Bust erblilnt cache on rubocop config changes via linter checksum

lib/erb_lint/cache.rb

@@ -67,6 +67,10 @@ def clear
       FileUtils.rm_r(@cache_dir)
     end
 
+    def set_runner_checksum(checksum)
+      @runner_checksum = checksum
+    end
+
     private
 
     attr_reader :config, :hits, :new_results
@@ -76,7 +80,7 @@ def checksum(filename, file_content)
       mode = File.stat(filename).mode
 
       digester.update(
-        "#{mode}#{config.to_hash}#{ERBLint::VERSION}#{file_content}",
+        "#{mode}#{config.to_hash}#{ERBLint::VERSION}#{@runner_checksum}#{file_content}",
       )
       digester.hexdigest
     rescue Errno::ENOENT

lib/erb_lint/cli.rb

@@ -79,6 +79,9 @@ def run(args = ARGV)
       reporter.preview
 
       runner = ERBLint::Runner.new(file_loader, @config, @options[:disable_inline_configs])
+
+      @cache.set_runner_checksum(runner.checksum) if cache?
+
       file_content = nil
 
       lint_files.each do |filename|

lib/erb_lint/linter.rb

@@ -70,6 +70,12 @@ def clear_offenses
       @offenses = []
     end
 
+    # Allows linters to specify their own checksums to bust caches, etc.
+    # for dependencies and things not represented in the erblint config.
+    def checksum
+      nil
+    end
+
     private
 
     def update_offense_status(processed_source)

lib/erb_lint/linters/rubocop.rb

@@ -63,6 +63,15 @@ def autocorrect(processed_source, offense)
         end
       end
 
+      def checksum
+        digester = Digest::SHA1.new
+        gemfile_lock = File.read("Gemfile.lock") if File.exist?("Gemfile.lock")
+        digester.update(
+          "#{gemfile_lock}#{@rubocop_config.to_hash}"
+          )
+        digester.hexdigest
+      end
+
       private
 
       def descendant_nodes(processed_source)

lib/erb_lint/runner.rb

@@ -42,6 +42,15 @@ def restore_offenses(offenses)
       @offenses.concat(offenses)
     end
 
+    def checksum
+      digester = Digest::SHA1.new
+      @linters.each do |linter|
+        linter_checksum = linter.checksum
+        digester.update(linter_checksum) if linter_checksum
+      end
+      digester.hexdigest
+    end
+
     private
 
     def enable_inline_configs?