In spite of https://blog.golang.org/examples and
http://golang.org/pkg/testing/#pkg-examples, a number of internal Go
authors have found writing documentation examples to be problematic in
the sense that the syntax is error-prone due to loose coupling with
identifiers found in the source corpus.
This commit introduces a suite of validations for documentation
examples:
Overall:
- Correct suffices, if present
- Niladic function argument and return signatures
func Example() {}
func ExampleF() {}
- F exists
func ExampleT() {}
- T exists
func ExampleT_M() {}
- T exists
- M exists within T
Further, if the example is in `package foo_test`, vet attempts to
resolve the respective lookups in `package foo`, if `package foo`
exists (cf., `package stringutil_test`).
Change-Id: Ifa13906363541ebf28325681b749b14b7f8b103d
Reviewed-on: https://go-review.googlesource.com/11982
Reviewed-by: Andrew Gerrand <adg@golang.org>
a25a8d567b