difference-accumulator
Accumulate differences in an object, get the total difference, reset the accumulator.
install
The normal way:
npm install difference-accumulator
use
Create a new accumulator with the original object:
const accumulator = require('difference-accumulator')
const originalData = {
firstName: 'Bilbo',
lastName: 'Baggins'
}
const acc = accumulator(originalData)
Apply a change:
acc.accumulate({ firstName: 'Frodo' })
Get out the sum of the changes:
const diff = acc.difference()
// diff = {
// firstName: 'Frodo'
// }
Undo the accumulated changes:
acc.clear()
const diff = acc.difference()
// diff = {}
api
acc = accumulator(originalData)
originalData
(object, optional)
Create a new accumulator by passing in an object property.
If originalData
is not specified, an object literal {}
will
be used.
acc.accumulate(delta)
delta
(object, optional)
The change to be applied to the original data.
If delta
is not specified, no difference will be accumulated.
For example:
acc.accumulate({
firstName: 'Frodo'
})
acc.accumulate({
relationships: {
uncle: 'Bilbo'
}
})
Will accumulate to the total delta:
const difference = {
firstName: 'Frodo',
relationships: {
uncle: 'Bilbo'
}
}
Accumulating falsey values (including undefined
) will
yield a difference which includes those properties:
const acc = accumulate({ firstName: 'Bilbo' })
acc.accumulate({ firstName: undefined })
// diff = {
// firstName: undefined
// }
Accumulating values identical to the original data will yield a difference which does not include that change:
const acc = accumulate({ firstName: 'Bilbo' })
acc.accumulate({ firstName: 'Bilbo' })
// diff = {}
Note that the comparison is done using ===
on each property, therefore:
const acc = accumulate({})
acc.accumulate({ firstName: undefined })
// diff = {}
acc.difference()
This will yield the current total accumulated difference.
acc.clear()
This will clear the total accumulated difference.
license
Published and released under the Very Open License.