tests for irb lexer

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57453 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/irb/test_ruby-lex.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: false
+require 'test/unit'
+require 'irb/ruby-lex'
+
+module TestIRB
+  class TestRubyLex < Test::Unit::TestCase
+    def setup
+      @scanner = RubyLex.new
+    end
+
+    def test_set_input_proc
+      called = false
+      @scanner.set_input(self) {|x| called = true; nil}
+      assert_nil(@scanner.lex)
+      assert(called)
+    end
+  end
+end