tree 8bf5b4b9b2c551e815eba7f6a60ba44bbdf8c6c2
parent 15ad1aa0cbfab7f8ca1631cbff233055bce788bc
author Heschi Kreinick <heschi@google.com> 1540849102 -0400
committer Heschi Kreinick <heschi@google.com> 1541620385 +0000

imports: create named imports for name/path mismatches

For clarity and performance reasons, we want the fast path of goimports
to be purely syntactic. Packages whose import paths don't match their
package names make this harder. Before this CL, we parsed each imported
package to get its real package name. Now, we make named imports for
such packages, and on subsequent runs we don't have to do the extra
work.

A package name matches its import path if the name is the last segment
of the path, or the next-to-last before a version suffix vNN. gopkg.in
style .vNN suffixes are considered mismatching.

goimports already had almost exactly the desired logic, but only when
adding a new import. So the bulk of this change is simply removing the
logic that allowed it to recognize that a mismatched import satisfied
some uses. With that gone, it will remove those imports as unused, then
add a new renamed import. Some comments may be destroyed.

Fixes golang/go#28428

Change-Id: I53846e6046affb420f41719f84c71086c5b9e5e6
Reviewed-on: https://go-review.googlesource.com/c/145699
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>