Better error reporting

Warnings are now printed using console.warn. The name of the current
component is included in more cases.

Also warn every time an atom is derefed in a lazy seq, and not just
the first.

src/reagent/debug.clj

@@ -8,6 +8,19 @@
   `(when (clojure.core/exists? js/console)
      (.log js/console ~@forms)))
 
+(defmacro warn
+  "Print with console.warn."
+  [& forms]
+  (when *assert*
+    `(when (clojure.core/exists? js/console)
+       (.warn js/console (str "Warning: " ~@forms)))))
+
+(defmacro warn-unless
+  [cond & forms]
+  (when *assert*
+    `(when (and (not ~cond) (clojure.core/exists? js/console))
+       (.warn js/console (str "Warning: " ~@forms)))))
+
 (defmacro println
   "Print string with console.log"
   [& forms]

src/reagent/impl/component.cljs

@@ -3,7 +3,7 @@
             [reagent.impl.batching :as batch]
             [reagent.ratom :as ratom]
             [reagent.interop :refer-macros [.' .!]]
-            [reagent.debug :refer-macros [dbg prn]]))
+            [reagent.debug :refer-macros [dbg prn dev?]]))
 
 (declare ^:dynamic *current-component*)
 
@@ -118,10 +118,10 @@
       (this-as c (apply f c args)))
     f))
 
-(def dont-wrap #{:cljsRender :render :componentFunction})
+(def dont-wrap #{:cljsRender :render :componentFunction :cljsName})
 
 (defn dont-bind [f]
-  (if (ifn? f)
+  (if (fn? f)
     (doto f
       (.! :__reactDontBind true))
     f))
@@ -149,10 +149,13 @@
 (defn add-obligatory [fun-map]
   (merge obligatory fun-map))
 
-(defn add-render [fun-map render-f]
-  (assoc fun-map
-    :cljsRender render-f
-    :render (:render static-fns)))
+(defn add-render [fun-map render-f name]
+  (let [fm (assoc fun-map
+                  :cljsRender render-f
+                  :render (:render static-fns))]
+    (if (dev?)
+      (assoc fm :cljsName (fn [] name))
+      fm)))
 
 (defn wrap-funs [fun-map]
   (let [render-fun (or (:componentFunction fun-map)
@@ -167,7 +170,7 @@
         name' (if (empty? name) (str (gensym "reagent")) name)
         fmap (-> fun-map
                  (assoc :displayName name')
-                 (add-render render-fun))]
+                 (add-render render-fun name'))]
     (reduce-kv (fn [m k v]
                  (assoc m k (get-wrapper k v name')))
                {} fmap)))
@@ -195,3 +198,12 @@
     (util/cache-react-class f res)
     (util/cache-react-class res res)
     f))
+
+(defn comp-name []
+  (if (dev?)
+    (let [n (some-> *current-component*
+                    (.' cljsName))]
+      (if-not (empty? n)
+        (str " (in " n ")")
+        ""))
+    ""))

src/reagent/impl/template.cljs

@@ -5,8 +5,8 @@
             [reagent.impl.batching :as batch]
             [reagent.ratom :as ratom]
             [reagent.interop :refer-macros [.' .!]]
-            [reagent.debug :refer-macros [dbg prn println log dev?]]))
-
+            [reagent.debug :refer-macros [dbg prn println log dev?
+                                          warn warn-unless]]))
 
 ;; From Weavejester's Hiccup, via pump:
 (def ^{:doc "Regular expression that parses a CSS-style id and class
@@ -149,18 +149,18 @@
   (let [[tag id class] (->> hiccup-tag name (re-matches re-tag) next)
         class' (when class
                  (string/replace class #"\." " "))]
-    (assert tag (str "Unknown tag: '" hiccup-tag "'"))
+    (assert tag (str "Invalid tag: '" hiccup-tag "'"
+                     (comp/comp-name)))
     #js{:name tag
         :id id
         :className class'}))
 
 (defn fn-to-class [f]
   (assert (ifn? f) (str "Expected a function, not " (pr-str f)))
-  (when (dev?)
-    (when (and (fn? f)
-               (some? (.' f :type)))
-      (log "warning: using native React classes directly is not supported: "
-           (.' f :type))))
+  (warn-unless (not (and (fn? f)
+                         (some? (.' f :type))))
+               "Using native React classes directly "
+               "is not supported: " (.' f :type) (comp/comp-name))
   (let [spec (meta f)
         withrender (assoc spec :component-function f)
         res (comp/create-class withrender)
@@ -215,10 +215,13 @@
             (make-element argv comp p first-child)))))))
 
 (defn vec-to-elem [v]
-  (assert (pos? (count v)) "Hiccup form should not be empty")
+  (assert (pos? (count v))
+          (str "Hiccup form should not be empty: "
+               (pr-str v) (comp/comp-name)))
   (let [tag (nth v 0)]
     (assert (valid-tag? tag)
-            (str "Invalid Hiccup form: " (pr-str v)))
+            (str "Invalid Hiccup form: "
+                 (pr-str v) (comp/comp-name)))
     (if-some [ne (native-element tag v)]
       ne
       (reag-element tag v))))
@@ -226,10 +229,9 @@
 (def seq-ctx #js{})
 
 (defn warn-on-deref [x]
-  (when-not (.' seq-ctx :warned)
-    (log "Warning: Reactive deref not supported in seq in "
-         (pr-str x))
-    (.! seq-ctx :warned true)))
+  (warn "Reactive deref not supported in lazy seq, it should be "
+        "wrapped in doall" (comp/comp-name) ". Value:\n"
+        (pr-str x)))
 
 (declare expand-seq)
 

src/reagent/impl/util.cljs

@@ -1,5 +1,5 @@
 (ns reagent.impl.util
-  (:require [reagent.debug :refer-macros [dbg log]]
+  (:require [reagent.debug :refer-macros [dbg log warn]]
             [reagent.interop :refer-macros [.' .!]]
             [clojure.string :as string]))
 
@@ -110,7 +110,7 @@
   (try
     (.' js/React unmountComponentAtNode node)
     (catch js/Object e
-      (do (log "Error unmounting:")
+      (do (warn "Error unmounting:")
           (log e)))))
 
 (defn render-component [comp container callback]

src/reagent/ratom.cljs

@@ -1,6 +1,6 @@
 (ns reagent.ratom
   (:refer-clojure :exclude [atom])
-  (:require-macros [reagent.debug :refer (dbg log dev?)])
+  (:require-macros [reagent.debug :refer (dbg log warn dev?)])
   (:require [reagent.impl.util :as util]))
 
 (declare ^:dynamic *ratom-context*)
@@ -162,10 +162,9 @@
   [src path]
   (if (satisfies? IDeref path)
     (do
-      (when (dev?)
-        (log (str "Calling cursor with an atom as the second arg is "
-                  "deprecated, in (cursor "
-                  src " " (pr-str path) ")")))
+      (warn "Calling cursor with an atom as the second arg is "
+            "deprecated, in (cursor "
+            src " " (pr-str path) ")")
       (RCursor. path src nil))
     (do
       (assert (or (satisfies? IDeref src)
@@ -325,8 +324,8 @@
   (-deref [this]
     (when (dev?)
       (when (and changed (some? *ratom-context*))
-        (log "warning: derefing stale wrap: "
-             (pr-str this))))
+        (warn "derefing stale wrap: "
+              (pr-str this))))
     state)
 
   IReset