Add raw string compare in doctests for #Module<...>

[ericmj]

Will now do raw string compare for doctests of #Module<...> format:

iex> HashDict.new a: 0, b: 1, c: 2
#HashDict<[a: 0, b: 1, c: 2]>

[ericmj]

This may look like a hack but the resulting error message is really nice:

     ** (ExUnit.ExpectationError)
       expected doctest: inspect (HashDict.new d: 3, e: 4, f: 5)
         to evaluate to: "#HashDict<[a: 0, b: 1, c: 2]>"
            instead got: "#HashDict<[d: 3, e: 4, f: 5]>"

You see exactly what is happening.

[josevalim]

Looks nice. We just need to remove the space in between inspect and ( or get rid of parentheses.

[ericmj]

Forgot docs, hold on.

[ericmj]

Added docs.

[meh]

👍

[vendethiel]

Seems to have a typo "<[" closed as "]"

[ericmj]

@Nami-Doc Thank you. Apparently the DocTest module isn't doctested, go figure.

I also made Version use the new feature. Any other modules that may use this?

[josevalim]

@Nami-Doc @ericmj the doctest module has example of bad doc tests and that would make it fail. :P

[josevalim]

Why are we stripping? I don't think it is a good idea. Imagine this:

iex> """
...>   hello
...> """

[ericmj]

There was actually a problem with just prepending the expression string with "inspect " for expressions that span multiple lines or expressions that have multiple statements (for example assignment). So instead I added a new :inspect test case.