Use danger-gitlab to auto review merge requests

Given failures to check simple things in the past, like if a changelog
was present, danger-gitlab is introduced to automatically perform these
tasks.

A warning was added when a changelog entry is skipped, and failures are
due to missing MR descriptions or gitaly-proto versions being incorrect.

To force diff highlighting to work, `.gitattributes` was added.

1 files changed, 19 insertions, 0 deletions

diff --git a/Dangerfile b/Dangerfile
new file mode 100644
index 000000000..c1ffd180f
--- /dev/null
+++ b/Dangerfile
@@ -0,0 +1,19 @@
+unless git.modified_files.include?("CHANGELOG.md")
+  warn("This MR is missing a CHANGLOG entry")
+end
+
+fail("Please provide a MR description") if gitlab.mr_body.empty?
+
+VENDOR_JSON = 'vendor/vendor.json'
+fail("Expected #{VENDOR_JSON} to exist") unless File.exist?(VENDOR_JSON)
+
+if git.modified_files.include?(VENDOR_JSON)
+  require 'json'
+  parsed_json = JSON.parse(File.read(VENDOR_JSON))
+
+  proto = parsed_json["package"]&.find { |h| h["path"].start_with?("gitlab.com/gitlab-org/gitaly-proto") }
+
+  unless proto["version"] && proto["version"] =~ /\Av\d+\./
+    fail("gitaly-proto version is incorrect")
+  end
+end