Merge pull request #629 from koic/fix_a_false_positive_for_rails_compact_blank

[Fix #628] Fix a false positive for `Rails/CompactBlank`

Author: koic

lib/rubocop/cop/rails/compact_blank.rb

@@ -10,25 +10,21 @@ module Rails
       #   blank check of block arguments to the receiver object.
       #
       #   For example, `[[1, 2], [3, nil]].reject { |first, second| second.blank? }` and
-      #   `[[1, 2], [3, nil]].compact_blank` are not compatible. The same is true for `empty?`.
+      #   `[[1, 2], [3, nil]].compact_blank` are not compatible. The same is true for `blank?`.
       #   This will work fine when the receiver is a hash object.
       #
       # @example
       #
       #   # bad
       #   collection.reject(&:blank?)
-      #   collection.reject(&:empty?)
       #   collection.reject { |_k, v| v.blank? }
-      #   collection.reject { |_k, v| v.empty? }
       #
       #   # good
       #   collection.compact_blank
       #
       #   # bad
       #   collection.reject!(&:blank?)
-      #   collection.reject!(&:empty?)
       #   collection.reject! { |_k, v| v.blank? }
-      #   collection.reject! { |_k, v| v.empty? }
       #
       #   # good
       #   collection.compact_blank!
@@ -48,13 +44,13 @@ class CompactBlank < Base
             (send _ {:reject :reject!})
             $(args ...)
             (send
-              $(lvar _) {:blank? :empty?}))
+              $(lvar _) :blank?))
         PATTERN
 
         def_node_matcher :reject_with_block_pass?, <<~PATTERN
           (send _ {:reject :reject!}
             (block_pass
-              (sym {:blank? :empty?})))
+              (sym :blank?)))
         PATTERN
 
         def on_send(node)

spec/rubocop/cop/rails/compact_blank_spec.rb

@@ -13,17 +13,6 @@
       RUBY
     end
 
-    it 'registers and corrects an offense when using `reject { |e| e.empty? }`' do
-      expect_offense(<<~RUBY)
-        collection.reject { |e| e.empty? }
-                   ^^^^^^^^^^^^^^^^^^^^^^^ Use `compact_blank` instead.
-      RUBY
-
-      expect_correction(<<~RUBY)
-        collection.compact_blank
-      RUBY
-    end
-
     it 'registers and corrects an offense when using `reject(&:blank?)`' do
       expect_offense(<<~RUBY)
         collection.reject(&:blank?)
@@ -35,17 +24,6 @@
       RUBY
     end
 
-    it 'registers and corrects an offense when using `reject(&:empty?)`' do
-      expect_offense(<<~RUBY)
-        collection.reject(&:empty?)
-                   ^^^^^^^^^^^^^^^^ Use `compact_blank` instead.
-      RUBY
-
-      expect_correction(<<~RUBY)
-        collection.compact_blank
-      RUBY
-    end
-
     it 'registers and corrects an offense when using `reject! { |e| e.blank? }`' do
       expect_offense(<<~RUBY)
         collection.reject! { |e| e.blank? }
@@ -57,17 +35,6 @@
       RUBY
     end
 
-    it 'registers and corrects an offense when using `reject! { |e| e.empty? }`' do
-      expect_offense(<<~RUBY)
-        collection.reject! { |e| e.empty? }
-                   ^^^^^^^^^^^^^^^^^^^^^^^^ Use `compact_blank!` instead.
-      RUBY
-
-      expect_correction(<<~RUBY)
-        collection.compact_blank!
-      RUBY
-    end
-
     it 'registers and corrects an offense when using `reject!(&:blank?)`' do
       expect_offense(<<~RUBY)
         collection.reject!(&:blank?)
@@ -79,28 +46,6 @@
       RUBY
     end
 
-    it 'registers and corrects an offense when using `reject!(&:empty?)`' do
-      expect_offense(<<~RUBY)
-        collection.reject!(&:empty?)
-                   ^^^^^^^^^^^^^^^^^ Use `compact_blank!` instead.
-      RUBY
-
-      expect_correction(<<~RUBY)
-        collection.compact_blank!
-      RUBY
-    end
-
-    it 'registers and corrects an offense when using `reject { |k, v| v.empty? }`' do
-      expect_offense(<<~RUBY)
-        collection.reject { |k, v| v.empty? }
-                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `compact_blank` instead.
-      RUBY
-
-      expect_correction(<<~RUBY)
-        collection.compact_blank
-      RUBY
-    end
-
     it 'does not register an offense when using `compact_blank`' do
       expect_no_offenses(<<~RUBY)
         collection.compact_blank
@@ -113,9 +58,9 @@
       RUBY
     end
 
-    it 'does not register an offense when using `reject { |k, v| k.empty? }`' do
+    it 'does not register an offense when using `reject { |k, v| k.blank? }`' do
       expect_no_offenses(<<~RUBY)
-        collection.reject { |k, v| k.empty? }
+        collection.reject { |k, v| k.blank? }
       RUBY
     end
 
@@ -126,6 +71,12 @@ def foo(arg)
         end
       RUBY
     end
+
+    it 'does not register an offense when using `reject { |e| e.empty? }`' do
+      expect_no_offenses(<<~RUBY)
+        collection.reject { |e| e.empty? }
+      RUBY
+    end
   end
 
   context 'Rails <= 6.0', :rails60 do