[rubygems/rubygems] Add `gitlab:` Git source shorthand

This new shorthand, similar to the existing `github:` shorthand, adds
support for Gitlab repositories with a notable difference. Gitlab
projects may be organized into projects and subprojects. An example
Ruby gem exists at:

https://gitlab.com/gitlab-org/analytics-section/product-analytics/gl-application-sdk-rb

With the new shorthand, a user may install this gem from its repository
by adding:

```ruby
gem "gitlab-sdk", gitlab: "gitlab-org/analytics-section/product-analytics/gl-application-sdk-rb"
```

As with the `github:` shorthand, a supplied string with no `/` will be
interpreted as `example/example`.

Also in keeping with the utility of the `github:` shorthand, the new
`gitlab:` shorthand also supports Merge Request URLs.

```ruby
gem "gitlab-sdk", gitlab: "https://gitlab.com/gitlab-org/analytics-section/product-analytics/gl-application-sdk-rb/-/merge_requests/27"
```

The `gitlab:` gem source shortcut is modeled on the existing `github:`
shortcut, so the new specs mimic the existing examples.

https://github.com/rubygems/rubygems/commit/f4399018c0

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/bundler/dsl.rb b/lib/bundler/dsl.rb
index 7b342c594a..6af80fb31f 100644
--- a/lib/bundler/dsl.rb
+++ b/lib/bundler/dsl.rb
@@ -19,6 +19,7 @@ module Bundler
                     platform platforms type source install_if gemfile force_ruby_platform].freeze
 
     GITHUB_PULL_REQUEST_URL = %r{\Ahttps://github\.com/([A-Za-z0-9_\-\.]+/[A-Za-z0-9_\-\.]+)/pull/(\d+)\z}
+    GITLAB_MERGE_REQUEST_URL = %r{\Ahttps://gitlab\.com/([A-Za-z0-9_\-\./]+)/-/merge_requests/(\d+)\z}
 
     attr_reader :gemspecs, :gemfile
     attr_accessor :dependencies
@@ -308,6 +309,20 @@ module Bundler
         repo_name ||= user_name
         "https://#{user_name}@bitbucket.org/#{user_name}/#{repo_name}.git"
       end
+
+      git_source(:gitlab) do |repo_name|
+        if repo_name =~ GITLAB_MERGE_REQUEST_URL
+          {
+            "git" => "https://gitlab.com/#{$1}.git",
+            "branch" => nil,
+            "ref" => "refs/merge-requests/#{$2}/head",
+            "tag" => nil,
+          }
+        else
+          repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
+          "https://gitlab.com/#{repo_name}.git"
+        end
+      end
     end
 
     def with_source(source)