[#1004] XML edn reading and populating *data-readers* for feature deps (#1012)

* add XML edn reading and make *data-readers* closer to Clojure

- initial value of *data-readers*: empty map
- add XML readers to feature-flagged edn-readers for parsing *input*
- add edn-readers to *data-readers* to emulate data_readers.clj handling

* add YAML round-trip testing

* set root val of *data-readers* at top level

src/babashka/impl/clojure/core.clj

@@ -26,7 +26,7 @@
   ([sym] (core-dynamic-var sym nil))
   ([sym init-val] (sci/new-dynamic-var sym init-val {:ns clojure-core-ns})))
 
-(def data-readers (core-dynamic-var '*data-readers*))
+(def data-readers (core-dynamic-var '*data-readers* {}))
 (def command-line-args (core-dynamic-var '*command-line-args*))
 (def warn-on-reflection (core-dynamic-var '*warn-on-reflection* false))
 (def math-context (core-dynamic-var '*math-context*))

src/babashka/main.clj

@@ -425,7 +425,13 @@ Use bb run --help to show this help output.
 
 (def edn-readers (cond-> {}
                    features/yaml?
-                   (assoc 'ordered/map @(resolve 'flatland.ordered.map/ordered-map))))
+                   (assoc 'ordered/map @(resolve 'flatland.ordered.map/ordered-map))
+                   features/xml?
+                   (assoc 'xml/ns @(resolve 'clojure.data.xml.name/uri-symbol)
+                          'xml/element @(resolve 'clojure.data.xml.node/tagged-element))))
+
+;; also put the edn readers into *data-readers*
+(sci/alter-var-root core/data-readers into edn-readers)
 
 (defn edn-seq*
   [^java.io.BufferedReader rdr]

test/babashka/xml_test.clj

@@ -0,0 +1,17 @@
+(ns babashka.xml-test
+  (:require [babashka.test-utils :as test-utils]
+            [clojure.string :as str]
+            [clojure.test :refer [deftest is testing]]))
+
+(def simple-xml-str "<a><b>data</b></a>")
+
+(deftest xml-edn-read-test
+  (let [parsed-edn     (test-utils/bb nil (str "(xml/parse-str \"" simple-xml-str "\")"))
+        emitted-xml    (test-utils/bb parsed-edn "(xml/emit-str *input*)")]
+    (is (str/includes? emitted-xml simple-xml-str))))
+
+(def round-trip-prog
+  (str "(xml/emit-str (read-string (pr-str (xml/parse-str \"" simple-xml-str "\"))))"))
+
+(deftest xml-data-readers-test
+  (is (str/includes? (test-utils/bb nil round-trip-prog) simple-xml-str)))

test/babashka/yaml_test.clj

@@ -0,0 +1,18 @@
+(ns babashka.yaml-test
+  (:require [babashka.test-utils :as test-utils]
+            [clojure.string :as str]
+            [clojure.test :refer [deftest is testing]]))
+
+(def simple-yaml-str "topic: [point 1, point 2]")
+
+(deftest yaml-edn-read-test
+  (let [parsed-edn   (test-utils/bb nil (str "(yaml/parse-string \"" simple-yaml-str "\")"))
+        emitted-yaml (test-utils/bb parsed-edn "(yaml/generate-string *input*)")]
+    (is (every? #(str/includes? emitted-yaml %) ["topic:" "point 1" "point 2"]))))
+
+(def round-trip-prog
+  (str "(yaml/generate-string (read-string (pr-str (yaml/parse-string \"" simple-yaml-str "\"))))"))
+
+(deftest yaml-data-readers-test
+  (let [emitted-yaml (test-utils/bb nil round-trip-prog)]
+    (is (every? #(str/includes? emitted-yaml %) ["topic:" "point 1" "point 2"]))))