assert_debug_eq gives unexpected results with `expect_file`

[jberryman]

I think... or maybe I don't understand the docs.

If I do expect_file![path].assert_eq(&actual) in diff below I get the green case, while assert_debug_eq gives red. I was expecting the latter to result in a file with indentation and newlines so it can be read. The docs say "leading indentation is automatically removed", but I'm not sure what that means