Merge pull request #1140 from koic/fix_false_positives_for_redundant_presence_validation_on_belongs_to

[Fix #1105] Fix false positives for `Rails/RedundantPresenceValidationOnBelongsTo`

Author: koic

changelog/fix_false_positives_for_redundant_presence_validation_on_belongs_to.md

@@ -0,0 +1 @@
+* [#1105](https://github.com/rubocop/rubocop-rails/issues/1105): Fix false positives for `Rails/RedundantPresenceValidationOnBelongsTo` when using `validates` with `:if` or `:unless` options. ([@koic][])

lib/rubocop/cop/rails/redundant_presence_validation_on_belongs_to.rb

@@ -53,6 +53,12 @@ class RedundantPresenceValidationOnBelongsTo < Base
         #   @example source that matches - by a foreign key
         #     validates :user_id, presence: true
         #
+        #   @example source that DOES NOT match - if condition
+        #     validates :user_id, presence: true, if: condition
+        #
+        #   @example source that DOES NOT match - unless condition
+        #     validates :user_id, presence: true, unless: condition
+        #
         #   @example source that DOES NOT match - strict validation
         #     validates :user_id, presence: true, strict: true
         #
@@ -65,6 +71,7 @@ class RedundantPresenceValidationOnBelongsTo < Base
             $[
               (hash <$(pair (sym :presence) true) ...>)         # presence: true
               !(hash <$(pair (sym :strict) {true const}) ...>)  # strict: true
+              !(hash <$(pair (sym {:if :unless}) _) ...>)       # if: some_condition or unless: some_condition
             ]
           )
         PATTERN

spec/rubocop/cop/rails/redundant_presence_validation_on_belongs_to_spec.rb

@@ -271,6 +271,20 @@ class Profile
       RUBY
     end
 
+    it 'does not register an offense with `if` option' do
+      expect_no_offenses(<<~RUBY)
+        belongs_to :user
+        validates :user, presence: true, if: -> { condition }
+      RUBY
+    end
+
+    it 'does not register an offense with `unless` option' do
+      expect_no_offenses(<<~RUBY)
+        belongs_to :user
+        validates :user, presence: true, unless: -> { condition }
+      RUBY
+    end
+
     it 'does not register an offense with strict validation' do
       expect_no_offenses(<<~RUBY)
         belongs_to :user