switch tests to use github.com/google/go-cmp package

[willnorris]

#1846 calls out not using reflect.DeepEqual for comparing error values, but in reality we shouldn't be using it all. https://pkg.go.dev/github.com/google/go-cmp/cmp is designed to be a much safer alternative, so we should use that for tests.

[willnorris]

and just to be clear, we should use go-cmp for all of our non-error values (of which there appear to be 600+ comparisons?!). Switching to go1.13's errors.Is is the right change for errors.

[photongupta]

@willnorris Can I start working on this?

[willnorris]

have at it! (With so many instances, you might want to do a global find and replace, or use gofmt -r)

[sagar23sj]

Hi @photongupta. Are You Still working on this issue.
I would also like to contribute.