diff --git a/src/cloact/impl/component.cljs b/src/cloact/impl/component.cljs
index dde9c6f..81827e2 100644
--- a/src/cloact/impl/component.cljs
+++ b/src/cloact/impl/component.cljs
@@ -208,6 +208,7 @@
 
 (defn create-class
   [body]
+  (assert (map? body))
   (let [spec (cljsify body)
         res (.createClass React spec)
         f (fn [& args]
diff --git a/src/cloact/impl/template.cljs b/src/cloact/impl/template.cljs
index 6592492..9f2aef3 100644
--- a/src/cloact/impl/template.cljs
+++ b/src/cloact/impl/template.cljs
@@ -32,7 +32,8 @@
             [id class'])]))
 
 (def attr-aliases {"class" "className"
-                   "for" "htmlFor"})
+                   "for" "htmlFor"
+                   "charset" "charSet"})
 
 (defn undash-prop-name [n]
   (let [undashed (dash-to-camel n)]
@@ -114,6 +115,7 @@
 (declare wrapper)
 
 (defn fn-to-class [f]
+  (assert (fn? f))
   (let [spec (meta f)
         withrender (merge spec {:render f})
         res (cloact.core/create-class withrender)]
@@ -130,6 +132,7 @@
                (fn-to-class x)))))
 
 (defn vec-to-comp [v]
+  (assert (pos? (count v)))
   (let [[tag props] v
         c (.-cljsReactClass (as-class tag))
         obj (js-obj)]
diff --git a/test/demo.cljs b/test/demo.cljs
index 3bb2406..69d67a9 100644
--- a/test/demo.cljs
+++ b/test/demo.cljs
@@ -38,11 +38,12 @@
                "range" "nil\\?" "int" "or" "->" "%"])
 
 (defn syntaxify [src]
+  ;; quick and (very) dirty syntax coloring
   (let [sep "\\][(){} \\t\\n"
         str-p "\"[^\"]*\""
         keyw-p (str ":[^" sep "]+")
         res-p (string/join "|" (map #(str "\\b" % "(?=[" sep "])") builtins))
-        any-p (str "[^" sep "]+|.|\\n") ;; ".|\\n"
+        any-p (str "[^" sep "]+|.|\\n")
         patt (re-pattern (str "("
                               (string/join ")|(" [str-p keyw-p res-p any-p])
                               ")"))]
@@ -54,18 +55,18 @@
               res [:b res]
               :else s)))))
 
-(defn src-for [{:keys [defs]}]
+(defn src-for [defs]
   [:pre (syntaxify (src-for-names defs))])
 
-(defn demo-component [props]
+(defn demo-component [{:keys [comp defs]}]
   [:div
-   (when (:comp props)
+   (when comp
      [:div.demo-example
       [:h3.demo-heading "Example"]
-      [(:comp props)]])
+      [comp]])
    [:div.demo-source
     [:h3.demo-heading "Source"]
-    [src-for props]]])
+    (src-for defs)]])
 
 (defn simple-component []
   [:div
@@ -165,7 +166,8 @@
   [:div
    [:h2 "Introduction to Cloact"]
 
-   [:p "Cloact provides a minimalistic interface between "
+   [:p [:a {:href "https://github.com/holmsand/cloact"} "Cloact"]
+    " provides a minimalistic interface between "
     [:a {:href "https://github.com/clojure/clojurescript"} "ClojureScript"]
     " and " [:a {:href "http://facebook.github.io/react/"} "React"]
     ". It allows you to define React components using nothing but