Add new RSpec/Rails/NegationBeValid cop

Fix: rubocop/rubocop-rspec#1660

.simplecov

@@ -2,7 +2,7 @@
 
 SimpleCov.start do
  enable_coverage :branch
- minimum_coverage line: 99.60, branch: 94.84
+ minimum_coverage line: 99.60, branch: 94.77
  add_filter '/spec/'
  add_filter '/vendor/bundle/'
 end

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Master (Unreleased)
 
+- Add new `RSpec/Rails/NegationBeValid` cop. ([@ydah])
 - Fix a false negative for `RSpec/ExcessiveDocstringSpacing` when finds description with em space. ([@ydah])
 - Fix a false positive for `RSpec/EmptyExampleGroup` when example group with examples defined in `if` branch inside iterator. ([@ydah])
 - Update the message output of `RSpec/ExpectActual` to include the word 'value'. ([@corydiamand])

config/default.yml

@@ -1104,6 +1104,16 @@ RSpec/Rails/MinitestAssertions:
  VersionAdded: '2.17'
  Reference: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/MinitestAssertions
 
+RSpec/Rails/NegationBeValid:
+ Description: Enforces use of `be_invalid` or `not_to` for negated be_valid.
+ EnforcedStyle: not_to
+ SupportedStyles:
+ - not_to
+ - be_invalid
+ Enabled: pending
+ VersionAdded: "<<next>>"
+ Reference: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/NegationBeValid
+
 RSpec/Rails/TravelAround:
  Description: Prefer to travel in `before` rather than `around`.
  Enabled: pending

docs/modules/ROOT/pages/cops.adoc

@@ -128,6 +128,7 @@
 * xref:cops_rspec_rails.adoc#rspecrails/httpstatus[RSpec/Rails/HttpStatus]
 * xref:cops_rspec_rails.adoc#rspecrails/inferredspectype[RSpec/Rails/InferredSpecType]
 * xref:cops_rspec_rails.adoc#rspecrails/minitestassertions[RSpec/Rails/MinitestAssertions]
+* xref:cops_rspec_rails.adoc#rspecrails/negationbevalid[RSpec/Rails/NegationBeValid]
 * xref:cops_rspec_rails.adoc#rspecrails/travelaround[RSpec/Rails/TravelAround]
 
 // END_COP_LIST

docs/modules/ROOT/pages/cops_rspecrails.adoc

@@ -261,6 +261,58 @@ expect(b).not_to eq(a)
 
 * https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/MinitestAssertions
 
+== RSpec/Rails/NegationBeValid
+
+|===
+| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed
+
+| Pending
+| Yes
+| Yes
+| <<next>>
+| -
+|===
+
+Enforces use of `be_invalid` or `not_to` for negated be_valid.
+
+=== Examples
+
+==== EnforcedStyle: not_to (default)
+
+[source,ruby]
+----
+# bad
+expect(foo).to be_invalid
+
+# good
+expect(foo).not_to be_valid
+----
+
+==== EnforcedStyle: be_invalid
+
+[source,ruby]
+----
+# bad
+expect(foo).not_to be_valid
+
+# good
+expect(foo).to be_invalid
+----
+
+=== Configurable attributes
+
+|===
+| Name | Default value | Configurable values
+
+| EnforcedStyle
+| `not_to`
+| `not_to`, `be_invalid`
+|===
+
+=== References
+
+* https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/NegationBeValid
+
 == RSpec/Rails/TravelAround
 
 |===

spec/rubocop/cop/rspec_rails/negation_be_valid_spec.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::RSpec::Rails::NegationBeValid do
+ let(:cop_config) { { 'EnforcedStyle' => enforced_style } }
+
+ context 'with EnforcedStyle `not_to`' do
+ let(:enforced_style) { 'not_to' }
+
+ it 'registers an offense when using ' \
+ '`expect(...).to be_invalid`' do
+ expect_offense(<<~RUBY)
+ expect(foo).to be_invalid
+ ^^^^^^^^^^^^^ Use `expect(...).not_to be_valid`.
+ RUBY
+ end
+
+ it 'does not register an offense when using ' \
+ '`expect(...).not_to be_valid`' do
+ expect_no_offenses(<<~RUBY)
+ expect(foo).not_to be_valid
+ RUBY
+ end
+
+ it 'does not register an offense when using ' \
+ '`expect(...).to be_valid`' do
+ expect_no_offenses(<<~RUBY)
+ expect(foo).to be_valid
+ RUBY
+ end
+ end
+
+ context 'with EnforcedStyle `be_invalid`' do
+ let(:enforced_style) { 'be_invalid' }
+
+ it 'registers an offense when using ' \
+ '`expect(...).not_to be_valid`' do
+ expect_offense(<<~RUBY)
+ expect(foo).not_to be_valid
+ ^^^^^^^^^^^^^^^ Use `expect(...).to be_invalid`.
+ RUBY
+ end
+
+ it 'does not register an offense when using ' \
+ '`expect(...).to be_invalid`' do
+ expect_no_offenses(<<~RUBY)
+ expect(foo).to be_invalid
+ RUBY
+ end
+
+ it 'does not register an offense when using ' \
+ '`expect(...).to be_valid`' do
+ expect_no_offenses(<<~RUBY)
+ expect(foo).to be_valid
+ RUBY
+ end
+ end
+end