[MO-java-dev] Java Dynamic Mocks - going to Head?

[Tim M. <tim...@po...>]

Guys -

First of all, sorry for missing Xtc - I've got the dynamic bug and want to
see the library in a state that it can be used in many projects. I think its
important to convey the power and simplicity of mocks (we all know this, but
there are so many bad examples out there...).

Anyway - I tried using the branch in the e2x codebase and as always, on a
real project there are often little subtleties that catch you out. As John
Nolan was around working on his own little pet project we bounced ideas of
each other to get things done.

Anyway - the library is working out quite well now and we should consider
rolling it in to the head stream soom! (Maybe a day or two more of "in
usage" testing, and comments from anyone else who is interested - but to be
honest making it available in the head should allow greater changes).

Here are some points:

1) To test the dynamic stuff, we used Traditional Mocks - it became a pain
hand coding them, especially on larger interfaces, so we took the decision
to use MockMaker. This worked well, however their are some ReturnXXX objects
that it uses that should be in the base library. In the branch I have just
put them in - however they duplicate some existing functionality. I propse
we resolve this duplication in a second pass as it requires updates to code
that mockmaker generates. Having the additional duplication allows an
exisiting generated mock to be updated by simply removing 3 import lines. To
get a full solution we need to get all the tools running on a single
platform - and you use the right one for the right job.

2) The Callable interface has a "matches" method, this doesn't feel right
for all callables, its required for CallBag to operate - others don't need
it. This should be removed and implemented as a private decoration for
CallBag.

3) Steve's exellent suggestion of having:

Callable c1 = mock.expect("setContentType".....)
Callable c2 = mock.expect("getWriter".....)
c1.expectBefore(c2)

has not yet been implemented. This should work quite easily, but the focus
has been on UnorderdMock and OrderedMock.

4) As you can use mocks as expected values themselves - there was some
ugliness with the proxies needing to detect equality of mocks (you can see
this in the invoke method). I'm not sure if there is a better way to do
this.

5) I think Mocks should probably register with something so that we can do
the Verifier.verify on both instance variables and local variables in a
test. I am still seeing lots of accidently unverified mocks

Overall the sample test case is looking very good (I have included it again
below). How does everyone feel going ahead with a merge (I can probably get
Chris Cottee to help me merge it in at e2x)?

Tim

public void testDoGetNew() throws ServletException, IOException {
		Mock mockHttpServletResponse = new OrderedMock(HttpServletResponse.class,
"response");
		Mock mockHttpServletRequest = new Mock(HttpServletRequest.class);

		mockHttpServletRequest.matchAndReturn( "getParameter",
C.args(C.eq("browser-identifier")), "MSIE-5.0" );
		mockHttpServletRequest.expectAndReturn( "getParameter", "subject", "Mail
Subject" );
// Alternative syntax
		mockHttpServletRequest.expectAndReturn( "getParameter",
C.args(C.eq("body")), "Mail Body" );

		final PrintWriter contentWriter = new PrintWriter(new StringWriter());

		mockHttpServletResponse.expect( "setContentType", "text/html");
		mockHttpServletResponse.expectAndReturn( "getWriter", contentWriter );

// Still to do, instead of making response an OrderedMock
//		CallMatch m1 = mockHttpServletResponse.expect( "setContentType",
"text/html");
//		CallMatch m2 = mockHttpServletResponse.expectAndReturn( "getWriter",
C.args(), contentWriter );
//		m1.expectBefore(m2);

		SimpleServlet aServlet = new SimpleServlet();
		aServlet.doGet((HttpServletRequest) mockHttpServletRequest.proxy(),
(HttpServletResponse) mockHttpServletResponse.proxy());

		mockHttpServletRequest.verify();
		mockHttpServletResponse.verify();
	}
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