Check the latest version from the LATEST text file

lib/up2date.rb

@@ -20,6 +20,7 @@ module SlackBuilder
     end
   end
 
+  # Reads the list fo tags from the GitHub API.
   class GitHub < Repository
     GITHUB_QUERY = <<~GQL
       query ($name: String!, $owner: String!) {
@@ -66,6 +67,7 @@ module SlackBuilder
     end
   end
 
+  # Request the latest version from the packagist API.
   class Packagist < Repository
     def initialize(vendor, name)
       super()
@@ -74,7 +76,6 @@ module SlackBuilder
       @name = name
     end
 
-    # Request the latest version from the packagist API.
     def latest
       full_name = [@vendor, @name].join '/'
       uri = URI "https://repo.packagist.org/p2/#{full_name}.json"
@@ -85,6 +86,22 @@ module SlackBuilder
     end
   end
 
+  # Reads a remote LATEST file.
+  class LatestText < Repository
+    def initialize(latest_url)
+      super()
+
+      @latest_url = URI latest_url
+    end
+
+    def latest
+      response = Net::HTTP.get @latest_url, {
+        'content-type' => 'text/plain'
+      }
+      response.strip
+    end
+  end
+
   module_function
 
   # Checks if there is a new version for the package and returns the latest