dream: query/header convenience helpers + content negotiation + 18 tests

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

lib/dream/tests/types.sx

@@ -1,4 +1,4 @@
-;; lib/dream/tests/types.sx — request/response/route records.
+;; lib/dream/tests/types.sx — request/response/route records + convenience.
 
 (define dream-ty-pass 0)
 (define dream-ty-fail 0)
@@ -66,6 +66,57 @@
 (dream-ty-test "with-params a" (dream-param dream-ty-req3 "a") "1")
 (dream-ty-test "with-params b" (dream-param dream-ty-req3 "b") "2")
 
+;; ── request convenience ────────────────────────────────────────────
+(dream-ty-test "queries dict" (dream-queries dream-ty-req) {:x "1" :tab "info"})
+(dream-ty-test
+  "query-or present"
+  (dream-query-param-or dream-ty-req "tab" "def")
+  "info")
+(dream-ty-test
+  "query-or default"
+  (dream-query-param-or dream-ty-req "missing" "def")
+  "def")
+(dream-ty-test "has-query yes" (dream-has-query? dream-ty-req "tab") true)
+(dream-ty-test "has-query no" (dream-has-query? dream-ty-req "nope") false)
+(dream-ty-test
+  "header-or present"
+  (dream-header-or dream-ty-req "x-token" "d")
+  "abc")
+(dream-ty-test
+  "header-or default"
+  (dream-header-or dream-ty-req "x-absent" "d")
+  "d")
+(dream-ty-test
+  "has-header yes"
+  (dream-has-header? dream-ty-req "Content-Type")
+  true)
+(dream-ty-test
+  "has-header no"
+  (dream-has-header? dream-ty-req "x-absent")
+  false)
+(dream-ty-test "param-or default" (dream-param-or dream-ty-req "id" "0") "0")
+(dream-ty-test
+  "param-or present"
+  (dream-param-or dream-ty-req2 "id" "0")
+  "42")
+(dream-ty-test
+  "content-type-of"
+  (dream-content-type-of dream-ty-req)
+  "text/html")
+(dream-ty-test "method-is yes" (dream-method-is? dream-ty-req "get") true)
+(dream-ty-test "method-is no" (dream-method-is? dream-ty-req "post") false)
+(define dream-ty-jreq (dream-request "GET" "/" {:Accept "application/json, text/html"} ""))
+(dream-ty-test
+  "accepts json"
+  (dream-accepts? dream-ty-jreq "application/json")
+  true)
+(dream-ty-test
+  "accepts missing"
+  (dream-accepts? dream-ty-req "application/json")
+  false)
+(dream-ty-test "wants-json yes" (dream-wants-json? dream-ty-jreq) true)
+(dream-ty-test "wants-json no" (dream-wants-json? dream-ty-req) false)
+
 ;; ── response construction ──────────────────────────────────────────
 (dream-ty-test "html status" (dream-status (dream-html "<p>")) 200)
 (dream-ty-test "html body" (dream-resp-body (dream-html "<p>")) "<p>")

lib/dream/types.sx

@@ -93,6 +93,35 @@
         (keys more)))))
 (define dream-set-body (fn (req body) (assoc req :body body)))
 
+;; ── request convenience ────────────────────────────────────────────
+(define dream-queries (fn (req) (get req :query)))
+(define
+  dream-query-param-or
+  (fn (req name default) (or (dream-query-param req name) default)))
+(define dream-has-query? (fn (req name) (has-key? (get req :query) name)))
+(define
+  dream-header-or
+  (fn (req name default) (or (dream-header req name) default)))
+(define
+  dream-has-header?
+  (fn (req name) (has-key? (get req :headers) (lower name))))
+(define
+  dream-param-or
+  (fn (req name default) (or (dream-param req name) default)))
+(define dream-has-param? (fn (req name) (has-key? (get req :params) name)))
+(define dream-content-type-of (fn (req) (dream-header req "content-type")))
+(define dream-method-is? (fn (req m) (= (dream-method req) (upper m))))
+(define
+  dream-accepts?
+  (fn
+    (req mime)
+    (let
+      ((a (dream-header req "accept")))
+      (if a (contains? a mime) false))))
+(define
+  dream-wants-json?
+  (fn (req) (dream-accepts? req "application/json")))
+
 ;; ── response ───────────────────────────────────────────────────────
 (define dream-response (fn (status headers body) {:body body :headers (dr/normalize-headers headers) :status status}))
 

plans/dream-on-sx.md

@@ -119,6 +119,11 @@ with extensions + hardening below.
   wrong-secret cookie yields a fresh session instead of a hijack. `dream-cookie-sign` /
   `dream-cookie-unsign` (keyed hash; same not-cryptographic caveat — inject a host HMAC
   in production). Plain `dream-sessions` unchanged for the no-secret case.
+- **2026-06-07 — Ext: query/header convenience** (`lib/dream/types.sx`, types suite
+  41→59, 358 total). `dream-queries`, `dream-query-param-or` / `dream-header-or` /
+  `dream-param-or` (defaults), `dream-has-query?` / `-header?` / `-param?`,
+  `dream-content-type-of`, `dream-method-is?`, `dream-accepts?` / `dream-wants-json?`
+  (Accept-header content negotiation).
 
 ## Extensions (post-roadmap)
 
@@ -131,7 +136,7 @@ The five-types core is complete; these harden it toward a production HTTP front
 - [x] **Error-handling middleware** (`dream-catch` / custom 500 templates; `guard`-based).
 - [x] **Signed session cookies** (`dream-sessions-signed` — tamper-evident sid).
 - [x] **JSON helpers** (encode + recursive-descent parse, pure SX).
-- [ ] **Query/header convenience** (`dream-queries`, defaults).
+- [x] **Query/header convenience** (`dream-queries`, `*-or` defaults, `dream-accepts?`).
 - [ ] **`api.sx` facade + README** — single load point listing the public surface.
 
 ## Stdlib additions Dream will need