Add support for default transit handler #36

src/babashka/pods.clj

@@ -15,8 +15,11 @@
   ([pod-id-or-pod sym args] (invoke pod-id-or-pod sym args {}))
   ([pod-id-or-pod sym args opts] (jvm/invoke pod-id-or-pod sym args opts)))
 
-(defn add-transit-read-handler [tag fn]
+(defn add-transit-read-handler! [tag fn]
-  (jvm/add-transit-read-handler tag fn))
+  (jvm/add-transit-read-handler! tag fn))
 
-(defn add-transit-write-handler [tag fn classes]
+(defn add-transit-write-handler! [tag fn classes]
-  (jvm/add-transit-write-handler tag fn classes))
+  (jvm/add-transit-write-handler! tag fn classes))
+
+(defn set-transit-default-write-handler! [tag-fn val-fn]
+  (jvm/set-transit-default-write-handler! tag-fn val-fn))

src/babashka/pods/impl.clj

@@ -54,11 +54,12 @@
       (transit/read r))))
 
 ;; https://www.cognitect.com/blog/2015/9/10/extending-transit
-(defn add-transit-read-handler [tag fn]
+(defn add-transit-read-handler!
-  (let [rh (transit/read-handler fn)]
+  ([tag fn]
-    (swap! transit-read-handlers assoc-in [*pod-id* tag] rh)
+   (let [rh (transit/read-handler fn)]
-    (update-transit-read-handler-map)
+     (swap! transit-read-handlers assoc-in [*pod-id* tag] rh)
-    nil))
+     (update-transit-read-handler-map)
+     nil)))
 
 (defonce transit-write-handlers (atom {}))
 (defonce transit-write-handler-maps (atom {}))
@@ -68,16 +69,23 @@
          (transit/write-handler-map (get @transit-write-handlers *pod-id*))))
 
 ;; https://www.cognitect.com/blog/2015/9/10/extending-transit
-(defn add-transit-write-handler [tag fn classes]
+(defn add-transit-write-handler! [tag fn classes]
   (let [rh (transit/write-handler tag fn)]
     (doseq [class classes]
       (swap! transit-write-handlers assoc-in [*pod-id* class] rh)))
   (update-transit-write-handler-map)
   nil)
 
+(defonce transit-default-write-handlers (atom {}))
+
+(defn set-transit-default-write-handler! [tag-fn val-fn]
+  (let [wh (transit/write-handler tag-fn val-fn)]
+    (swap! transit-default-write-handlers assoc *pod-id* wh)))
+
 (defn transit-json-write [pod-id ^String s]
   (with-open [baos (java.io.ByteArrayOutputStream. 4096)]
-    (let [w (transit/writer baos :json {:handlers (get @transit-write-handler-maps pod-id)})]
+    (let [w (transit/writer baos :json {:handlers (get @transit-write-handler-maps pod-id)
+                                        :default-handler (get @transit-default-write-handlers pod-id)})]
       (transit/write w s)
       (str baos))))
 

src/babashka/pods/jvm.clj

@@ -71,8 +71,11 @@
   ([pod-id sym args] (invoke pod-id sym args {}))
   ([pod-id sym args opts] (impl/invoke-public pod-id sym args opts)))
 
-(defn add-transit-read-handler [tag fn]
+(defn add-transit-read-handler! [tag fn]
-  (impl/add-transit-read-handler tag fn))
+  (impl/add-transit-read-handler! tag fn))
 
-(defn add-transit-write-handler [tag fn classes]
+(defn add-transit-write-handler! [tag fn classes]
-  (impl/add-transit-write-handler tag fn classes))
+  (impl/add-transit-write-handler! tag fn classes))
+
+(defn set-transit-default-write-handler! [tag-fn val-fn]
+  (impl/set-transit-default-write-handler! tag-fn val-fn))

src/babashka/pods/sci.clj

@@ -81,8 +81,11 @@
   ([pod-id sym args] (invoke pod-id sym args {}))
   ([pod-id sym args opts] (impl/invoke-public pod-id sym args opts)))
 
-(defn add-transit-read-handler [tag fn]
+(defn add-transit-read-handler! [tag fn]
-  (impl/add-transit-read-handler tag fn))
+  (impl/add-transit-read-handler! tag fn))
 
-(defn add-transit-write-handler [tag fn classes]
+(defn add-transit-write-handler! [tag fn classes]
-  (impl/add-transit-write-handler tag fn classes))
+  (impl/add-transit-write-handler! tag fn classes))
+
+(defn set-transit-default-write-handler! [tag-fn val-fn]
+  (impl/set-transit-default-write-handler! tag-fn val-fn))

test-pod/pod/test_pod.clj

@@ -40,7 +40,11 @@
                                         {"local-date-time"
                                          (transit/read-handler
                                           (fn [s]
-                                            (java.time.LocalDateTime/parse s)))}})]
+                                            (java.time.LocalDateTime/parse s)))
+                                         "java.array"
+                                         (transit/read-handler
+                                          (fn [v]
+                                            (into-array v)))}})]
       (transit/read r))))
 
 (defn transit-json-write [s]
@@ -49,7 +53,11 @@
                                         {java.time.LocalDateTime
                                          (transit/write-handler
                                           "local-date-time"
-                                          str)}})]
+                                          str)}
+                                        :default-handler
+                                        (transit/write-handler
+                                         (fn [x] (when (.isArray (class x)) "java.array"))
+                                         vec)})]
       (transit/write w s)
       (str baos))))
 
@@ -121,14 +129,26 @@
                                                 {"name" "read-other-tag"
                                                  "code" "(defn read-other-tag [x] [x x])"}
                                                 {"name" "-local-date-time"}
-                                                {"name" "local-date-time"
+                                                {"name" "transit-stuff"
                                                  "code" "
-(babashka.pods/add-transit-read-handler \"local-date-time\"
+(babashka.pods/add-transit-read-handler! \"local-date-time\"
   (fn [s] (java.time.LocalDateTime/parse s)))
-(babashka.pods/add-transit-write-handler \"local-date-time\"
+
+(babashka.pods/add-transit-write-handler! \"local-date-time\"
   str #{java.time.LocalDateTime})
+
 (defn local-date-time [x]
-  (-local-date-time x))"}]
+  (-local-date-time x))
+
+;; serialize Java arrays as vectors with tag java.array
+(babashka.pods/set-transit-default-write-handler!
+  (fn [x] (when (.isArray (class x)) \"java.array\"))
+  vec)
+
+(babashka.pods/add-transit-read-handler! \"java.array\"
+  into-array)
+
+"}]
                                                dependents)}
                                  {"name" "pod.test-pod.loaded"
                                   "defer" "true"}

test-resources/test_program.clj

@@ -74,6 +74,12 @@
     (instance? java.time.LocalDateTime (pod.test-pod/local-date-time (java.time.LocalDateTime/now)))
     true))
 
+(def assoc-string-array
+  (if (= "transit+json" fmt)
+    (let [v (:a (pod.test-pod/assoc {} :a (into-array String ["foo"])))]
+      (.isArray (class v)))
+    true))
+
 (require '[pod.test-pod.only-code :as only-code])
 (def should-be-1 (only-code/foo))
 
@@ -101,4 +107,5 @@
  loaded
  fn-called
  local-date-time
+ assoc-string-array
  should-be-1]

test/babashka/pods/sci_test.clj

@@ -14,10 +14,12 @@
                                                  (apply pods/load-pod @ctx-ref args))
                                      'invoke pods/invoke
                                      'unload-pod pods/unload-pod
-                                     'add-transit-read-handler  pods/add-transit-read-handler
+                                     'add-transit-read-handler!  pods/add-transit-read-handler!
-                                     'add-transit-write-handler pods/add-transit-write-handler}}
+                                     'add-transit-write-handler! pods/add-transit-write-handler!
+                                     'set-transit-default-write-handler! pods/set-transit-default-write-handler!}}
                        :classes {'System System
-                                 'java.time.LocalDateTime java.time.LocalDateTime}})
+                                 'java.time.LocalDateTime java.time.LocalDateTime
+                                 'java.lang.Class Class}})
         _ (vreset! ctx-ref ctx)
         ret (sci/binding [sci/out out
                           sci/err err]

test/babashka/pods/test_common.clj

@@ -26,7 +26,8 @@
                         [[1] [1]]
                         2
                         3
-                        true
+                        true ;; local-date
+                        true ;; roundtrip string array
                         1]
                (concat ret (repeat ::nil)))]
     (if (instance? java.util.regex.Pattern expected)