Add tests for LogStash::Codec::Delegator

Fixes #10614

logstash-core/spec/logstash/codecs/delegator_spec.rb

@@ -0,0 +1,85 @@
+# encoding: utf-8
+require "spec_helper"
+
+class LogStash::Codecs::MockCodec < LogStash::Codecs::Base
+  config_name "my_name"
+
+  def multi_encode(e)
+  end
+
+  def encode(e)
+  end
+
+  def decode(e)
+    for i in e.split('|')
+      yield i
+    end
+  end
+end
+
+describe LogStash::Codecs::Delegator do
+  let(:collector)   { LogStash::Instrument::Collector.new }
+  let(:metric) { LogStash::Instrument::Metric.new(collector) }
+  let(:codec) { LogStash::Codecs::MockCodec.new }
+
+  subject do
+    delegator = described_class.new(codec)
+    delegator.metric = metric.namespace([:stats, :pipelines, :main, :plugins, :codecs, :my_id])
+    delegator
+  end
+
+  let(:snapshot_store) { collector.snapshot_metric.metric_store }
+
+  let(:snapshot_metric) { snapshot_store.get_shallow(:stats) }
+
+  describe "#encode" do
+    it "should delegate call to codec" do
+      expect(codec).to receive(:encode).with("abcdef")
+      subject.encode("abcdef")
+    end
+
+    it "should increment metrics" do
+      subject.encode("test")
+      expect(snapshot_metric[:pipelines][:main][:plugins][:codecs][:my_id][:encode][:writes_in].value).to eq(1)
+    end
+  end
+
+  describe "#multi_encode" do
+    it "should delegate call to codec" do
+      expect(codec).to receive(:multi_encode).with(%w(ay laa))
+      subject.multi_encode(%w(ay laa))
+    end
+
+    it "should increment metrics" do
+      subject.multi_encode(%w(ay test))
+      expect(snapshot_metric[:pipelines][:main][:plugins][:codecs][:my_id][:encode][:writes_in].value).to eq(2)
+    end
+  end
+
+  describe "#decode" do
+    it "should delegate call to codec" do
+      expect(codec).to receive(:decode).with("ayooooo")
+      subject.decode("ayooooo")
+    end
+
+    it "should increment metrics" do
+      subject.decode("bird|law") {}
+      expect(snapshot_metric[:pipelines][:main][:plugins][:codecs][:my_id][:decode][:writes_in].value).to eq(1)
+      expect(snapshot_metric[:pipelines][:main][:plugins][:codecs][:my_id][:decode][:out].value).to eq(2)
+    end
+  end
+
+  describe "#close" do
+    it "should delegate call to codec" do
+      expect(codec).to receive(:close)
+      subject.close
+    end
+  end
+
+  describe "#plugin_type" do
+    it "should delegate call to codec" do
+      expect(codec).to receive(:plugin_type)
+      subject.plugin_type
+    end
+  end
+end