initialize support for versioning as requested, per route -- not finished yet

Former-commit-id: ade66610125f06a0b5ce3e90bcafe349f216a616

versioning/versioning_test.go

@@ -0,0 +1,49 @@
+package versioning_test
+
+import (
+	"testing"
+
+	"github.com/kataras/iris"
+	"github.com/kataras/iris/httptest"
+	"github.com/kataras/iris/versioning"
+)
+
+func notFoundHandler(ctx iris.Context) {
+	ctx.NotFound()
+}
+
+const (
+	v10Response = "v1.0 handler"
+	v2Response  = "v2.x handler"
+)
+
+func sendHandler(contents string) iris.Handler {
+	return func(ctx iris.Context) {
+		ctx.WriteString(contents)
+	}
+}
+
+func TestHandler(t *testing.T) {
+	app := iris.New()
+
+	userAPI := app.Party("/api/user")
+	userAPI.Get("/", versioning.Handler(versioning.Map{
+		"1.0":               sendHandler(v10Response),
+		">= 2, < 3":         sendHandler(v2Response),
+		versioning.NotFound: notFoundHandler,
+	}))
+
+	e := httptest.New(t, app)
+
+	e.GET("/api/user").WithHeader(versioning.AcceptVersionHeaderKey, "1").Expect().
+		Status(iris.StatusOK).Body().Equal(v10Response)
+	e.GET("/api/user").WithHeader(versioning.AcceptVersionHeaderKey, "2.0").Expect().
+		Status(iris.StatusOK).Body().Equal(v2Response)
+	e.GET("/api/user").WithHeader(versioning.AcceptVersionHeaderKey, "2.1").Expect().
+		Status(iris.StatusOK).Body().Equal(v2Response)
+	e.GET("/api/user").WithHeader(versioning.AcceptVersionHeaderKey, "2.9.9").Expect().
+		Status(iris.StatusOK).Body().Equal(v2Response)
+
+	e.GET("/api/user").WithHeader(versioning.AcceptVersionHeaderKey, "3.0").Expect().
+		Status(iris.StatusNotFound).Body().Equal("Not Found")
+}