cursorapi.js

var cursor = require('levelup-cursor')

/************************************** A *************************************/

db.readStream().pipe(cursor.each(function (data) {
  assert.equal(data,  {
    value: 'value',
    key: 'key'
  })
}, function (e) {
  assert.equal(e,  null)
}))

db.readStream().pipe(cursor.all(function (e, data) {
  assert.equal(e,  null)
  assert.equal(data, [{
    value: 'value',
    key: 'key'
  }, {
    value: 'value2',
    key: 'key2'
  }])
}))

/************************************** B *************************************/

db.readStream().pipe(cursor.each(function (data) {
  assert.equal(data,  {
    value: 'value',
    key: 'key'
  })
}, function (e) {
  assert.equal(e,  null)
}))

db.readStream().pipe(cursor.all(function (e, data) {
  assert.equal(e,  null)
  assert.equal(data, {
    'key': 'value',
    'key2': 'value2'
  })
}))

/************************************** C *************************************/

db.readStream().pipe(cursor.each(function (data) {
  assert.equal(data,  {
    'key': 'value'
  })
}, function (e) {
  assert.equal(e,  null)
}))

db.readStream().pipe(cursor.all(function (e, data) {
  assert.equal(e,  null)
  assert.equal(data, {
    'key': 'value',
    'key2': 'value2'
  })
}))

I personally prefer the explicitness of A but some of the feedback I've got from the batch() API is the it's too verbose for some people.

@rvagg thanks for the response.

While using the API I found the explicitness useful sometimes, and too verbose other times. It depends on what I need :/ Thats why I'm in doubt