[RFC] Add a "go-unit-tests" hook

[cshamrick]

Adding this RFC on behalf of @jduclos-bellese - we'd like to get feedback about whether we could add a go-unit-tests hook to this project. We could implement the hook similar to the go-unit-tests hook found in dnephin/pre-commit-golang, which executes a bash script like this:

#!/usr/bin/env bash
FILES=$(go list ./...  | grep -v /vendor/)

go test -tags=unit -timeout 30s -short -v ${FILES}

returncode=$?
if [ $returncode -ne 0 ]; then
  echo "unit tests failed"
  exit 1
fi

[phillipjf]

This example script is pretty opinionated. We should decide if it's the opinion we want to enforce or if there's a better way to allow configuration on how to run tests. There's only a few issues on the original project but one already asks for a different way to do tests: dnephin/pre-commit-golang#49

This suggests all tests to be tagged unit via Build Constraints. What if a project does not tag their tests? Or already uses another tag for managing tests?

If there really is a good "standard" for tests, we could drive towards that but I think, generally, any implementation may end up being too opinionated, and therefore, unused.

[cshamrick]

@phillipjf would it be of value to implement a generic, configurable/overridable solution for this? e.g.:

The default just runs tests without tags, etc.:

repos:
 - repo: git://github.com/bellese/pre-commit-golang
   rev: master
   hooks:
     - id: go-unit-tests

Or with -tags and -timeout:

repos:
 - repo: git://github.com/bellese/pre-commit-golang
   rev: master
   hooks:
     - id: go-unit-tests
       args: [-tags=unit, -timeout=30s]