Return global offenses for Style/Copyright when the file is empty.

Very similar to #12802

This adds a check that the returned offenses have a location that formatters can display.
While the standard formatter catched the `IndexError`, barely any others did.

Since it is not possible to autocorrect global offenses, just don't do that. Adding autocorrect support would be a bunch more work.

changelog/fix_return_global_offenses_for_style_copyright.md

@@ -0,0 +1 @@
+* [#12804](https://github.com/rubocop/rubocop/pull/12804): Return global offenses for `Style/Copyright` when the file is empty. ([@earlopain][])

lib/rubocop/cop/style/copyright.rb

@@ -28,18 +28,27 @@ class Copyright < Base
         def on_new_investigation
           return if notice.empty? || notice_found?(processed_source)
 
-          add_offense(offense_range, message: format(MSG, notice: notice)) do |corrector|
-            verify_autocorrect_notice!
-
-            token = insert_notice_before(processed_source)
-            range = token.nil? ? range_between(0, 0) : token.pos
-
-            corrector.insert_before(range, "#{autocorrect_notice}\n")
+          verify_autocorrect_notice!
+          message = format(MSG, notice: notice)
+          if processed_source.blank?
+            add_global_offense(message)
+          else
+            offense_range = source_range(processed_source.buffer, 1, 0)
+            add_offense(offense_range, message: message) do |corrector|
+              autocorrect(corrector)
+            end
           end
         end
 
         private
 
+        def autocorrect(corrector)
+          token = insert_notice_before(processed_source)
+          range = token.nil? ? range_between(0, 0) : token.pos
+
+          corrector.insert_before(range, "#{autocorrect_notice}\n")
+        end
+
         def notice
           cop_config['Notice']
         end
@@ -48,10 +57,6 @@ def autocorrect_notice
           cop_config['AutocorrectNotice']
         end
 
-        def offense_range
-          source_range(processed_source.buffer, 1, 0)
-        end
-
         def verify_autocorrect_notice!
           raise Warning, AUTOCORRECT_EMPTY_WARNING if autocorrect_notice.empty?
 

lib/rubocop/formatter/clang_style_formatter.rb

@@ -24,14 +24,10 @@ def report_offense(file, offense)
           message: message(offense)
         )
 
-        begin
-          return unless valid_line?(offense)
+        return unless valid_line?(offense)
 
-          report_line(offense.location)
-          report_highlighted_area(offense.highlighted_area)
-        rescue IndexError
-          # range is not on a valid line; perhaps the source file is empty
-        end
+        report_line(offense.location)
+        report_highlighted_area(offense.highlighted_area)
       end
 
       def valid_line?(offense)

lib/rubocop/formatter/tap_formatter.rb

@@ -53,14 +53,10 @@ def report_offense(file, offense)
           message: message(offense)
         )
 
-        begin
-          return unless valid_line?(offense)
+        return unless valid_line?(offense)
 
-          report_line(offense.location)
-          report_highlighted_area(offense.highlighted_area)
-        rescue IndexError
-          # range is not on a valid line; perhaps the source file is empty
-        end
+        report_line(offense.location)
+        report_highlighted_area(offense.highlighted_area)
       end
 
       def annotate_message(msg)

lib/rubocop/rspec/expect_offense.rb

@@ -111,6 +111,7 @@ def format_offense(source, **replacements)
         source
       end
 
+      # rubocop:disable Metrics/AbcSize
       def expect_offense(source, file = nil, severity: nil, chomp: false, **replacements)
         expected_annotations = parse_annotations(source, **replacements)
         source = expected_annotations.plain_source
@@ -123,8 +124,15 @@ def expect_offense(source, file = nil, severity: nil, chomp: false, **replacemen
         expect(actual_annotations).to eq(expected_annotations), ''
         expect(@offenses.map(&:severity).uniq).to eq([severity]) if severity
 
+        # Validate that all offenses have a range that formatters can display
+        expect do
+          @offenses.each { |offense| offense.location.source_line }
+        end.not_to raise_error, 'One of the offenses has a misconstructed range, for ' \
+                                'example if the offense is on line 1 and the source is empty'
+
         @offenses
       end
+      # rubocop:enable Metrics/AbcSize
 
       # rubocop:disable Metrics/AbcSize, Metrics/MethodLength, Metrics/CyclomaticComplexity
       def expect_correction(correction, loop: true, source: nil)

spec/rubocop/cop/style/copyright_spec.rb

@@ -93,12 +93,10 @@
       cop_config['AutocorrectNotice'] = '# Copyright (c) 2015 Acme Inc.'
 
       expect_offense(<<~RUBY)
-        ^ Include a copyright notice matching [...]
+        ^{} Include a copyright notice matching [...]
       RUBY
 
-      expect_correction(<<~RUBY)
-        # Copyright (c) 2015 Acme Inc.
-      RUBY
+      expect_no_corrections
     end
   end