diff-mapper v1.1.4

diff-mapper

diff-mapper is a JavaScript vanilla module for mapping differences between objects.

Installation

Use the package manager npm to install diff-mapper.

npm i diff-mapper

Usage

import diffMapper, { DiffMapResult, ValueDiffType } from 'diff-mapper';

const object1 = { a: 1 };
const object2 = { a: 1 };
const diff = diffMapper.map(object1, object2);
console.info(diff);
{ a: { type: 'UNCHANGED', currentValue: 1, newValue: 1 } }

Examples

1 - Simple object diff, unchanged property

const object1 = { a: 1 };
const object2 = { a: 1 };
const diff = diffMapper.map(object1, object2);
console.info(diff);
{ a: { type: 'UNCHANGED', currentValue: 1, newValue: 1 } }

2 - Simple object diff, added property and removed other

const object1 = { a: 1 };
const object2 = { b: 1 };
const diff = diffMapper.map(object1, object2);
console.info(diff);
{
  a: { type: 'DELETED', currentValue: 1, newValue: undefined },
  b: { type: 'CREATED', currentValue: undefined, newValue: 1 }
}

3 - Nested objects, supporting changing types

import diffMapper, { DiffMapResult, ValueDiffType } from 'diff-mapper';

const object1 = {
  a: 'i am unchanged',
  b: 'i am deleted',
  e: {
    a: 1,
    b: false,
    c: null,
  },
  f: [1, {
    a: 'same',
    b: [{
      a: 'same',
    }, {
      d: 'delete',
    }],
  }],
  g: new Date('2020.05.04'),
};

const object2 = {
  a: 'i am unchanged',
  c: 'i am created',
  e: { a: '1', b: '', d: 'created' },
  f: [{
    a: 'same',
    b: [{ a: 'same' }, { c: 'create' }],
  }, 1],
  g: new Date('2020.05.04'),
};

const diff = diffMapper.map(object1, object2);
console.info(diff);
{
      a: {
        type: 'UNCHANGED',
        currentValue: 'i am unchanged',
        newValue: 'i am unchanged',
      },
      b: {
        type: 'DELETED',
        currentValue: 'i am deleted',
        newValue: undefined,
      },
      c: {
        type: 'CREATED',
        currentValue: undefined,
        newValue: 'i am created',
      },
      e: {
        a: {
          type: 'UPDATED',
          currentValue: 1,
          newValue: '1',
        },
        b: {
          type: 'UPDATED',
          currentValue: false,
          newValue: '',
        },
        c: {
          type: 'DELETED',
          currentValue: null,
          newValue: undefined,
        },
        d: {
          type: 'CREATED',
          currentValue: undefined,
          newValue: 'created',
        },
      },
      f: {
        0: {
          type: 'UPDATED',
          currentValue: 1,
          newValue: {
            a: 'same',
            b: [{ a: 'same' }, { c: 'create' }],
          },
        },
        1: {
          type: 'UPDATED',
          currentValue: {
            a: 'same',
            b: [{ a: 'same' }, { d: 'delete' }],
          },
          newValue: 1,
        },
      },
      g: {
        type: 'UNCHANGED',
        currentValue: new Date('2020.05.04'),
        newValue: new Date('2020.05.04'),
      },
    }
}

4 - Arrays

import diffMapper, { DiffMapResult } from 'diff-mapper';

const diff = diffMapper.map([1, 2, 3], [1, 2, 3, 4, 5, 6]);
console.info(diff);
{
  0: { type: 'UNCHANGED', currentValue: 1, newValue: 1 },
  1: { type: 'UNCHANGED', currentValue: 2, newValue: 2 },
  2: { type: 'UNCHANGED', currentValue: 3, newValue: 3 },
  3: { type: 'CREATED', currentValue: undefined, newValue: 4 },
  4: { type: 'CREATED', currentValue: undefined, newValue: 5 },
  5: { type: 'CREATED', currentValue: undefined, newValue: 6 },
}

Utils

diffMapper.toArray - returns DiffMapResult represented as an array
diffMapper.toString - returns DiffMapResult stringified

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

Apache 2.0