tools/internal/tool: refactor tool.Main() for testabilty

In it previous implementation, tool.Main was meant to be called from
an applications main().  If it encountered an error it would print the
error to standard error and exit with a non-zero status (2).

It is also called recursively and in various test functions.

Exiting on an error makes testing difficult, unnecessarily.

This change breaks the functionality into to parts: an outer
tool.MustMain() that is intended to be called by main() functions and
an inner Main that is used by MustMain() and by test functions.

None of the existing test functions use Main()'s error value, but the
failure case tests for the command line invocation of rename (#194878)
require it.

Fixes #34291

Change-Id: Id0d80fc4670d56c87398b86b1ad9fdf7a676c95b
GitHub-Last-Rev: cd64995c91c94b997754c8d8b1004afc488bf8b7
GitHub-Pull-Request: golang/tools#159
Reviewed-on: https://go-review.googlesource.com/c/tools/+/195338
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
6 files changed
tree: c99c399484614403b6a4698ff0e34afe502e986e
  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.