go/packages/packagestest: add package use example

The purpose and value of packagestest is easy to understand. However,
the current API may not be easy to get started with. It includes
identifiers such as Exporter, Exported, Export, whose names may not
make it very clear in what order they are to be used, and whether
the Exporter interfaces needs to be implemented by the caller.

There are fairly common patterns of usage spread out across various
packages that use packagestest. Add an example of basic usage to the
documentation of this package that connects all of the pieces together,
so that users don't have to look for it elsewhere.

I would've preferred to add the example as example code¹, but it
doesn't seem viable to write example code for test helper packages.
There isn't a way to get a functional *testing.T in a func Example.

¹ https://golang.org/pkg/testing/#hdr-Examples

Updates golang/go#33655

Change-Id: I0b15ff7974be25a71dfd4b68f470441ce7331d18
Reviewed-on: https://go-review.googlesource.com/c/tools/+/196980
Reviewed-by: Michael Matloob <matloob@golang.org>
1 file changed
tree: d69e3811b761f51e5de42a7548f7611f7ca99a3d
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. go.mod
  21. go.sum
  22. LICENSE
  23. PATENTS
  24. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.