brew-test-bot: better name hash and url builds.

Library/Contributions/cmd/brew-test-bot.rb

@@ -145,6 +145,10 @@ class Test
       git('symbolic-ref HEAD').gsub('refs/heads/', '').strip
     end
 
+    def single_commit? start_revision, end_revision
+      git("rev-list --count #{start_revision}..#{end_revision}").to_i == 1
+    end
+
     @category = __method__
     @start_branch = current_branch
 
@@ -160,7 +164,8 @@ class Test
     end
 
     if @hash == 'HEAD'
-      if diff_start_sha1 == diff_end_sha1
+      if diff_start_sha1 == diff_end_sha1 or \
+        single_commit?(diff_start_sha1, diff_end_sha1)
         @name = diff_end_sha1
       else
         @name = "#{diff_start_sha1}-#{diff_end_sha1}"
@@ -174,7 +179,14 @@ class Test
       test "git checkout #{current_sha1}"
       test "brew pull --clean #{@url}"
       diff_end_sha1 = current_sha1
-      @name = "#{@url}-#{diff_end_sha1}"
+      @short_url = @url.gsub('https://github.com/', '')
+      if @short_url.include? '/commit/'
+        # 7 characters should be enough for a commit (not 40).
+        @short_url.gsub!(/(commit\/\w{7}).*/, '\1')
+        @name = @short_url
+      else
+        @name = "#{@short_url}-#{diff_end_sha1}"
+      end
     else
       diff_start_sha1 = diff_end_sha1 = current_sha1
       @name = "#{@formulae.first}-#{diff_end_sha1}"