minitest no test run

[Javix]

I can't figure out why the following Rakefile:

require 'rake/testtask'

task default: :test

Rake::TestTask.new do |t|
  t.libs << %w(test lib)
    t.pattern = "test/test_*.rb"
end

see no test test files when running rake from the root of the project:

minitest-project
 - lib
   - meme.rb
 - test
   - test_meme.rb
   - test_helper.rb

here the content of test_helper.rb:

require 'minitest/autorun'
require 'minitest/reporters'

Minitest::Reporters.use! Minitest::Reporters::SpecReporter.new # spec-like progress

When running rake:

Run options: --seed 54795

# Running tests:



Finished tests in 0.004000s, 0.0000 tests/s, 0.0000 assertions/s.

0 tests, 0 assertions, 0 failures, 0 errors, 0 skips

Minitest version: minitest (5.5.0, 4.7.5)
Ruby version: ruby 2.1.5p273 (2014-11-13 revision 48405) [x64-mingw32]

Any idea ?
Thank you

[Javix]

I forgot to post the content of the test class TestMeme :

require 'test_helper'
require 'meme'

class TestMeme < Minitest::Test
  def setup
    @meme = Meme.new
  end

  def test_that_kitty_can_eat
    assert_equal "OHAI!", @meme.i_can_has_cheezburger?
  end

  def test_that_it_will_not_blend
    refute_match /^no/i, @meme.will_it_blend?
  end

  def test_that_will_be_skipped
    skip "test this later"
  end
end