Add class method API to Kemal::Base

spec/application_mode_spec.cr

@@ -0,0 +1,27 @@
+require "./spec_helper"
+
+private class MyApp < Kemal::Application
+  get "/route1" do |env|
+    "Route 1"
+  end
+
+  get "/route2" do |env|
+    "Route 2"
+  end
+end
+
+describe MyApp do
+  it "matches the correct route" do
+    request = HTTP::Request.new("GET", "/route2")
+    client_response = call_request_on_app(MyApp.new, request)
+    client_response.body.should eq("Route 2")
+  end
+
+  it "doesn't allow a route declaration start without /" do
+    expect_raises Kemal::Exceptions::InvalidPathStartException, "Route declaration get \"route\" needs to start with '/', should be get \"/route\"" do
+      MyApp.new.get "route" do |env|
+        "Route 1"
+      end
+    end
+  end
+end