Danger: Exclude generated protobuf files in sizetoon-danger-exclude-gen-proto

This change adds a lightly adjusted version of the changes_size rule.
This version excludes the generated protobuf files *.pb.go and *_pb.rb.

2 files changed, 17 insertions, 1 deletions

diff --git a/Dangerfile b/Dangerfile
index 616556b1a..39c6730e2 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -14,5 +14,6 @@ Gitlab::Dangerfiles.for_project(self) do |gitlab_dangerfiles|
     danger.import_dangerfile(path: "danger/rules/#{rule}")
   end
 
-  gitlab_dangerfiles.import_defaults
+  gitlab_dangerfiles.import_plugins
+  gitlab_dangerfiles.import_dangerfiles(except: %w[changes_size])
 end
diff --git a/danger/rules/changes_size/Dangerfile b/danger/rules/changes_size/Dangerfile
new file mode 100644
index 000000000..841b373f7
--- /dev/null
+++ b/danger/rules/changes_size/Dangerfile
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+thresholds = helper.config.code_size_thresholds
+
+lines_changed = (git.added_files + git.modified_files).sum do |file|
+  next 0 if file.end_with?('.pb.go') || file.end_with?('_pb.rb')
+
+  git.info_for_file(file)[:insertions]
+end
+
+if lines_changed > thresholds[:high]
+  warn "This merge request is definitely too big (#{lines_changed} lines changed), please split it into multiple merge requests."
+elsif lines_changed > thresholds[:medium]
+  warn "This merge request is quite big (#{lines_changed} lines changed), please consider splitting it into multiple merge requests."
+end