@bayou/typecheck

Subcomponent of the Bayou project.

Usage no npm install needed!

<script type="module">
  import bayouTypecheck from 'https://cdn.skypack.dev/@bayou/typecheck';
</script>

README

@bayou/typecheck

This module consists mostly of utility classes (just static methods), each of which is dedicated to doing type and content checking for values of a particular type. In order to disambiguate between these classes and the built-in classes for the same types, this module prefixes its classes with the capital letter T.

The main method of each type checker class is called check(), which always takes as its first argument the value to check and in some cases accepts additional options (as documented). These methods always either return a value of the class's type-in-question or throw an error, as follows:

  • If the input value is already of the type in question, that value is returned.

  • If the input value isn't of the type in question but the options allow for conversion or defaulting, then the return value is the converted / defaulted value.

  • Otherwise, an error is thrown with a message typically of the form "Expected value of type type."

In some cases, type checker classes have additional methods which perform variations of the type check. These are defined in cases where it would be confusing to overload the semantics of the main check() method.

Copyright 2016-2019 the Bayou Authors (Dan Bornstein et alia).
Licensed AS IS and WITHOUT WARRANTY under the Apache License,
Version 2.0. Details: <http://www.apache.org/licenses/LICENSE-2.0>