add gelfify filter test

test/logstash/filters/test_gelfify.rb

@@ -0,0 +1,58 @@
+require "rubygems"
+require File.join(File.dirname(__FILE__), "..", "minitest")
+
+require "logstash/loadlibs"
+require "logstash"
+require "logstash/filters"
+require "logstash/filters/gelfify"
+require "logstash/event"
+
+describe LogStash::Filters::Gelfify do
+  before do
+    @filter = LogStash::Filters.from_name("gelfify", {})
+    @typename = "gelf"
+  end
+
+  def config(cfg = {})
+    cfg["type"] = @typename
+    cfg.each_key do |key|
+      if cfg[key].is_a?(String)
+        cfg[key] = [cfg[key]]
+      end
+    end
+
+    @filter = LogStash::Filters::Gelfify.new(cfg)
+    @filter.register
+  end # def config
+
+  test "gelfify, severity field" do
+    config
+
+    LogStash::Filters::Gelfify::SYSLOG_LEVEL_MAP.each do |old, new|
+      event = LogStash::Event.new
+      event.type = @typename
+      event["severity"] = old.to_s
+      @filter.filter(event)
+      assert_equal(event["GELF_severity"], new)
+    end
+  end # gelfify, severity field
+
+  test "gelfify, random severity field" do
+    config
+
+    event = LogStash::Event.new
+    event.type = @typename
+    event["severity"] = "xyz"
+    @filter.filter(event)
+    assert_equal(event["GELF_severity"], nil)
+  end # gelfify, random severity field
+
+  test "gelfify, missing severity field" do
+    config
+
+    event = LogStash::Event.new
+    event.type = @typename
+    @filter.filter(event)
+    assert_equal(event["GELF_severity"], nil)
+  end # gelfify, missing severity field
+end # Test 'gelfify' filter