From 8e8a3205a04af46323ca73a9ebfa140429038aec Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Thu, 17 Sep 2020 01:00:46 +0900
Subject: [PATCH] Fix an error for `Lint/UselessTimes`

This PR fixes the following error for `Lint/UselessTimes`
when using empty block argument.

```console
% cat example.rb
def foo
  1.times do
  end
end

% rubocop --only Lint/UselessTimes -d
(snip)

Inspecting 1 file
Scanning /Users/koic/src/github.com/koic/rubocop-issues/bar/example.rb
An error occurred while Lint/UselessTimes cop was inspecting
/Users/koic/src/github.com/koic/rubocop-issues/bar/example.rb:2:2.
undefined method `source' for nil:NilClass
/Users/koic/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/
lib/rubocop/cop/lint/useless_times.rb:76:in `autocorrect_block'
/Users/koic/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/
lib/rubocop/cop/lint/useless_times.rb:57:in `block in on_send'
/Users/koic/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/
lib/rubocop/cop/base.rb:333:in `correct'
/Users/koic/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/
lib/rubocop/cop/base.rb:126:in `add_offense'
/Users/koic/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/
lib/rubocop/cop/lint/useless_times.rb:49:in `on_send'
```
---
 CHANGELOG.md                                |  1 +
 lib/rubocop/cop/lint/useless_times.rb       |  6 +++++-
 spec/rubocop/cop/lint/useless_times_spec.rb | 15 +++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce1ae64b04b..1a72ed8fc2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 * [#8726](https://github.com/rubocop-hq/rubocop/issues/8726): Fix a false positive for `Naming/VariableNumber` when naming multibyte character variable name. ([@koic][])
 * [#8730](https://github.com/rubocop-hq/rubocop/issues/8730): Fix an error for `Lint/UselessTimes` when there is a blank line in the method definition. ([@koic][])
 * [#8740](https://github.com/rubocop-hq/rubocop/issues/8740): Fix a false positive for `Style/HashAsLastArrayItem` when the hash is in an implicit array. ([@dvandersluis][])
+* [#8739](https://github.com/rubocop-hq/rubocop/issues/8739): Fix an error for `Lint/UselessTimes` when using empty block argument. ([@koic][])
 
 ### Changes
 
diff --git a/lib/rubocop/cop/lint/useless_times.rb b/lib/rubocop/cop/lint/useless_times.rb
index 32c4703c172..9c7ef6e609e 100644
--- a/lib/rubocop/cop/lint/useless_times.rb
+++ b/lib/rubocop/cop/lint/useless_times.rb
@@ -49,7 +49,7 @@ def on_send(node)
           add_offense(node, message: format(MSG, count: count)) do |corrector|
             next unless own_line?(node)
 
-            if count < 1
+            if never_process?(count, node)
               remove_node(corrector, node)
             elsif !proc_name.empty?
               autocorrect_block_pass(corrector, node, proc_name)
@@ -61,6 +61,10 @@ def on_send(node)
 
         private
 
+        def never_process?(count, node)
+          count < 1 || node.block_type? && node.body.nil?
+        end
+
         def remove_node(corrector, node)
           corrector.remove(range_by_whole_lines(node.loc.expression, include_final_newline: true))
         end
diff --git a/spec/rubocop/cop/lint/useless_times_spec.rb b/spec/rubocop/cop/lint/useless_times_spec.rb
index b609dcba3eb..1e1574d97b4 100644
--- a/spec/rubocop/cop/lint/useless_times_spec.rb
+++ b/spec/rubocop/cop/lint/useless_times_spec.rb
@@ -61,6 +61,21 @@
     RUBY
   end
 
+  it 'registers an offense and corrects when 1.times with empty block argument' do
+    expect_offense(<<~RUBY)
+      def foo
+        1.times do
+        ^^^^^^^^^^ Useless call to `1.times` detected.
+        end
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      def foo
+      end
+    RUBY
+  end
+
   it 'registers an offense and corrects when there is a blank line in the method definition' do
     expect_offense(<<~RUBY)
       def foo