io-ts-reporters

Error reporters for
io-ts.

!scarf-downloads

Currently this package only includes one reporter. The output is an array of
strings in the format of:

``
Expecting ${expectedType} at ${path} but instead got: ${actualValue}
`

And for union types:

`
Expecting one of:
${unionType1}
${unionType2}
${...}
${unionTypeN}
at ${path} but instead got: ${actualValue}
`

Installation

`bash
yarn add io-ts-reporters
`

Example

`ts
import * as t from 'io-ts'
import reporter from 'io-ts-reporters'

const User = t.interface({name: t.string})

// When decoding fails, the errors are reported
reporter.report(User.decode({nam: 'Jane'}))
//=> ['Expecting string at name but instead got: undefined']

// Nothing gets reported on success
reporter.report(User.decode({name: 'Jane'}))
//=> []
`

To only format the validation errors in case the validation failed (ie.
mapLeft) use formatValidationErrors instead.

`ts
import * as t from 'io-ts'
import {formatValidationErrors} from 'io-ts-reporters'
import * as E from 'fp-ts/Either'
import {pipe} from 'fp-ts/pipeable'

const User = t.interface({name: t.string})

const result = User.decode({nam: 'Jane'}) // Either

E.mapLeft(formatValidationErrors)(result) // Either
`

For more examples see the tests.

TypeScript compatibility

| io-ts-reporters version | required typescript version |
| ----------------------- | --------------------------- |
| 1.0.0 | 3.5+ |
| <= 0.0.21 | 2.7+ |

Testing

`bash
yarn
yarn run test
``

[io-ts]: https://github.com/gcanti/io-ts#error-reporters

Credits

This library was created by OliverJAsh.