read HTTP messages with a content-length

smol-http/http-msg.rkt

@@ -179,8 +179,25 @@
       #:break (string=? hln "")
       (or (string->header-kv hln)
           (raise-read-http-error "read-http-msg: invalid header line: ~s" hln))))
-  ;; TODO: response body; the reader should be determined by the headers
-  (make-msg sln hdrs))
+  (define msg (make-msg sln hdrs))
+  (define bdy (read-http-body (hash-ref (http-msg-headers msg) 'transfer-encoding #f)
+                              (hash-ref (http-msg-headers msg) 'content-length #f)
+                              port))
+  (http-set-body msg bdy))
+
+;; (http-body-reader tenc clen [port]) -> http-body?
+;; tenc, clen : (or/c #f bytes?)
+;; port : input-port?
+(define (read-http-body tenc clen [port (current-input-port)])
+  (define len (and clen (string->number (bytes->string/utf-8 clen))))
+  (cond
+    [(equal? tenc #"chunked") (read-chunked-stream port)]
+    [(number? len) (read-bytes len port)]
+    [(and (not tenc) (not len)) #f]
+    [else (raise-read-http-error "read-http-body: not sure how to read HTTP body")]))
+
+(define (read-chunked-stream port)
+  ('...))
 
 ;; ==========================================
 
@@ -197,8 +214,12 @@
 
   (check-bytes->http-msg #"HTTP/1.1 200 OK\r\n"
                          #"Content-Type: text/html\r\n"
+                         #"Content-Length: 5\r\n"
                          #"\r\n"
-                         (make-http-res 200 '([content-type . "text/html"])))
+                         #"hello"
+                         (http-set-body (make-http-res 200 '([content-type . "text/html"]
+                                                             [content-length . 5]))
+                                        #"hello"))
 
   ;; "write --> read" works
   (let-values ([(in out) (make-pipe)])