Support -> { ... }.should.raise(SomeException, "message", cause:)

* Like `should raise_error(SomeException, "message", cause:)`
  but using the `should.` syntax.

Author: eregon

lib/mspec/matchers/base.rb

@@ -36,6 +36,14 @@ def equal?(expected)
     end
   end
 
+  def raise(exception = Exception, message = nil, options = nil, &block)
+    matcher = ::RaiseErrorMatcher.new(exception, message, options, &block)
+    unless matcher.matches? @actual
+      expected, actual = matcher.failure_message
+      ::SpecExpectation.fail_with(expected, actual)
+    end
+  end
+
   def method_missing(name, *args, &block)
     result = @actual.__send__(name, *args, &block)
     unless result
@@ -70,6 +78,14 @@ def equal?(expected)
     end
   end
 
+  def raise(exception = Exception, message = nil, options = nil, &block)
+    matcher = ::RaiseErrorMatcher.new(exception, message, options, &block)
+    if matcher.matches? @actual
+      expected, actual = matcher.negative_failure_message
+      ::SpecExpectation.fail_with(expected, actual)
+    end
+  end
+
   def method_missing(name, *args, &block)
     result = @actual.__send__(name, *args, &block)
     if result