Require VoidExpect to operate inside an example block

[corsonknowles]

This PR completes branch coverage for VoidExpect.

This PR copies the inside_example? method and re-uses it here to get more coherent behavior from the VoidExpect cop.

Note that if we were thinking of copying inside_example? a 3rd time, I'd suggest factoring it out into a utility (Sandi Metz' rule of 3).

Note that I remove the return true unless parent guard clause, because we expect the inside_example? guard clause to fully cover that condition.

Split from:

• Complete branch coverage for ContextWording #1972

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Before submitting the PR make sure the following are checked:

• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Updated documentation.
• Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
• The build (bundle exec rake) passes (be sure to run this locally, since it may produce updated documentation that you will need to commit).

If you have created a new cop:

• Added the new cop to config/default.yml.
• The cop is configured as Enabled: pending in config/default.yml.
• The cop is configured as Enabled: true in .rubocop.yml.
• The cop documents examples of good and bad code.
• The tests assert both that bad code is reported and that good code is not reported.
• Set VersionAdded: "<<next>>" in default/config.yml.

If you have modified an existing cop's configuration options:

• Set VersionChanged: "<<next>>" in config/default.yml.

[pirj]

Thanks!

@rubocop/rubocop-rspec I’d merge this right away, as this allows to remove some nonsensical examples for this cop in the coverage tightening PR.

[corsonknowles]

@pirj Can you review 1 more time please?

I think I solved this, but it entails removing this guard clause
return true unless parent
in favor of what I believe is the much more restrictive one:
return unless inside_example?(node)

At this point, I can probably drop all VoidExpect changes from the other PR, so it's just amending that 1 other spec file.

[pirj]

I’d just removed all this except the first one.

[corsonknowles]

We need the block version below to cover the new guard clause in on_block

I'll delete the rest and get this merged in.

[pirj]

A huge 👍 from me, thank you!

[corsonknowles]

@pirj Feel free to merge at will
(or reapprove and I will merge? however this works)

[pirj]

We usually get consensus on things that might be user-facing, so I’ll pass on merging to the next reviewer.

May I kindly ask to add a short changelog note that the cop was fixed to only inspect code inside examples?

[corsonknowles]

Thanks! CHANGELOG entry added.

[corsonknowles]

@bquorning Would you be up for doing the 2nd review on this one?

[ydah]

Looks good!

[bquorning]

Yep, looks good 👍🏼