@xerocross/data-is v1.3.0

Data-Is

An extremely simple utility for defining and validating data types. You can run the tests by executing npm run test. The tests are the official documentation.

Create an instance of DataIs using data = DataIs.build();.

You can define arbitrary data types so long as you can pass in a function that evaluates boolean to check whether any input passes or fails. The predicate defines the data type, such as data.define.type([typeName], [testFunction]).

Then you can test a particular element using the syntax data([data]).is.a([typeString]);.

There are no pre-defined types.