go/packages: handle an overlay edge case with test variants

As usual, in debugging the creation of a new file with gopls, I've
encountered a go/packages overlay bug. The issue is:

A file b/b.go with package name "b" exists on disk. A package
b/b_test.go with no content exists on disk. There is an overlay for
b/b_test.go that contains the package name "b". Running packages.Load
for file=b/b_test.go will result in a failure to load package b
[b.test]. This change adds this test to the go/packages tests.

This case is fixed by restricting the fallback logic in
runContainsQueries. We only attempt to construct an ad-hoc package if
the original package was returned with no GoFiles.

Also, a minor change to the gopls error parsing code that fixes a case
in which diagnostics were being sent without corresponding files.

Updates golang/go#36635.

Change-Id: I38680a2cc65ae9c3252294db6b942d031189faf5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215743
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
4 files changed
tree: c350ea5aad7994d2c9825706fe3baef551e8ed23
  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. txtar/
  15. .gitattributes
  16. .gitignore
  17. AUTHORS
  18. codereview.cfg
  19. CONTRIBUTING.md
  20. CONTRIBUTORS
  21. go.mod
  22. go.sum
  23. LICENSE
  24. PATENTS
  25. 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.