Formatter

Given a saved item, validates that it respects the schema and formats it:

import { Formatter } from 'dynamodb-toolbox/schema/actions/format'

const formattedPikachu = pokemonSchema
  .build(Formatter)
  .format(savedPikachu)

Note that:

• Additional and hidden fields are omitted, but inputs are not mutated
• The formatting throw an error if the saved item is invalid
• Transformations (i.e. savedAs and transforms) are applied in reverse

Methods

format(...)

(savedValue: unknown, options?: FormatValueOptions) => FormattedValue<SCHEMA>

Formats a saved item:

const formattedValue = pokemonSchema.build(Formatter).format(savedValue)

You can provide formatting options as a second argument. Available options:

Option	Type	Default	Description
partial	boolean	false	Allow every attribute (flat or deep) to be optional while formatting.
attributes	Path<Schema>[]	-	To specify a list of attributes to format (other attributes are omitted). See the PathParser action for more details on how to write attribute paths.

Examples

Partial

const saved = {
  pokemonId: 'pikachu1',
  name: 'Pikachu'
}

// 🙌 Typed as `DeepPartial<Pokemon>`
const formatted = pokemonSchema
  .build(Formatter)
  .format(saved, { partial: true })

Attributes

const saved = {
  pokemonId: 'pikachu1',
  name: 'Pikachu',
  level: 42,
  ...
}

// 🙌 Typed as `Pick<Pokemon, 'name' | 'level'>`
const formatted = pokemonSchema.build(
  Formatter
).format(saved, { attributes: ['name', 'level'] })

You can use the FormattedValue type to explicitly type an object as a formatting output object:

import type { FormattedValue } from 'dynamodb-toolbox/format'

const formattedValue: FormattedValue<
  typeof pokemonSchema,
  // 👇 Optional options
  { partial: false; attributes: 'name' | 'level' }
  // ❌ Throws a type error
> = { invalid: 'output' }