I prefer the latter to the former... :)

output

Assertion with == failed
  code: Words.count("co-operative") == expected
  lhs:  %{"co" => 1, "operative" => 1}
  rhs:  %{"co-operative" => 1}

Assertion with == failed
  code: Words.count("co-operative") == %{"co-operative" => 1}
  lhs:  %{"co" => 1, "operative" => 1}
  rhs:  %{"co-operative" => 1}
  
  

reads_better.exs

test "hyphens" do                                                                
  expected = %{"co-operative" => 1}
  assert Words.count("co-operative") == expected
end

test "hyphens" do                                                                
  assert Words.count("co-operative") == %{"co-operative" => 1}
end