1 files changed, 49 insertions, 0 deletions
diff --git a/lib/dslkeywords/file_backup.rb b/lib/dslkeywords/file_backup.rb
new file mode 100644
index 0000000..210804c
--- /dev/null
+++ b/lib/dslkeywords/file_backup.rb
@@ -0,0 +1,49 @@
+require 'digest'
+
+module RCM
+  # Mixin that provides file-backup helpers for resource classes.
+  # Included by BasicFile so all file/directory/symlink resources share
+  # the same backup logic.
+  module FileBackup
+    # TODO: Make protected?
+    def backup!(file_path, checksum = nil)
+      return if @without_backup
+
+      suffix = if ::File.file?(file_path)
+                 checksum.nil? ? Digest::SHA256.file(file_path).hexdigest : checksum
+               else
+                 Time.now.strftime('%s-%L')
+               end
+      make_backup!(file_path, suffix)
+    end
+
+    def different?(file_a, file_b)
+      checksum_a = Digest::SHA256.file(file_a).hexdigest
+      checksum_b = Digest::SHA256.file(file_b).hexdigest
+      [checksum_a != checksum_b, checksum_a, checksum_b]
+    end
+
+    private
+
+    def make_backup!(file_path, suffix)
+      backup_dir = create_backup_directory!(file_path)
+      backup_path = "#{backup_dir}/#{::File.basename(file_path)}.#{suffix}"
+      return if ::File.exist?(backup_path)
+
+      do? "Backing up #{file_path} -> #{backup_path}" do
+        ::File.rename(file_path, backup_path)
+      end
+    end
+
+    def create_backup_directory!(file_path)
+      backup_dir = "#{::File.dirname(file_path)}/.rcmbackup"
+      return backup_dir if ::File.directory?(backup_dir)
+
+      do? "Creating backup directory #{backup_dir}" do
+        Dir.mkdir(backup_dir)
+      end
+
+      backup_dir
+    end
+  end
+end