Extended expect syntax and more

[horkhe]

With this patch I would like to suggest the following changes:

1. Previously sequences of return values could be defined through special sequence and loop functions. This patch introduces an alternative syntax that allows defining return specifications right in the expect function. Consider:

   meck:expect(Mod, f, 1, meck:val(a)), % equivalent to meck:expect(Mod, f, 1, a) ?assertEqual(a, Mod:f(1001)), ?assertEqual(a, Mod:f(1001)),

   meck:expect(Mod, f, 1, meck:seq([a, b])), ?assertEqual(a, Mod:f(1001)), ?assertEqual(b, Mod:f(1001)), ?assertEqual(b, Mod:f(1001)),

   meck:expect(Mod, loop, 1, meck:loop([a, b])), ?assertEqual(a, Mod:loop(1001)), ?assertEqual(b, Mod:loop(1001)), ?assertEqual(a, Mod:loop(1001)),

2. Previously expectations can be defined either as func-name/arity or as func-name/anon-func. This patch introduces the third way which is defining an expectations through a list of arg pattern/values just like defining an ordiry function but shorter. Consider:

   meck:expect(Mod, f, [{[1, 1], a}, {[1, ''], b}, {['', '_'], c}]), ?assertEqual(a, Mod:f(1, 1)), ?assertEqual(b, Mod:f(1, 2)), ?assertEqual(c, Mod:f(2, 2)).

3. Combining return specifications and argument patterns you can create quite sophisticated expectations. Consider:

   meck:expect(Mod, f, [{[1, 1], meck:seq([a, b, c])}, {[1, ''], meck:loop([d, e])}, {['', '_'], meck:val(f)}]), ?assertEqual(d, Mod:f(1, 2)), ?assertEqual(f, Mod:f(2, 2)), ?assertEqual(e, Mod:f(1, 2)), ?assertEqual(a, Mod:f(1, 1)), ?assertEqual(d, Mod:f(1, 2)), ?assertEqual(b, Mod:f(1, 1)), ?assertEqual(c, Mod:f(1, 1)), ?assertEqual(f, Mod:f(2, 2)), ?assertEqual(c, Mod:f(1, 1)), ?assertEqual(e, Mod:f(1, 2)), ?assertEqual(c, Mod:f(1, 1)).

4. Besides internal data structure redesign made in the scope of this patch allows easier introduction of hamcrest patterns into the expectation definition.

Adam, please consider this changes and provide your comments.

[horkhe]

I did rebase and squashed changes to one commit for your convenience.

[eproxus]

I like this, a lot!

[horkhe]

@eproxus, I removed rebar.config and .gitignore changes from the original commit and that whipped out almost all your comments. Fortunately I managed to address all of them anyway. Please take a look.

[horkhe]

@eproxus have you had a chance to take a look at the changes?

[eproxus]

Sorry for the late reply. I'm planning to pull this in ASAP, I'll keep you posted.

[horkhe]

@eproxus just want to let you know that I've got another pull request coming that is based on this one. It will introduce 'honest' mocks that is mocks that allow you to create expectations for exported functions only. That will for example make your unit test fail if a module, mocked in your unit test, was updated to add a new parameter to a function that you have expectations for, hereby detecting the fact that you forgot to update your module and unit test earlier.

[travisbot]

This pull request passes (merged 12c2dea0 into beb8d14e).

[eproxus]

Also, you've managed to make creation of expect functions faster. :+1:

Before:

1> meck_performance_test:run(10000).
                Min     Max     Med     Avg
expect/3        1246    3435    1370    1409
expect/3+args   1939    7537    2253    2547
expect/4        2291    5497    2446    2474
expect/4+args   2797    6436    2950    3002

                Min     Max     Med     Avg
normal          8       682     9       10
normal_args     8       1652    9       10
shortcut        0       21      1       1
shortcut_args   0       36      1       1
shortcut_opaque 8       1545    9       11

                Min     Max     Med     Avg
called          19      135     20      21

After:

1> meck_performance_test:run(10000).
                Min     Max     Med     Avg
expect/3        1195    3732    1275    1289
expect/3+args   1825    5115    1980    2012
expect/4        2019    5271    2142    2187
expect/4+args   2385    6972    2539    2607

                Min     Max     Med     Avg
normal          9       648     10      10
normal_args     9       1591    10      11
shortcut        9       276     9       10
shortcut_args   9       304     10      10
shortcut_opaque 9       4777    10      12

                Min     Max     Med     Avg
called          19      75      20      22

Note however that the "shortcut" versions of the expects (e.g. meck:expect(M, F, 1, ok)) are slower (they were previously compiled into the mock module itself (there are a few lines of coverage missing around 689 and 710). It's not terribly important right now, and I also realized that with the ArgsPattern structure there will be even more opportunities for code generation.

[travisbot]

This pull request passes (merged 92b8ae37 into beb8d14e).

[horkhe]

Glad to hear about the performance though it was not intentional. I addressed the most of your comments as good as I could manage at such late hour :)

[travisbot]

This pull request passes (merged fa0eb68b into beb8d14e).

[horkhe]

Seems like this is it :)

[travisbot]

This pull request passes (merged de63a05a into beb8d14e).

[horkhe]

@eproxus I do not want to sound pushy but is it possible to speed up code inspection a little? I have got 3 more pull requests coming.

[eproxus]

Sorry for the incredibly long lag on my responses. I've now merged this into develop so we can let it brew for a while. Nice work! :-)

[horkhe]

Thanks! ...to be continued :-)