test/envutil: port assert_raise_with_message from Ruby tree

Ruby's assert_raise doesn't allow the expected exception to be an
instance of an exception.

1 files changed, 50 insertions, 0 deletions

diff --git a/test/envutil.rb b/test/envutil.rb
index a4964c2c..5cd8b511 100644
--- a/test/envutil.rb
+++ b/test/envutil.rb
@@ -576,6 +576,56 @@ eom
         values
       end
 
+      # :call-seq:
+      #   assert_raise_with_message(exception, expected, msg = nil, &block)
+      #
+      #Tests if the given block raises an exception with the expected
+      #message.
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      nil #Fails, no Exceptions are raised
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise ArgumentError, "foo" #Fails, different Exception is raised
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise "bar" #Fails, RuntimeError is raised but the message differs
+      #    end
+      #
+      #    assert_raise_with_message(RuntimeError, "foo") do
+      #      raise "foo" #Raises RuntimeError with the message, so assertion succeeds
+      #    end
+      def assert_raise_with_message(exception, expected, msg = nil, &block)
+        case expected
+        when String
+          assert = :assert_equal
+        when Regexp
+          assert = :assert_match
+        else
+          raise TypeError, "Expected #{expected.inspect} to be a kind of String or Regexp, not #{expected.class}"
+        end
+
+        ex = m = nil
+        EnvUtil.with_default_internal(expected.encoding) do
+          ex = assert_raise(exception, msg || "Exception(#{exception}) with message matches to #{expected.inspect}") do
+            yield
+          end
+          m = ex.message
+        end
+        msg = message(msg, "") {"Expected Exception(#{exception}) was raised, but the message doesn't match"}
+
+        if assert == :assert_equal
+          assert_equal(expected, m, msg)
+        else
+          msg = message(msg) { "Expected #{mu_pp expected} to match #{mu_pp m}" }
+          assert expected =~ m, msg
+          block.binding.eval("proc{|_|$~=_}").call($~)
+        end
+        ex
+      end
+
       class << (AssertFile = Struct.new(:failure_message).new)
         include Assertions
         def assert_file_predicate(predicate, *args)