1 files changed, 20 insertions, 13 deletions
diff --git a/Library/Formula/pgtap.rb b/Library/Formula/pgtap.rb
index 16415304a..fc5149253 100644
--- a/Library/Formula/pgtap.rb
+++ b/Library/Formula/pgtap.rb
@@ -1,25 +1,32 @@
 require 'formula'
 
+class PostgresqlInstalled < Requirement
+  def message; <<-EOS.undent
+    PostgresQL is required to install.
+
+    You can install this with:
+      brew install postgresql
+
+    Or you can use an official installer from:
+      http://www.postgresql.org/
+    EOS
+  end
+  def satisfied?
+    which 'pg_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Pgtap < Formula
   url 'http://pgfoundry.org/frs/download.php/2701/pgtap-0.24.tar.bz2'
   homepage 'http://pgtap.org'
   md5 '9d0360c87fca0ddf3ca9da49b9b71947'
 
-  skip_clean :all
+  depends_on PostgresqlInstalled.new
 
   def install
-    unless which 'pg_config'
-      opoo "No pg_config was detected."
-      puts <<-EOS.undent
-        pg_top requires postgresql in order to compile, but pg_config was not
-        found. This install will likely fail.
-
-        You can install this with:
-          brew install postgresql
-        or by using a package installer from the PostgreSQL project itself.
-      EOS
-    end
-
     system "make install"
     bin.install %w(bbin/pg_prove bbin/pg_tapgen)
   end