Implement #439, make RAtom print output readable

CHANGELOG.md

@@ -6,6 +6,11 @@
 defined `:class` ([#479](https://github.com/reagent-project/reagent/pull/479))
 - Fix using `:className` property together with keyword class shortcut ([#433](https://github.com/reagent-project/reagent/issues/433))
 - Fix incorrect missing React key warnings with `:>` ([#399](https://github.com/reagent-project/reagent/issues/399))
+- Change RAtom (all types) print format to be readable using ClojureScript reader,
+similar to normal Atom ([#439](https://github.com/reagent-project/reagent/issues/439))
+    - Old print output: `#<Atom: 0>`
+    - New print output: `#object[clojure.ratom.RAtom {:val 0}]`
+    - Still not readable by default, requires custom reader for `object` tag.
 
 ## 0.10.0 (2020-03-06)
 

src/reagent/ratom.cljs

@@ -102,10 +102,10 @@
           (f k this old new))
         (recur (+ 2 i))))))
 
-(defn- pr-atom [a writer opts s]
-  (-write writer (str "#<" s " "))
-  (pr-writer (binding [*ratom-context* nil] (-deref a)) writer opts)
-  (-write writer ">"))
+(defn- pr-atom [a writer opts s v]
+  (-write writer (str "#object[reagent.ratom." s " "))
+  (pr-writer (binding [*ratom-context* nil] v) writer opts)
+  (-write writer "]"))
 
 
 ;;; Queueing
@@ -169,7 +169,7 @@
   (-meta [_] meta)
 
   IPrintWithWriter
-  (-pr-writer [a w opts] (pr-atom a w opts "Atom:"))
+  (-pr-writer [a w opts] (pr-atom a w opts "RAtom" {:val (-deref a)}))
 
   IWatchable
   (-notify-watches [this old new] (notify-w this old new))
@@ -232,7 +232,8 @@
   (-hash [_] (hash [f args]))
 
   IPrintWithWriter
-  (-pr-writer [a w opts] (pr-atom a w opts "Track:")))
+  (-pr-writer [a w opts] (pr-atom a w opts "Track" {:val (-deref a)
+                                                    :f f})))
 
 (defn make-track [f args]
   (Track. f args nil))
@@ -306,7 +307,8 @@
   (-swap! [a f x y more] (-reset! a (apply f (._peek a) x y more)))
 
   IPrintWithWriter
-  (-pr-writer [a w opts] (pr-atom a w opts (str "Cursor: " path)))
+  (-pr-writer [a w opts] (pr-atom a w opts "RCursor" {:val (-deref a)
+                                                      :path path}))
 
   IWatchable
   (-notify-watches [this old new] (notify-w this old new))
@@ -506,7 +508,7 @@
   (-equiv [o other] (identical? o other))
 
   IPrintWithWriter
-  (-pr-writer [a w opts] (pr-atom a w opts (str "Reaction " (hash a) ":")))
+  (-pr-writer [a w opts] (pr-atom a w opts "Reaction" {:val (-deref a)}))
 
   IHash
   (-hash [this] (goog/getUid this)))
@@ -596,7 +598,7 @@
   (-remove-watch [this key]       (remove-w this key))
 
   IPrintWithWriter
-  (-pr-writer [a w opts] (pr-atom a w opts "Wrap:")))
+  (-pr-writer [a w opts] (pr-atom a w opts "Wrapper" {:val (-deref a)})))
 
 (defn make-wrapper [value callback-fn args]
   (->Wrapper value

test/reagenttest/testratom.cljs

@@ -1,7 +1,7 @@
 (ns reagenttest.testratom
   (:require [clojure.test :as t :refer-macros [is deftest testing]]
             [reagent.ratom :as rv :refer-macros [run! reaction]]
-            [reagent.debug :as debug :refer-macros [dbg]]
+            [reagent.debug :as debug :refer-macros [dbg dev?]]
             [reagent.core :as r]))
 
 (defn fixture [f]
@@ -468,3 +468,18 @@
         state (with-meta (r/atom value) meta-value)]
     (is (= (meta state) meta-value))
     (is (= @state value))))
+
+(deftest print-ratom-test
+  (let [x (r/atom {:foo 1})]
+    (is (= "#object[reagent.ratom.RAtom {:val {:foo 1}}]"
+           (pr-str x)))
+    (is (= "#object[reagent.ratom.RCursor {:val 1, :path [:foo]}]"
+           (pr-str (r/cursor x [:foo]))))
+    (is (= "#object[reagent.ratom.Wrapper {:val 1}]"
+           (pr-str (r/wrap (:foo @x) #(reset! x %)))))
+    (is (= (if (dev?)
+             "#object[reagent.ratom.Track {:val 1, :f #object[reagenttest$testratom$foo]}]"
+             "#object[reagent.ratom.Track {:val 1, :f #object[Function]}]")
+           (pr-str (r/track (fn foo [] (:foo @x))))))
+    (is (= "#object[reagent.ratom.Reaction {:val 1}]"
+           (pr-str (reaction (:foo @x)))))))

test/reagenttest/testreagent.cljs

@@ -1124,7 +1124,7 @@
 (deftest test-object-children
   (is (= "<p>foo bar1</p>"
          (rstr [:p 'foo " " :bar nil 1])))
-  (is (= "<p>#&lt;Atom: 1&gt;</p>"
+  (is (= "<p>#object[reagent.ratom.RAtom {:val 1}]</p>"
          (rstr [:p (r/atom 1)]))))
 
 (deftest test-after-render