cask/audit: detect tag from URL

Library/Homebrew/cask/audit.rb

@@ -468,8 +468,9 @@ module Cask
       user, repo = get_repo_data(%r{https?://github\.com/([^/]+)/([^/]+)/?.*}) if @online
       return if user.nil?
 
-      # TODO: Detect tag from URL instead of using `cask.version`.
-      error = SharedAudits.github_release(user, repo, cask.version, cask: cask)
+      tag = SharedAudits.github_tag_from_url(cask.url)
+      tag ||= cask.version
+      error = SharedAudits.github_release(user, repo, tag, cask: cask)
       add_error error if error
     end
 
@@ -481,7 +482,9 @@ module Cask
 
       odebug "Auditing GitLab prerelease"
 
-      error = SharedAudits.gitlab_release(user, repo, cask.version)
+      tag = SharedAudits.gitlab_tag_from_url(cask.url)
+      tag ||= cask.version
+      error = SharedAudits.gitlab_release(user, repo, tag)
       add_error error if error
     end
 

Library/Homebrew/dev-cmd/audit.rb

@@ -784,9 +784,7 @@ module Homebrew
         owner = Regexp.last_match(1)
         repo = Regexp.last_match(2)
 
-        tag = url.match(%r{^https://gitlab\.com/[\w-]+/[\w-]+/-/archive/([^/]+)/})
-                 .to_a
-                 .second
+        tag = SharedAudits.gitlab_tag_from_url(url)
         tag ||= stable.specs[:tag]
         tag ||= stable.version
 
@@ -797,12 +795,7 @@ module Homebrew
       when %r{^https://github.com/([\w-]+)/([\w-]+)}
         owner = Regexp.last_match(1)
         repo = Regexp.last_match(2)
-        tag = url.match(%r{^https://github\.com/[\w-]+/[\w-]+/archive/([^/]+)\.(tar\.gz|zip)$})
-                 .to_a
-                 .second
-        tag ||= url.match(%r{^https://github\.com/[\w-]+/[\w-]+/releases/download/([^/]+)/})
-                   .to_a
-                   .second
+        tag = SharedAudits.github_tag_from_url(url)
         tag ||= formula.stable.specs[:tag]
 
         if @online

Library/Homebrew/utils/shared_audits.rb

@@ -164,4 +164,22 @@ module SharedAudits
 
     "Bitbucket repository not notable enough (<30 forks and <75 watchers)"
   end
+
+  def github_tag_from_url(url)
+    url = url.to_s
+    tag = url.match(%r{^https://github\.com/[\w-]+/[\w-]+/archive/([^/]+)\.(tar\.gz|zip)$})
+             .to_a
+             .second
+    tag ||= url.match(%r{^https://github\.com/[\w-]+/[\w-]+/releases/download/([^/]+)/})
+               .to_a
+               .second
+    tag
+  end
+
+  def gitlab_tag_from_url(url)
+    url = url.to_s
+    url.match(%r{^https://gitlab\.com/[\w-]+/[\w-]+/-/archive/([^/]+)/})
+       .to_a
+       .second
+  end
 end