How can I wrap a string in an input-stream in such a way that I can test the function bellow?
(defn parse-body [body]
(cheshire/parse-stream (clojure.java.io/reader body) true))
(deftest test-parse-body
(testing "read body"
(let [body "{\"age\": 28}"] ;; must wrap string
(is (= (parse-body body) {:age 28}))
)))
It is straightforward to construct an InputStream from a String using host interop, by converting to a byte-array first:
(defn string->stream
([s] (string->stream s "UTF-8"))
([s encoding]
(-> s
(.getBytes encoding)
(java.io.ByteArrayInputStream.))))
As another stream and byte interop example, here's a function that returns a vector of the bytes produced when encoding a String to a given format:
(defn show-bytes
[s encoding]
(let [buf (java.io.ByteArrayOutputStream.)
stream (string->stream s encoding)
;; worst case, 8 bytes per char?
data (byte-array (* (count s) 8))
size (.read stream data 0 (count data))]
(.write buf data 0 size)
(.flush buf)
(apply vector-of :byte (.toByteArray buf))))
+user=> (string->stream "hello")
#object[java.io.ByteArrayInputStream 0x39b43d60 "java.io.ByteArrayInputStream@39b43d60"]
+user=> (isa? (class *1) java.io.InputStream)
true
+user=> (show-bytes "hello" "UTF-8")
[104 101 108 108 111]
+user=> (show-bytes "hello" "UTF-32")
[0 0 0 104 0 0 0 101 0 0 0 108 0 0 0 108 0 0 0 111]
clojure.java.io/readeraccepts any (char-based)java.io.Reader, and so the detour to (byte-based)java.io.InputStreamand character encoding is unnecessary. Instead, simply wrap the string in ajava.io.StringReader:(java.io.StringReader. body).