dream: static file serving — mime, etags, 304, ranges, traversal guard + 28 tests

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/dream/tests/static.sx

@@ -0,0 +1,125 @@
+;; lib/dream/tests/static.sx — content types, etags, 304, ranges, traversal.
+
+(define dream-st-pass 0)
+(define dream-st-fail 0)
+(define dream-st-fails (list))
+
+(define
+  dream-st-test
+  (fn
+    (name actual expected)
+    (if
+      (= actual expected)
+      (set! dream-st-pass (+ dream-st-pass 1))
+      (begin
+        (set! dream-st-fail (+ dream-st-fail 1))
+        (append! dream-st-fails {:name name :actual actual :expected expected})))))
+
+;; ── content type + ext ─────────────────────────────────────────────
+(dream-st-test "ext css" (dr/ext-of "a/b/style.css") "css")
+(dream-st-test "ext multi-dot" (dr/ext-of "a.min.js") "js")
+(dream-st-test "ext none" (dr/ext-of "README") "")
+(dream-st-test
+  "ctype css"
+  (dream-content-type-for "x.css")
+  "text/css; charset=utf-8")
+(dream-st-test
+  "ctype html"
+  (dream-content-type-for "x.html")
+  "text/html; charset=utf-8")
+(dream-st-test "ctype png" (dream-content-type-for "x.png") "image/png")
+(dream-st-test
+  "ctype unknown"
+  (dream-content-type-for "x.bin")
+  "application/octet-stream")
+
+;; ── etag ───────────────────────────────────────────────────────────
+(dream-st-test
+  "etag deterministic"
+  (= (dr/etag-of "abc") (dr/etag-of "abc"))
+  true)
+(dream-st-test
+  "etag content-sensitive"
+  (= (dr/etag-of "abc") (dr/etag-of "abd"))
+  false)
+(dream-st-test
+  "etag length-sensitive"
+  (= (dr/etag-of "ab") (dr/etag-of "abc"))
+  false)
+
+;; ── serving via router mount ───────────────────────────────────────
+(define dream-st-files {:/srv/app.css "body{color:red}" :/srv/index.html "<h1>Hi</h1>"})
+(define dream-st-fs (dream-memory-fs dream-st-files))
+(define
+  dream-st-app
+  (dream-router
+    (list (dream-get "/static/**" (dream-static-with "/srv" dream-st-fs)))))
+(define
+  dream-st-get
+  (fn
+    (target headers)
+    (dream-st-app (dream-request "GET" target headers ""))))
+
+(define dream-st-css (dream-st-get "/static/app.css" {}))
+(dream-st-test "serve status 200" (dream-status dream-st-css) 200)
+(dream-st-test "serve body" (dream-resp-body dream-st-css) "body{color:red}")
+(dream-st-test
+  "serve content-type"
+  (dream-resp-header dream-st-css "content-type")
+  "text/css; charset=utf-8")
+(dream-st-test
+  "serve accept-ranges"
+  (dream-resp-header dream-st-css "accept-ranges")
+  "bytes")
+(dream-st-test
+  "serve has etag"
+  (not (nil? (dream-resp-header dream-st-css "etag")))
+  true)
+(dream-st-test
+  "missing file 404"
+  (dream-status (dream-st-get "/static/nope.txt" {}))
+  404)
+(dream-st-test
+  "traversal blocked 403"
+  (dream-status (dream-st-get "/static/../secret" {}))
+  403)
+
+;; ── conditional: If-None-Match -> 304 ──────────────────────────────
+(define dream-st-etag (dream-resp-header dream-st-css "etag"))
+(define dream-st-304 (dream-st-get "/static/app.css" {:If-None-Match dream-st-etag}))
+(dream-st-test "matching etag 304" (dream-status dream-st-304) 304)
+(dream-st-test "304 empty body" (dream-resp-body dream-st-304) "")
+(dream-st-test
+  "stale etag 200"
+  (dream-status (dream-st-get "/static/app.css" {:If-None-Match "\"stale\""}))
+  200)
+(dream-st-test
+  "star etag 304"
+  (dream-status (dream-st-get "/static/app.css" {:If-None-Match "*"}))
+  304)
+
+;; ── range requests ─────────────────────────────────────────────────
+(define dream-st-range (dream-st-get "/static/app.css" {:Range "bytes=0-3"}))
+(dream-st-test "range status 206" (dream-status dream-st-range) 206)
+(dream-st-test "range body slice" (dream-resp-body dream-st-range) "body")
+(dream-st-test
+  "range content-range"
+  (dream-resp-header dream-st-range "content-range")
+  "bytes 0-3/15")
+(define dream-st-open (dream-st-get "/static/app.css" {:Range "bytes=5-"}))
+(dream-st-test "open range body" (dream-resp-body dream-st-open) "color:red}")
+(dream-st-test
+  "open range header"
+  (dream-resp-header dream-st-open "content-range")
+  "bytes 5-14/15")
+(define dream-st-bad (dream-st-get "/static/app.css" {:Range "bytes=20-30"}))
+(dream-st-test
+  "unsatisfiable range 416"
+  (dream-status dream-st-bad)
+  416)
+(dream-st-test
+  "416 content-range"
+  (dream-resp-header dream-st-bad "content-range")
+  "bytes */15")
+
+(define dream-st-tests-run! (fn () {:total (+ dream-st-pass dream-st-fail) :passed dream-st-pass :failed dream-st-fail :fails dream-st-fails}))