Fix infer externs problem in with-let macro, fixes #420

project.clj

@@ -54,7 +54,8 @@
                 :output-to "target/cljsbuild/client/public/js/main.js"
                 :npm-deps false
                 :asset-path "js/out"
-                :checked-arrays :warn}}
+                :checked-arrays :warn
+                :infer-externs true}}
 
     {:id "client-npm"
      :source-paths ["demo"]
@@ -79,7 +80,8 @@
                 :output-to "target/cljsbuild/test/main.js"
                 :npm-deps false
                 :aot-cache true
-                :checked-arrays :warn}}
+                :checked-arrays :warn
+                :infer-externs true}}
 
     {:id "test-npm"
      :source-paths ["test"]

src/reagent/ratom.clj

@@ -63,7 +63,7 @@
         asserting (if *assert* true false)]
     `(let [~v (reagent.ratom/with-let-values ~k)]
        (when ~asserting
-         (when-some [c# reagent.ratom/*ratom-context*]
+         (when-some [^clj c# reagent.ratom/*ratom-context*]
            (when (== (.-generation ~v) (.-ratomGeneration c#))
              (d/error "Warning: The same with-let is being used more "
                       "than once in the same reactive context."))

test/reagenttest/testwithlet.cljs

@@ -6,6 +6,10 @@
              :refer [flush track track! dispose!] :refer-macros [with-let]]
             [clojure.walk :as w]))
 
+;; Test code generated from with-let macro
+;; https://github.com/reagent-project/reagent/issues/420
+(set! *warn-on-infer* true)
+
 (defn fixture [f]
   (set! rv/debug true)
   (f)