Yet another validation framework

Usage no npm install needed!

<script type="module">
  import validish from '';



A framework[ish] to check if data is valid[ish]

I didn't have time to look for one that satisfied all of my needs, so I wrote one for a project and extracted the code.


  • See issues


  • Support IE8

Requirements (where this is/was going)

These don't mean the validish would support all of these features, not in the core anyways, however these are the things one needs to care about, when creating a project with a decent[ish] UX.

  • Parameterized messages / i18n
  • Validation context: other form data; user status
  • Async only
  • Validate one field to display in UI while the user is typing
  • Re-validate one field to display in UI after the user finished typing (blur)
  • Validate one field based on value of another field (e.g. compare passwords, price mandatory for offers)
  • Emptiness is an error during/after submit, but not during typing
  • Parallel validation - e.g. check length and regex at the same time
  • Sequential validation - e.g. only check regex if not empty
  • Validate all fields in UI before submit
  • Validate all fields on server side
  • UI: jump to error field during submit if invalid
  • UI: field state - invalid, valid, warning, checking
  • Async validation of field may finish than the validation of the same field as part of the form - needs to be handled
  • fieldValidationResult = f(value, context, config)
  • Co-dependent fields (e.g. isOffer=yes/no vs price required)


I currently have no idea what these scribbles were meant to be, but they were there.

  • describe fields
  • describe generic validators for fields
  • inject specific validators for fields
  • run validation on the object
  • client side: run validation on field
  • client side: run validation on all fields, but ensure existing validations get finished