only use GEMNAME if defined in assert.rb
Check if the constant GEMNAME is defined before use in `assert.rb`.
This is added to prevent an undefined constant error when using
`assert.rb` in other environments - for example, testing CRuby.
MODIFY
test/assert.rb
test/assert.rb
@@ -56,7 +56,9 @@ def assertion_string(err, str, iso=nil, e=nil, bt=nil)
msg = "#{err}#{str}"
msg += " [#{iso}]" if iso && !iso.empty?
msg += " => #{e}" if e && !e.to_s.empty?
+ if Object.const_defined?(:GEMNAME)
msg += " (#{GEMNAME == 'mruby-test' ? 'core' : "mrbgems: #{GEMNAME}"})"
+ end
if $mrbtest_assert
$mrbtest_assert.each do |idx, assert_msg, diff|
msg += "\n - Assertion[#{idx}]"

only use GEMNAME if defined in assert.rb

Check if the constant GEMNAME is defined before use in `assert.rb`.

This is added to prevent an undefined constant error when using
`assert.rb` in other environments - for example, testing CRuby.