[ruby/yarp] Fix test-unit API in fuzzer test

https://github.com/ruby/yarp/commit/d24f62566e

test/yarp/fuzzer_test.rb

@@ -2,27 +2,25 @@
 
 require_relative "test_helper"
 
-# These tests are simply to exercise snippets found by the fuzzer that caused invalid memory access.
-class FuzzerTest < Test::Unit::TestCase
-  class << self
-    def snippet(name, source)
-      test "fuzzer #{name}" do
-        YARP.dump(source)
-      end
+module YARP
+  # These tests are simply to exercise snippets found by the fuzzer that caused invalid memory access.
+  class FuzzerTest < Test::Unit::TestCase
+    def self.snippet(name, source)
+      define_method(:"test_fuzzer_#{name}") { YARP.dump(source) }
     end
-  end
 
-  snippet "incomplete global variable", "$"
-  snippet "incomplete symbol", ":"
-  snippet "incomplete escaped string", '"\\'
-  snippet "trailing comment", "1\n#\n"
-  snippet "comment followed by whitespace at end of file", "1\n#\n "
-  snippet "trailing asterisk", "a *"
-  snippet "incomplete decimal number", "0d"
-  snippet "incomplete binary number", "0b"
-  snippet "incomplete octal number", "0o"
-  snippet "incomplete hex number", "0x"
-  snippet "incomplete escaped list", "%w[\\"
-  snippet "incomplete escaped regex", "/a\\"
-  snippet "unterminated heredoc with unterminated escape at end of file", "<<A\n\\"
+    snippet "incomplete global variable", "$"
+    snippet "incomplete symbol", ":"
+    snippet "incomplete escaped string", '"\\'
+    snippet "trailing comment", "1\n#\n"
+    snippet "comment followed by whitespace at end of file", "1\n#\n "
+    snippet "trailing asterisk", "a *"
+    snippet "incomplete decimal number", "0d"
+    snippet "incomplete binary number", "0b"
+    snippet "incomplete octal number", "0o"
+    snippet "incomplete hex number", "0x"
+    snippet "incomplete escaped list", "%w[\\"
+    snippet "incomplete escaped regex", "/a\\"
+    snippet "unterminated heredoc with unterminated escape at end of file", "<<A\n\\"
+  end
 end