Version

3.1.6

Reproduction link

http://shorturl.at/ixJQ5

Steps to reproduce

this.$router.push({
    ...this.$route, 
    params: {
        newParam: true
    }
})

With typescript, it breaks.

What is expected?

Route and Location types are compatible.

What is actually happening?

As Route now have the name parameter with string | null | undefined it breaks the navigation, as Location will only accept string | undefined as name.

Commit causing the issue:
8f831f2