Calling toNumber() on a unitless unit (math.Unit instance) causes an error

[pedroasad]

Using mathjs@6.6.2

The math.unit() constructor allows for unitless quantities, that is, specifying a value without a unit name, like math.unit(3). However, objects instantiated like this cause an error when the toNumber() metho is called.

Minimal steps to reproduce (no Node.js console):

> const math = require('mathjs')
> const x = math.unit(3)
> x.toNumber()  // expected result is 3
TypeError: Cannot read property 'prefix' of undefined
    at Unit.toNumeric (<working_dir>/node_modules/mathjs/lib/type/unit/Unit.js:914:61)
    at Unit.toNumber (<working_dir>/node_modules/mathjs/lib/type/unit/Unit.js:891:26)

The error seems to happen on src/type/unit/Unit.js:886.

[josdejong]

Thanks for reporting Pedro. I've created a PR with a fix in #1811. @ericman314 can you have a look please?

[josdejong]

This issue is fixed now in mathjs@6.6.3