[Fix #8008] Fix an error for Lint/SuppressedException

Fixes #8008.

This PR fixes an error for `Lint/SuppressedException`
when empty rescue block in `def`.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Bug fixes
+
+* [#8008](https://github.com/rubocop-hq/rubocop/issues/8008): Fix an error for `Lint/SuppressedException` when empty rescue block in `def`. ([@koic][])
+
 ## 0.84.0 (2020-05-21)
 
 ### New features

lib/rubocop/cop/lint/suppressed_exception.rb

@@ -82,6 +82,8 @@ def comment_between_rescue_and_end?(node)
             end_line = ancestor.loc.end.line
             break
           end
+          return false unless end_line
+
           processed_source[node.first_line...end_line].any? { |line| comment_line?(line) }
         end
       end

spec/rubocop/cop/lint/suppressed_exception_spec.rb

@@ -41,6 +41,16 @@
       RUBY
     end
 
+    it 'registers an offense for empty rescue block in `def`' do
+      expect_offense(<<~RUBY)
+        def foo
+          do_something
+        rescue
+        ^^^^^^ Do not suppress exceptions.
+        end
+      RUBY
+    end
+
     it 'registers an offense for empty rescue on single line with a comment after it' do
       expect_offense(<<~RUBY)
         RSpec.describe Dummy do