Fix for new_cop rake task

[francoisa]

Replace this text with a summary of the changes in your PR.
The more detailed you are, the better.

---

Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Run bundle exec rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[francoisa]

I've never submitted a PR to a github repo before and I am not an experienced ruby developer, but the new_cop rake task would fail with:

rake aborted!
TypeError: no implicit conversion from nil to integer
.../rubocop-hq/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `insert'
.../rubocop-hq/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `inject'
.../rubocop-hq/rubocop/lib/rubocop/cop/generator.rb:136:in `inject_config'
tasks/new_cop.rake:20:in `block in <top (required)>'
.../2.5.1/bin/bundle:23:in `load'
.../2.5.1/bin/bundle:23:in `<main>'
Tasks: TOP => new_cop
(See full trace by running task with --trace)

until I put this fix in.

[wata727]

@francoisa Thanks for your contribution. I tried the new_cop rake task, but I cannot reproduce the above error...

% bundle exec rake new_cop\[Rails/Test\]
[create] lib/rubocop/cop/rails/test.rb
[create] spec/rubocop/cop/rails/test_spec.rb
[modify] lib/rubocop.rb - `require_relative 'rubocop/cop/rails/test'` was injected.
[modify] A configuration for the cop is added into config/default.yml.
         If you want to disable the cop by default, set `Enabled` option to false.
Do 3 steps:
  1. Add an entry to the "New features" section in CHANGELOG.md,
     e.g. "Add new `Rails/Test` cop. ([@your_id][])"
  2. Modify the description of Rails/Test in config/default.yml
  3. Implement your new cop in the generated file!

FWIW, if config/default.yml is empty, it seems that a similar error occurs.

% :> config/default.yml
% bundle exec rake new_cop\[Rails/Test\]
[create] lib/rubocop/cop/rails/test.rb
[create] spec/rubocop/cop/rails/test_spec.rb
[modify] lib/rubocop.rb - `require_relative 'rubocop/cop/rails/test'` was injected.
rake aborted!
TypeError: no implicit conversion from nil to integer
/Users/watanabekazuma/workspace/ruby/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `insert'
/Users/watanabekazuma/workspace/ruby/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `inject'
/Users/watanabekazuma/workspace/ruby/rubocop/lib/rubocop/cop/generator.rb:136:in `inject_config'
tasks/new_cop.rake:20:in `block in <top (required)>'
/Users/watanabekazuma/.rbenv/versions/2.4.1/bin/bundle:22:in `load'
/Users/watanabekazuma/.rbenv/versions/2.4.1/bin/bundle:22:in `<main>'
Tasks: TOP => new_cop
(See full trace by running task with --trace)

Please check again whether the problem is reproduced. Also, make sure that config/default.yml has not been changed.

[pocke]

@francoisa Can you show me the full command when it's errored? e.g. bundle exec rake 'new_cop[Foo/Bar]'

I got the same error when the added cop's department does not exist, and the department is the last of dictionary order.
For example:

$ bundle exec rake new_cop[Zzz/Aaa]
/home/pocke/.rbenv/versions/trunk/lib/ruby/gems/2.7.0/gems/parser-2.5.3.0/lib/parser/lexer.rb:10836: warning: assigned but unused variable - testEof
rake aborted!
TypeError: no implicit conversion from nil to integer
/home/pocke/ghq/github.com/rubocop-hq/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `insert'
/home/pocke/ghq/github.com/rubocop-hq/rubocop/lib/rubocop/cop/generator/configuration_injector.rb:26:in `inject'
/home/pocke/ghq/github.com/rubocop-hq/rubocop/lib/rubocop/cop/generator.rb:136:in `inject_config'
tasks/new_cop.rake:20:in `block in <top (required)>'
/home/pocke/.rbenv/versions/trunk/bin/bundle:23:in `load'
/home/pocke/.rbenv/versions/trunk/bin/bundle:23:in `<main>'
Tasks: TOP => new_cop
(See full trace by running task with --trace)
[create] lib/rubocop/cop/zzz/aaa.rb
[create] spec/rubocop/cop/zzz/aaa_spec.rb

[francoisa]

Sorry for taking so long to reply. The command I used was:

bundle exec rake new_cop[blaw/settings]

I am using ruby 2.5.3. The steps I took were:

1. Forked rubocop
2. Cloned rubocop (on a macos mojave machine)
3. Changed to the rubocop directory
   4, Ran the command above

[pocke]

Thank you.
It is the same problem with my explain. Because there are lowercase letters after uppercase letters in ASCII code.

I think this pull request has only a few problem.
It injects the new cop's configuration to bottom of the file, but it actually inject the config before the last cop's config with this patch.

For example:

$ bundle exec  rake 'new_cop[Zzz/Aaa]'
$ git diff
diff --git a/config/default.yml b/config/default.yml
index da0926a63..e0be7a1a3 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -4304,6 +4304,11 @@ Style/YodaCondition:
   VersionAdded: '0.49'
   VersionChanged: '0.50'
 
+Zzz/Aaa:
+  Description: 'TODO: Write a description of the cop.'
+  Enabled: true
+  VersionAdded: '0.63'
+
 Style/ZeroLengthPredicate:
   Description: 'Use #empty? when testing for objects of length 0.'
   Enabled: true

I guess find_target_line can return configuration_entries.size -1 instead of last_line variable to avoid this problem.

[francoisa]

Code refactored.

[Drenmi]

@pocke Are you okay with the changes? I'm ready to merge this if you think it's okay. 🙂

[pocke]

Thank you!

[pocke]

The build on AppVeyor is faled, but I think we can ignore the failure because it only a network problem.

fatal: unable to access 'https://github.com/rubocop-hq/rubocop.git/': Could not resolve host: github.com
https://ci.appveyor.com/project/bbatsov/rubocop/builds/21785086/job/k076e1p4ssm93o7s

@Drenmi I think it's ready to merge. Thanks!

[Drenmi]

Thank you, @francoisa! 🙇