Lifecycle/space fixups #519

myronmarston · 2014-01-04T04:32:01Z

This is the start of addressing a bunch of issues.

Fixes #165 -- stop resetting mock proxies twice at the end of each example
Fixes #352 -- make test doubles self-destruct after they are torn down.
Fixes #240 -- adds with_temporary_scope.

Ready for review.


        Remove test we no longer need.

The logic that required this test was removed in cd81094.


        Stop double-resetting mock proxies.

We don't need to reset the mock proxy while verifying it. That'll happen later during the teardown phase. It looks like the main reason we were doing this was to assist with rspec-mocks testing itself; we would verify the middle of an example to assert a mock expectation failure, and a `reset` is needed so it doesn't fail again when rspec-core calls `verify` as well. The solution is to use spec helper methods that perform the reset when we verify in the middle of an example. I don't have any evidence this improves perf, but it seems reasonable to assume that removing an extra method call per example can only make it faster (however slight the improvement may be). Fixes #165.


        Make test doubles self-destruct after the example completes.

Test doubles are not designed to be used outside of the example they were created in.


        Update spec to only specify the behavior we are keeping.

We're going to change the behavior of test doubles that have been reset (so that they "expire" and can no longer be used). This spec was originally added in 847c66d where the point was to address an error while resetting a test double (which, in turn caused that method double to stick around into later examples and continue to fail).


        Split spec into two.

The second part of this spec was added in 9357e4d. We are changing test doubles so that they self-destruct after being reset. Currently, `verify` also resets, so verifying a test double twice will no longer be allowed.


        Update teardown spec.

We're going to change how pure test doubles behave after teardown, so update this to focus on partial doubles (which will not be changed).


        No need for ProxyForNil to have its own file.


        Centralize error classes in error_generator.rb.

Also, document some of them as public since users may want to rescue them, or specify a block will raise one of these errors (e.g. in an rspec-mocks extension gem).


        Move error_space.rb into space.rb

There's no need for a separate file and there's going to be a bit of interaction between multiple spaces at various layers in a stack so having it in one file will make it easier to see how it relates.


        Remove an unnecessary layer of indirection.

* This should be faster (but almost certainly not noticably so). * It was odd to expose these methods off of `RSpec::Mocks` given that they are not intended for usage outside rspec-mocks. * We weren't getting any benefit from these except for not having to type `.space`.

penelopezone · 2014-01-04T19:42:52Z

@myronmarston I took a look through this. Looks good :)


        Refactor: store const mutators in mock space.

This unifies global storage of modified things in one place.


        Re-work spec file a bit.

- Make it more general (it's not just about stubbing). - Remove unused lines. - Improve doc output (`include_examples` does not create a nested group).


        Don't allow const stubbing/hiding from before(:all).


        Having a private `pretty_print` method causes problems.

When rspec-expectations tries to diff the object in a failure message, it blows up when the `pp` library tries to print it.


        Refactor space tracking so it uses a stack and allows nesting.


        Add RSpec::Mocks.with_temporary_scope.

Closes #240.


        Clean up expectation ordering.

- It was duplicated in Proxy. - Makes more sense to initialize it in Space init.


        Simplify spec.

rspec-mocks lacks the necessary sandboxing to safely define and run examples from within examples. rspec-core has and uses this but it's not exposed for use here. Instead, we can just trigger the teardown/setup that happens between examples. This fixes some rspec-mocks space leakage that was happening.


        Move mock_space_spec specs into space_spec.rb

Not sure how we wound up with two separate files, anyway.


        Remove unnecessary collection clearing.

Since we now use a new space instance per example, we don't need to clear its collections when resetting. Before this was necessary because we kept a space instance that we would keep using for the lifetime of the process. Constant mutators weren't being reset idempotently, so I had to tweak them a bit.


        Add changelog entry for test-double self-destruction.

[ci skip]

JonRowe · 2014-01-07T10:27:33Z

lib/rspec/mocks.rb

@@ -37,7 +25,8 @@ def self.verify
    # each example, even if an error was raised during the example.
    def self.teardown
      space.reset_all
-      self.space = ERROR_SPACE
+      @space_stack.pop


You could combine these two lines to @space = @space_stack.pop || @root_space no?

Nope. @space should be set to @space_stack.last after popping.

JonRowe · 2014-01-07T10:28:10Z

lib/rspec/mocks.rb

    # Performs per-test/example setup. This should be called before
    # an test or example begins.
    def self.setup
-      self.space = MOCK_SPACE
+      @space_stack << (@space = space.new_scope)


Why don't we just access @space_stack.last everywhere?

Or define space to be that?

I initially planned on doing that, but then was noticing that we access RSpec::Mocks.space all over the place from the rest of the rspec-mocks code (e.g. to call proxy_for on it), and while Array#last shouldn't be a slow method call, my instinct is that it can only be faster to have space already available for direct access. The cost of doing this is only the extra memory need for the @space ivar, but who cares about that?

Anyhow, putting it in the ivar also allows us to use attr_reader, which is apparently faster than any normal method definition could be:

rails/arel@ea1d050

JonRowe · 2014-01-07T10:29:52Z

lib/rspec/mocks/error_generator.rb

+          "another example and can no longer be used. rspec-mocks' doubles are " +
+          "designed to only last for one example, and you need to create a new " +
+          "one in each example you wish to use it for."
+      end


Would this be raised for a double created in a temporary scope then reused? Could that be confusing?

Yep. I tried to rephrase this to work for the temporary scope case but I couldn't come up with a phrasing I liked. On top of that, I'd consider using with_temporary_scope to be an "advanced" feature of rspec-mocks. I think a newcomer (who has no idea what "an rspec-mocks scope" is) is more likely to be confused by a message worded in those terms than someone using with_temporary_scope being confused by this message.

Anyhow, I'm open to alternate phrasings if you have an idea. I was also thinking it could be good to mention with_temporary_scope in the messages raised from RootSpace so people know that's available but I couldn't come up with a good way to include that in the message. Any ideas?

How about passing a variable to this method that defaults to example but when raised from with_temporary_scope sets it to context, then it'd be slightly less confusing in that scenario?

"#{intro} was originally created in one example but has leaked into " + "another context and can no longer be used. rspec-mocks' doubles are " + "designed to only last for one context, and you need to create a new " + "one in each context you wish to use it for."

I've tried to apply your suggestion, but applying it gets really complicated for all the different possibilities:

Created in a temporary scope, used in a later example.

Created in a temporary scope, used in a later temporary scope.

Created in an example, used in a later example.

Created in an example, used in a temporary scope after the example.

Doing this properly will require a bunch of extra state, for what is an edge case. I'm not convinced it's worth it...but maybe you want to take a stab at it after this is merged?

JonRowe · 2014-01-07T10:31:52Z

lib/rspec/mocks/proxy.rb

+        super
+      end
+
+      private


This should be dedented two spaces no?

JonRowe · 2014-01-07T10:32:13Z

Looking good so far but I left a few notes :)


        Indent `private` at same level as class.

This is our preferred convention.


        Merge pull request #519 from rspec/lifecycle-space-fixups

Lifecycle/space fixups

myronmarston added 10 commits Jan 3, 2014

Remove test we no longer need.

acd9a45

The logic that required this test was removed in cd81094.

Make test doubles self-destruct after the example completes.

f83810b

Test doubles are not designed to be used outside of the example they were created in.

Split spec into two.

358fbdb

The second part of this spec was added in 9357e4d. We are changing test doubles so that they self-destruct after being reset. Currently, `verify` also resets, so verifying a test double twice will no longer be allowed.

Update teardown spec.

0df4884

We're going to change how pure test doubles behave after teardown, so update this to focus on partial doubles (which will not be changed).

No need for ProxyForNil to have its own file.

3138bba

Centralize error classes in error_generator.rb.

Loading status checks…

b639f7e

Also, document some of them as public since users may want to rescue them, or specify a block will raise one of these errors (e.g. in an rspec-mocks extension gem).

Move error_space.rb into space.rb

83e56b0

There's no need for a separate file and there's going to be a bit of interaction between multiple spaces at various layers in a stack so having it in one file will make it easier to see how it relates.

myronmarston added 11 commits Jan 4, 2014

Refactor: store const mutators in mock space.

9da93fd

This unifies global storage of modified things in one place.

Re-work spec file a bit.

7c94a6f

- Make it more general (it's not just about stubbing). - Remove unused lines. - Improve doc output (`include_examples` does not create a nested group).

Don't allow const stubbing/hiding from before(:all).

d89e680

Having a private `pretty_print` method causes problems.

513bdb1

When rspec-expectations tries to diff the object in a failure message, it blows up when the `pp` library tries to print it.

Refactor space tracking so it uses a stack and allows nesting.

c28b379

Add RSpec::Mocks.with_temporary_scope.

Loading status checks…

3dcef6d

Closes #240.

Clean up expectation ordering.

98f065e

- It was duplicated in Proxy. - Makes more sense to initialize it in Space init.

Move mock_space_spec specs into space_spec.rb

90cf550

Not sure how we wound up with two separate files, anyway.

Add changelog entry for test-double self-destruction.

3ab7925

[ci skip]

This was referenced Jan 7, 2014

Remove extra mocks teardowns/sandboxing rspec/rspec-core#1242

Merged

Add deprecation to 2.99 for use of mocks in before(:all) #517

Closed

JonRowe reviewed Jan 7, 2014
View changes

lib/rspec/mocks/proxy.rb Outdated

super

end

private

This comment has been minimized.

Sign in to view

Copy link

JonRowe Jan 7, 2014
Member

This should be dedented two spaces no?

Indent `private` at same level as class.

Loading status checks…

c08a408

This is our preferred convention.

myronmarston mentioned this pull request Jan 9, 2014

Add deprecations for 519 to 2 99 #522

Merged

myronmarston added a commit that referenced this pull request Jan 9, 2014

Merge pull request #519 from rspec/lifecycle-space-fixups

Loading status checks…

8615dc2

Lifecycle/space fixups

myronmarston merged commit 8615dc2 into master Jan 9, 2014
1 check passed

1 check passed

default The Travis CI build passed
Details

myronmarston deleted the lifecycle-space-fixups branch Jan 9, 2014

myronmarston mentioned this pull request Jan 20, 2014

Use of mocks in before(:all) #528

Closed

myronmarston mentioned this pull request Feb 25, 2014

Don't double reset #592

Merged

rspec / rspec-mocks

Lifecycle/space fixups #519

Lifecycle/space fixups #519

myronmarston commented Jan 4, 2014

penelopezone commented Jan 4, 2014

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

JonRowe commented Jan 7, 2014

+                super
+              end
+              private

rspec / rspec-mocks

Sponsor rspec/rspec-mocks

Join GitHub today

Lifecycle/space fixups #519

Lifecycle/space fixups #519

Conversation

myronmarston commented Jan 4, 2014

penelopezone commented Jan 4, 2014

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

JonRowe commented Jan 7, 2014