Run go test, using grc for colorizing, make and vim-test

conf.gotest

regexp==== RUN .*
colour=blue
-
regexp=--- PASS: .*
colour=green
-
regexp=^PASS$
colour=green
-
regexp=^(ok|\?) .*
colour=default
-
regexp=^\s*panic: .*
colour=red
-
regexp=--- FAIL: .*
colour=bold red
-
regexp=[^\s]+\.go(:\d+)?
colour=cyan

config.vim

" This is the config for vim-test. I use this plugin
" https://github.com/embear/vim-localvimrc for local project config.

" In addition to make I like using grc so that go tests are colorized.
let test#go#gotest#executable = 'grc make test'

function! MakeTransform(cmd) abort
  let l:args = substitute(a:cmd, g:test#go#gotest#executable." ", "", "")
  " echo "args: ".l:args

  " This is fun:
  " Running the nearest test in go uses the `-run='Test_Name$'` format.
  "
  " We want those to run from make, But since the dollar sign has a special
  " meaning in make, we need to scape it. To do that we need to use $$ instead
  " of $.
  "
  " Since the $ sign also has a meaning in the shell, we need those to be \$\$
  " instead.
  "
  " And then, since the substitution is done with Vim... I don't even know how
  " this worked, made it through test and error and it ended up working like
  " this.
  let l:escaped = substitute(l:args, "\\\$", "\\\\\\$\\\\\\$", "g")
  " echo "escaped: ".l:escaped

  " There's an example Makefile on the gist explaining this :D
  let l:final = 'TEST_ARGS="'.l:escaped.'"'
  " echo "final: ".l:final

  return g:test#go#gotest#executable." ".l:final
endfunction

let g:test#custom_transformations = {'make': function('MakeTransform')}
let g:test#transformation = 'make'

grc.conf

# https://github.com/garabik/grc

# Go test
\bgo.* test\b
conf.gotest

# Go test through make
\bmake test.*\b
conf.gotest

Makefile

# Build the test command allowing to overwrite some of the options.
TEST_FLAGS?=-v -race -count 1 -timeout 3s
TEST_ARGS?=./...
GO_TEST=go test $(TEST_FLAGS)

.PHONY: test
test:
	$(GO_TEST) $(TEST_ARGS)