rubocop · bbatsov · Sep 4, 2024 · Sep 3, 2024
diff --git a/changelog/fix_an_error_for_style_if_with_semicolon.md b/changelog/fix_an_error_for_style_if_with_semicolon.md
@@ -0,0 +1 @@
+* [#13191](https://github.com/rubocop/rubocop/pull/13191): Fix an error for `Style/IfWithSemicolon` when using nested single-line if/;/end in block of if/else branches. ([@koic][])
diff --git a/lib/rubocop/cop/style/if_with_semicolon.rb b/lib/rubocop/cop/style/if_with_semicolon.rb
@@ -36,26 +36,33 @@ def on_normal_if_unless(node)
 
         private
 
+        # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
         def message(node)
           template = if node.if_branch&.begin_type?
                        MSG_NEWLINE
-                     elsif node.else_branch&.if_type? || node.else_branch&.begin_type?
+                     elsif node.else_branch&.if_type? || node.else_branch&.begin_type? ||
+                           use_block_in_branches?(node)
                        MSG_IF_ELSE
                      else
                        MSG_TERNARY
                      end
 
           format(template, expr: node.condition.source)
         end
+        # rubocop:enable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
 
         def autocorrect(corrector, node)
-          if node.if_branch&.begin_type? || node.else_branch&.begin_type?
+          if node.branches.compact.any?(&:begin_type?) || use_block_in_branches?(node)
             corrector.replace(node.loc.begin, "\n")
           else
             corrector.replace(node, replacement(node))
           end
         end
 
+        def use_block_in_branches?(node)
+          node.branches.compact.any? { |branch| branch.block_type? || branch.numblock_type? }
+        end
+
         def replacement(node)
           return correct_elsif(node) if node.else_branch&.if_type?
 

diff --git a/spec/rubocop/cop/style/if_with_semicolon_spec.rb b/spec/rubocop/cop/style/if_with_semicolon_spec.rb
@@ -203,5 +203,57 @@ class Hash
         end
       RUBY
     end
+
+    it 'registers an offense and corrects when using nested single-line if/;/end in block of if body' do
+      expect_offense(<<~RUBY)
+        if foo?; bar { if qux?; quux else end } end
+                       ^^^^^^^^^^^^^^^^^^^^^^ Do not use `if qux?;` - use a ternary operator instead.
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Do not use `if foo?;` - use `if/else` instead.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        if foo?
+         bar { qux? ? quux : nil } end
+      RUBY
+    end
+
+    it 'registers an offense and corrects when using nested single-line if/;/end in the block of else body' do
+      expect_offense(<<~RUBY)
+        if foo?; bar else baz { if qux?; quux else end } end
+                                ^^^^^^^^^^^^^^^^^^^^^^ Do not use `if qux?;` - use a ternary operator instead.
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Do not use `if foo?;` - use `if/else` instead.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        if foo?
+         bar else baz { qux? ? quux : nil } end
+      RUBY
+    end
+
+    it 'registers an offense and corrects when using nested single-line if/;/end in numblock of if body' do
+      expect_offense(<<~RUBY)
+        if foo?; bar { if _1; quux else end } end
+                       ^^^^^^^^^^^^^^^^^^^^ Do not use `if _1;` - use a ternary operator instead.
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Do not use `if foo?;` - use `if/else` instead.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        if foo?
+         bar { _1 ? quux : nil } end
+      RUBY
+    end
+
+    it 'registers an offense and corrects when using nested single-line if/;/end in the numblock of else body' do
+      expect_offense(<<~RUBY)
+        if foo?; bar else baz { if _1; quux else end } end
+                                ^^^^^^^^^^^^^^^^^^^^ Do not use `if _1;` - use a ternary operator instead.
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Do not use `if foo?;` - use `if/else` instead.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        if foo?
+         bar else baz { _1 ? quux : nil } end
+      RUBY
+    end
   end
 end
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		* [#13191](https://github.com/rubocop/rubocop/pull/13191): Fix an error for `Style/IfWithSemicolon` when using nested single-line if/;/end in block of if/else branches. ([@koic][])