index.test.ts

import test from 'ava'
import * as iots from 'io-ts'
import {withMessage} from 'io-ts-types/lib/withMessage'

import Reporter, {TYPE_MAX_LEN} from '../src'

test('reports an empty array when the result doesn’t contain errors', (t) => {
  const PrimitiveType = iots.string
  const result = PrimitiveType.decode('foo')

  t.deepEqual(Reporter.report(result), [])
})

test('formats a top-level primitve type correctly', (t) => {
  const PrimitiveType = iots.string
  const result = PrimitiveType.decode(42)

  t.deepEqual(Reporter.report(result), ['Expecting string but instead got: 42'])
})

test('formats array items', (t) => {
  const NumberGroups = iots.array(iots.array(iots.number))
  const result = NumberGroups.decode({})

  t.deepEqual(Reporter.report(result), [
    'Expecting Array<Array<number>> but instead got: {}',
  ])
})

test('formats nested array item mismatches correctly', (t) => {
  const NumberGroups = iots.array(iots.array(iots.number))
  const result = NumberGroups.decode([[{}]])

  t.deepEqual(Reporter.report(result), [
    'Expecting number at 0.0 but instead got: {}',
  ])
})

test('formats branded types correctly', (t) => {
  interface PositiveBrand {
    readonly Positive: unique symbol
  }

  const Positive = iots.brand(
    iots.number,
    (n): n is iots.Branded<number, PositiveBrand> => n >= 0,
    'Positive',
  )

  t.deepEqual(Reporter.report(Positive.decode(-1)), [
    'Expecting Positive but instead got: -1',
  ])

  const PatronizingPositive = withMessage(
    Positive,
    (_i) => "Don't be so negative!",
  )

  t.deepEqual(Reporter.report(PatronizingPositive.decode(-1)), [
    "Expecting Positive but instead got: -1 (Don't be so negative!)",
  ])
})

test('truncates really long types', (t) => {
  const longType = iots.type({
    '1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890':
      iots.number,
  })
  const messages = Reporter.report(longType.decode(null))
  t.is(messages.length, 1)
  t.regex(
    messages[0],
    new RegExp(
      `^Expecting .{${TYPE_MAX_LEN - 3}}\\.{3} but instead got: null$`,
    ),
    'Should be truncated',
  )
})

test('doesn’t truncate really long types when truncating is disabled', (t) => {
  const longTypeName =
    '1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890'
  const longType = iots.type({
    [longTypeName]: iots.number,
  })
  const messages = Reporter.report(longType.decode(null), {
    truncateLongTypes: false,
  })
  t.is(messages.length, 1)
  t.is(
    messages[0],
    `Expecting { ${longTypeName}: number } but instead got: null`,
    'Should not be truncated',
  )
})