Adds support for parent_rev option in #delete

lib/dropbox_api/endpoints/files/delete.rb

@@ -5,18 +5,26 @@ class Delete < DropboxApi::Endpoints::Rpc
     ResultType  = DropboxApi::Metadata::Resource
     ErrorType   = DropboxApi::Errors::DeleteError
 
+    include DropboxApi::OptionsValidator
+
     # Delete the file or folder at a given path.
     #
     # If the path is a folder, all its contents will be deleted too.
     #
     # A successful response indicates that the file or folder was deleted.
-    # The returned metadata will be the corresponding FileMetadata or
-    # FolderMetadata for the item at time of deletion, and not a
-    # DeletedMetadata object.
+    # The returned metadata will be the corresponding
+    # {DropboxApi::Metadata::File} or {DropboxApi::Metadata::Folder} for the
+    # item at time of deletion, and not a {DropboxApi::Metadata::Deleted} object.
     #
     # @param path [String] Path in the user's Dropbox to delete.
-    add_endpoint :delete do |path|
-      perform_request({
+    # @option parent_rev [String] Perform delete if given "rev" matches the
+    #   existing file's latest "rev". This field does not support deleting a
+    #   folder. If the given "rev" doesn't match, a
+    #   {DropboxApi::Errors::FileConflictError} will be raised.
+    add_endpoint :delete do |path, options = {}|
+      validate_options([:parent_rev], options)
+
+      perform_request options.merge({
         :path => path
       })
     end

spec/endpoints/files/delete_spec.rb

@@ -11,6 +11,12 @@
     expect(file.name).to eq("will_be_deleted.txt")
   end
 
+  it "wont' delete the file if `parent_rev` doesn't match", :cassette => "delete/invalid_parent_rev" do
+    expect {
+      @client.delete "#{path_prefix}/wont_be_deleted.txt", :parent_rev => "1c0576c68d6"
+    }.to raise_error(DropboxApi::Errors::FileConflictError)
+  end
+
   it "returns the deleted folder", :cassette => "delete/success_folder" do
     folder = @client.delete "#{path_prefix}/folder"
 

spec/support/dropbox_scaffold_builder.rb

@@ -62,6 +62,7 @@ def build_delete
     file_contents = "Tijuana, amigo."
 
     client.upload "#{path_prefix}/will_be_deleted.txt", file_contents
+    client.upload "#{path_prefix}/wont_be_deleted.txt", file_contents
     client.upload "#{path_prefix}/folder/a.txt", file_contents
     client.upload "#{path_prefix}/folder/b.txt", file_contents
   end