[scm] Don't try to parse invalid ls-files output

If an error occurred on the `ls-files` command or a previous git
command, `g.err` will be set and will cause subsequent `g.run()` calls
to short-circuit and return an empty string. Trying to parse an empty
string using the ls-files parsing logic causes panics, so we must skip
it if an error occurred.

This was causing confusing panics when a check failed before `git
ls-files` was called for the first time.

Change-Id: Ice428fc83ecd9e7566e74c3ff85e03635676ff19
Reviewed-on: https://fuchsia-review.googlesource.com/c/shac-project/shac/+/916074
Reviewed-by: Anthony Fandrianto <atyfto@google.com>
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
1 file changed
tree: 77e44a6c62eec79b9ea6f337ce45c8df49552dc2
  1. .github/
  2. checks/
  3. doc/
  4. images/
  5. internal/
  6. scripts/
  7. vendor/
  8. .gitignore
  9. AUTHORS
  10. codecov.yml
  11. CONTRIBUTING.md
  12. go.mod
  13. go.sum
  14. LICENSE
  15. main.go
  16. OWNERS
  17. PATENTS
  18. README.md
  19. shac.star
  20. shac.textproto
README.md

shac

Shac (Scalable Hermetic Analysis and Checks) is a unified and ergonomic tool and framework for writing and running static analysis checks.

Shac checks are written in Starlark.

usage demonstration

Usage

go install go.fuchsia.dev/shac-project/shac@latest
shac check
shac doc shac.star | less

Documentation

Road map

Planned features/changes, in descending order by priority:

  • [x] Configuring files to exclude from shac analysis in shac.textproto
  • [x] Include unstaged files in analysis, including respecting unstaged shac.star files
  • [x] Automatic fix application with handling for conflicting suggestions
  • [ ] Provide a .shac cache directory that checks can write to
  • [ ] Mount checkout directory read-only
    • [x] By default
    • [ ] Unconditionally
  • [ ] Give checks access to the commit message via ctx.scm
  • [ ] Built-in formatting of Starlark files
  • [ ] Configurable “pass-throughs” - non-default environment variables and mounts that can optionally be passed through to the sandbox
  • [ ] Add glob arguments to ctx.scm.{all,affected}_files() functions for easier filtering
  • [ ] Filesystem sandboxing on MacOS
  • [ ] Windows sandboxing
  • [ ] Testing framework for checks

Contributing

⚠ The source of truth is at https://fuchsia.googlesource.com/shac-project/shac.git and uses Gerrit for code review.

See CONTRIBUTING.md to submit changes.