[Fix rubocop#3382] Fix EmptyElse with multiple elsifs

An `if-elsif-else` expression containing multiple elsifs does not crash
when auto-correcting.

CHANGELOG.md

@@ -22,6 +22,7 @@
 * [#3411](https://github.com/bbatsov/rubocop/issues/3411): Avoid auto-correction crash for single `when` in `Performance/CaseWhenSplat`. ([@jonas054][])
 * [#3286](https://github.com/bbatsov/rubocop/issues/3286): Allow `self.a, self.b = b, a` in `Style/ParallelAssignment`. ([@jonas054][])
 * [#3419](https://github.com/bbatsov/rubocop/issues/3419): Report offense for `unless x.nil?` in `Style/NonNilCheck` if `IncludeSemanticChanges` is `true`. ([@jonas054][])
+* [#3382](https://github.com/bbatsov/rubocop/issues/3382): Avoid auto-correction crash for multiple elsifs in `Style/EmptyElse`. ([@lumeet][])
 
 ### Changes
 

lib/rubocop/cop/style/empty_else.rb

@@ -110,16 +110,18 @@ def autocorrect(node)
           return false if autocorrect_forbidden?(node.type.to_s)
 
           lambda do |corrector|
-            end_pos = if node.loc.end
-                        node.loc.end.begin_pos
-                      else
-                        node.parent.loc.end.begin_pos
-                      end
+            end_pos = base_if_node(node).loc.end.begin_pos
 
             corrector.remove(range_between(node.loc.else.begin_pos, end_pos))
           end
         end
 
+        def base_if_node(node)
+          parent_node = node
+          parent_node = parent_node.parent until parent_node.loc.end
+          parent_node
+        end
+
         def autocorrect_forbidden?(type)
           [type, 'both'].include? missing_else_style
         end

spec/rubocop/cop/style/empty_else_spec.rb

@@ -235,11 +235,21 @@
 
       context 'with an else-clause containing only the literal nil ' \
               'using semicolons' do
-        let(:source) { 'if a; foo elsif b; bar else nil end' }
-        let(:corrected_source) { 'if a; foo elsif b; bar end' }
+        context 'with one elsif' do
+          let(:source) { 'if a; foo elsif b; bar else nil end' }
+          let(:corrected_source) { 'if a; foo elsif b; bar end' }
 
-        it_behaves_like 'offense registration'
-        it_behaves_like 'auto-correct', 'if'
+          it_behaves_like 'offense registration'
+          it_behaves_like 'auto-correct', 'if'
+        end
+
+        context 'with multiple elsifs' do
+          let(:source) { 'if a; foo elsif b; bar; elsif c; bar else nil end' }
+          let(:corrected_source) { 'if a; foo elsif b; bar; elsif c; bar end' }
+
+          it_behaves_like 'offense registration'
+          it_behaves_like 'auto-correct', 'if'
+        end
       end
 
       context 'with an else-clause with side-effects' do
@@ -366,11 +376,21 @@
       end
 
       context 'with an else-clause containing only the literal nil' do
-        let(:source) { 'if a; foo elsif b; bar else nil end' }
-        let(:corrected_source) { 'if a; foo elsif b; bar end' }
+        context 'with one elsif' do
+          let(:source) { 'if a; foo elsif b; bar else nil end' }
+          let(:corrected_source) { 'if a; foo elsif b; bar end' }
 
-        it_behaves_like 'offense registration'
-        it_behaves_like 'auto-correct', 'if'
+          it_behaves_like 'offense registration'
+          it_behaves_like 'auto-correct', 'if'
+        end
+
+        context 'with multiple elsifs' do
+          let(:source) { 'if a; foo elsif b; bar; elsif c; bar else nil end' }
+          let(:corrected_source) { 'if a; foo elsif b; bar; elsif c; bar end' }
+
+          it_behaves_like 'offense registration'
+          it_behaves_like 'auto-correct', 'if'
+        end
       end
 
       context 'with an else-clause with side-effects' do