightState("") // return UPDATED CompareState
compareEngine.getRightState("objectArray") // return UPDATED CompareState
compareEngine.getRightState("objectArray[0]") // return ADDED CompareState
compareEngine.getRightState("objectArray[0].id") // return NONE CompareState
compareEngine.getRightState("objectArray[1]") // return UPDATED CompareState
compareEngine.getRightState("objectArray[1].id") // return EQUAL CompareState
compareEngine.getRightState("objectArray[1].property") // return UPDATED CompareState
compareEngine.getRightState("objectArray[1].otherObjectArray") // return UPDATED CompareState
compareEngine.getRightState("objectArray[1].otherObjectArray[0]") // return MOVED CompareState
compareEngine.getRightState("objectArray[1].otherObjectArray[0].id") // return NONE CompareState
compareEngine.getRightState("objectArray[1].otherObjectArray[1]") // return MOVED CompareState
compareEngine.getRightState("objectArray[1].otherObjectArray[1].id") // return NONE CompareState
compareEngine.getRightState("objectArray[1].otherArray") // return UPDATED CompareState
compareEngine.getRightState("objectArray[1].otherArray[0]") // return MOVED CompareState
compareEngine.getRightState("objectArray[1].otherArray[1]") // return EQUAL CompareState
compareEngine.getRightState("objectArray[1].otherArray[2]") // return ADDED CompareState
compareEngine.getRightState("objectArray[2]") // return EQUAL CompareState
compareEngine.getRightState("objectArray[2].id") // return NONE CompareState

$3

class Parent {
constructor(protected property = "value") {
}
}

class Child extends Parent {
constructor(protected override property = "value") {
super();
}
}

const compareEngine = new CompareEngine((paths: string[]) => {
return "id";
}, new Parent(), new Parent());
compareEngine.updateCompareIndex();
compareEngine.getLeftState("") // return EQUAL CompareState

const compareEngine = new CompareEngine((paths: string[]) => {
return "id";
}, new Parent(), new Child());
compareEngine.updateCompareIndex();
compareEngine.getLeftState("") // return UPDATED CompareState

const compareEngine = new CompareEngine((paths: string[]) => {
return "id";
}, new Child(), new Child("otherValue"));
compareEngine.updateCompareIndex();
compareEngine.getLeftState("") // return UPDATED CompareState

Exposed models, enums and utils

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

class CompareEngine {
constructor(
protected determineArrayIndexFn?: (paths: ValueKey[]) => ValueKey
leftValue?: DATA_TYPE = null,
rightValue?: DATA_TYPE = null
)

get leftValue(): DATA_TYPE | undefined
get rightValue(): DATA_TYPE | undefined

getInLeft(paths: ValueKey[] | ValueKey): unknown
getInRight(paths: ValueKey[] | ValueKey): unknown

updateLeft(value: DATA_TYPE | undefined): void
updateRight(value: DATA_TYPE | undefined): void

updateInLeft(value: DATA_TYPE | undefined, paths: ValueKey[] | ValueKey): void
updateInRight(value: DATA_TYPE | undefined, paths: ValueKey[] | ValueKey): void

leftToRight(): void
rightToLeft(): void

updateCompareIndex(): void

hasChange(): boolean

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

class CompareState {
value: CompareStateEnum

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

toString(): string
}

License

Apache License, Version 2.0