Running minitest without Rake

Nov 11, 2024 TIL Rating: good-to-know

When it’s about writing tests for a Ruby project, I prefer minitest to anything else. It’s fast and doesn’t require to switch mental context to any domain-specific language (DSL). It’s just Ruby.

Because minitest allows to express tests using plain Ruby, Ruby is the only necessary tool to run those tests.

$ ruby -Ilib:test test/foo/test_foo_test.rb

Running minitest tests with Ruby.

That works fine for one file, but a bit tricky for multiple test files at once.

minitest comes with a Rake task to run all tests. However for small projects it might be to much to bring Rake just for that case.

So I wrote a script to run tests without anything but Ruby. It’s basically a wrapper around a test runner that comes with minitest.

#!/usr/bin/env -S ruby -Ilib:test:.

# Sets up the environment and runs minitest.
#
# Syntax
#
#   minitest [options] file [file ...]
#
# Examples
#
#   minitest test/**/*test.rb
#
#   minitest --help
#
#   minitest test/**/*test.rb --verbose
#
#   minitest test/**/*test.rb --seed 123

files = []

# Extract file paths from ARGV and keep only command-line options.
# Minitest::autorun depends on values in ARGV, but expects only options there.

ARGV.delete_if do |arg|
  keep = arg.end_with?(".rb")
  files.push(arg) if keep
  keep
end

# Require all test files because they will be later used by the minitest runner.

files.each { |f| require(f) }

# If no command-line arguments have been given, print help.

ARGV.push("--help") if files.empty? && ARGV.empty?

# Let minitest autorunner to do its job.
# At this point the environment is setup and ready for tests to be executed.

require "minitest/autorun"

${HOME}/.local/bin/minitest

The script sets up an environment and calls the minitest runner. No magic.

$ minitest test/**/*_test.rb
Run options: --seed 6995

# Running:

.....

Finished in 0.001306s, 3829.5571 runs/s, 7659.1143 assertions/s.

5 runs, 10 assertions, 0 failures, 0 errors, 0 skips

All command-line options of the minitest runner are available as well:

$ minitest --help
  minitest options:
    -h, --help                       Display this help.
        --no-plugins                 Bypass minitest plugin auto-loading (or set $MT_NO_PLUGINS).
    -s, --seed SEED Sets random seed. Also via env. Eg: SEED=n rake
    -v, --verbose Verbose. Show progress processing files.
    -q, --quiet Quiet. Show no progress processing files.
        --show-skips Show skipped at the end of run.
    -n, --name PATTERN Filter run on /regexp/ or string.
    -e, --exclude PATTERN Exclude /regexp/ or string from run.
    -S, --skip CODES Skip reporting of certain types of results (eg E).
    -W[error] Turn Ruby warnings into errors

  Known extensions: pride
    -p, --pride Pride. Show your testing pride!

Running minitest without Rake

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