[chore] add mdatagen extension lifecycle tests

cmd/mdatagen/main.go

@@ -187,6 +187,9 @@ func templatize(tmplFile string, md metadata) *template.Template {
 				"isReceiver": func() bool {
 					return md.Status.Class == "receiver"
 				},
+				"isExtension": func() bool {
+					return md.Status.Class == "extension"
+				},
 				"skipLifecycle": func() bool {
 					return md.Tests.SkipLifecycle
 				},

cmd/mdatagen/templates/component_test.go.tmpl

@@ -23,6 +23,9 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumertest"
 	"go.opentelemetry.io/collector/receiver"
 	"go.opentelemetry.io/collector/receiver/receivertest"
+{{ end }}
+{{ if isExtension }}
+	"go.opentelemetry.io/collector/extension/extensiontest"
 {{ end }}
 	"go.opentelemetry.io/collector/confmap/confmaptest"
 {{ if or (isExporter) (isProcessor) }}
@@ -299,3 +302,39 @@ func Test_ComponentLifecycle(t *testing.T) {
 	}
 }
 {{ end }}
+
+{{ if isExtension }}
+func Test_ComponentLifecycle(t *testing.T) {
+	factory := NewFactory()
+
+	cm, err := confmaptest.LoadConf("metadata.yaml")
+	require.NoError(t, err)
+	cfg := factory.CreateDefaultConfig()
+	sub, err := cm.Sub("tests::config")
+	require.NoError(t, err)
+	require.NoError(t, component.UnmarshalConfig(sub, cfg))
+
+	t.Run("shutdown", func(t *testing.T) {
+		e, err := factory.CreateExtension(context.Background(), extensiontest.NewNopCreateSettings(), cfg)
+		require.NoError(t, err)
+		err = e.Shutdown(context.Background())
+		require.NoError(t, err)
+	})
+
+	t.Run("lifecycle", func(t *testing.T) {
+		{{ if skipLifecycle }}
+		// TODO support lifecycle
+		t.SkipNow()
+		{{ end }}
+		firstExt, err := factory.CreateExtension(context.Background(), extensiontest.NewNopCreateSettings(), cfg)
+		require.NoError(t, err)
+		require.NoError(t, firstExt.Start(context.Background(), newAssertNoErrorHost(t)))
+		require.NoError(t, firstExt.Shutdown(context.Background()))
+
+		secondExt, err := factory.CreateExtension(context.Background(), extensiontest.NewNopCreateSettings(), cfg)
+		require.NoError(t, err)
+		require.NoError(t, secondExt.Start(context.Background(), newAssertNoErrorHost(t)))
+		require.NoError(t, secondExt.Shutdown(context.Background()))
+	})
+}
+{{ end }}

extension/headerssetterextension/metadata.yaml

@@ -10,3 +10,5 @@ status:
   - sumo
   codeowners:
     active: [jpkrohling]
+tests:
+  config: