parseParams doesn't handle empty or null case

[OnurGumus]

Description

I am seeing this line throws when used via Navigation when query string is null. It assumes queryString has some value

https://github.com/elmish/urlParser/blob/014ab69bd9cb13cbfa743d2625a658460641b7f0/src/parser.fs#L357

It just looks wrong to me.

Related information

• elmish version: 4.0
• fable-compiler version: 4.0
• fable-core version: 4.0
• Operating system: macos

[et1975]

Released the changes in 1.0.1.