Make more web server encoding tweaks

tests/web-server.scm

@@ -81,6 +81,34 @@
         "☺"
         body)))))
 
+(run-fibers-for-tests
+ (lambda ()
+   (let* ((web-server
+           (run-knots-web-server
+            (lambda (request)
+              (values '((content-type . (text/plain
+                                         (charset . "utf-8")))
+                        (content-length . 3))
+                      (lambda (port)
+                        (display "☺" port))))
+            #:port 0)) ;; Bind to any port
+          (port
+           (web-server-port web-server))
+          (uri
+           (build-uri 'http #:host "127.0.0.1" #:port port)))
+
+     (let ((response
+            body
+            (http-get
+             uri
+             ;; TODO Remove once using Guile 3.0.10
+             #:streaming? #t
+             #:port (non-blocking-open-socket-for-uri uri))))
+       (assert-equal
+        "☺"
+        (utf8->string
+         (get-bytevector-n body 3)))))))
+
 ;; Test hanlding of exceptions when writing the response to a client
 (run-fibers-for-tests
  (lambda ()