adjust the specs

Fixes #6109

logstash-core/lib/logstash/plugins/registry.rb

@@ -132,12 +132,18 @@ module LogStash module Plugins
 
     def lookup(type, plugin_name, &block)
       plugin = get(type, plugin_name)
-
       # Assume that we have a legacy plugin
       if plugin.nil?
         begin
           path = "logstash/#{type}s/#{plugin_name}"
-          require path rescue LoadError # Plugin might be already defined in the current scope
+
+          begin
+            require path
+          rescue LoadError
+            # Plugin might be already defined in the current scope
+            # This scenario often happen in test when we write an adhoc class
+          end
+
           klass = namespace_lookup(type, plugin_name)
           plugin = lazy_add(type, plugin_name, klass)
         rescue => e

logstash-core/spec/logstash/agent_spec.rb

@@ -411,7 +411,7 @@ describe LogStash::Agent do
     # We need to create theses dummy classes to know how many
     # events where actually generated by the pipeline and successfully send to the output.
     # Theses values are compared with what we store in the metric store.
-    class DummyOutput2 < DummyOutput; end
+    class DummyOutput2 < LogStash::Outputs::DummyOutput; end
 
     let!(:dummy_output) { DummyOutput.new }
     let!(:dummy_output2) { DummyOutput2.new }

logstash-core/spec/logstash/plugin_spec.rb

@@ -31,21 +31,10 @@ describe LogStash::Plugin do
     class LogStash::Filters::LadyGaga < LogStash::Filters::Base
       config_name "lady_gaga"
     end
+
     expect(LogStash::Plugin.lookup("filter", "lady_gaga")).to eq(LogStash::Filters::LadyGaga)
   end
 
-  describe "plugin signup in the registry" do
-
-    let(:registry) { LogStash::PluginRegistry }
-
-    it "should be present in the registry" do
-      class LogStash::Filters::MyPlugin < LogStash::Filters::Base
-        config_name "my_plugin"
-      end
-      expect(registry.exists?(:filter, "my_plugin")).to eq(true)
-    end
-  end
-
   describe "#inspect" do
     class LogStash::Filters::MyTestFilter < LogStash::Filters::Base
       config_name "param1"

logstash-core/spec/logstash/plugins/registry_spec.rb

@@ -10,6 +10,13 @@ class LogStash::Inputs::Dummy < LogStash::Inputs::Base
   def register; end
 end
 
+
+class LogStash::Inputs::NewPlugin < LogStash::Inputs::Base
+  config_name "new_plugin"
+
+  def register; end
+end
+
 describe LogStash::Plugins::Registry do
   let(:registry) { described_class.new }
 
@@ -22,18 +29,13 @@ describe LogStash::Plugins::Registry do
     end
 
     it "should raise an error if can not find the plugin class" do
-      expect(LogStash::Registry::Plugin).to receive(:new).with("input", "elastic").and_return(plugin)
-      expect(plugin).to receive(:path).and_return("logstash/input/elastic").twice
-      expect(plugin).to receive(:installed?).and_return(true)
-      expect { registry.lookup("input", "elastic") }.to raise_error(LoadError)
+      expect { registry.lookup("input", "do-not-exist-elastic") }.to raise_error(LoadError)
     end
 
     it "should load from registry is already load" do
-      registry.lookup("input", "stdin")
-      expect(registry).to receive(:registered?).and_return(true).once
-      registry.lookup("input", "stdin")
-      internal_registry = registry.instance_variable_get("@registry")
-      expect(internal_registry).to include("logstash/inputs/stdin" => LogStash::Inputs::Stdin)
+      expect(registry.exists?(:input, "stdin")).to be_falsey
+      expect { registry.lookup("input", "new_plugin") }.to change { registry.size }.by(1)
+      expect { registry.lookup("input", "new_plugin") }.not_to change { registry.size }
     end
   end
 
@@ -49,4 +51,15 @@ describe LogStash::Plugins::Registry do
       expect { registry.lookup("input", "elastic") }.to raise_error(LoadError)
     end
   end
+
+  context "when loading plugin manually configured" do
+    it "should return the plugin" do
+      class SimplePlugin
+      end
+
+      expect { registry.lookup("filter", "simple_plugin") }.to raise_error(LoadError)
+      registry.add(:filter, "simple_plugin", SimplePlugin)
+      expect(registry.lookup("filter", "simple_plugin")).to eq(SimplePlugin)
+    end
+  end
 end