From 70a58bddd84a81acb0245a2bcfb98b8b0ff0e498 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Tue, 24 Mar 2026 01:29:59 +0000
Subject: [PATCH] =?UTF-8?q?Exhaustive=20HTML=20render=20tests=20=E2=80=94?=
 =?UTF-8?q?=20143=20tests=20for=20adapter-html.sx?=
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spec/tests/test-render-html.sx covers the full HTML serialization surface:
  text/literals, content escaping, attribute escaping, normal elements,
  all 14 void elements, 18 boolean attributes, regular/data-*/aria-* attrs,
  fragments, raw HTML, headings, lists, tables, forms, media, semantic
  elements, SVG, control flow (if/when/cond), let bindings, map/for-each,
  components (simple/children/keyword+children/nested), macros, begin/do,
  letrec, scope/provide, islands with hydration markers, lakes, marshes,
  threading, define-in-template.

Validates adapter-html.sx can replace sx_render.ml as the canonical renderer.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 spec/tests/test-render-html.sx | 763 +++++++++++++++++++++++++++++++++
 1 file changed, 763 insertions(+)
 create mode 100644 spec/tests/test-render-html.sx

diff --git a/spec/tests/test-render-html.sx b/spec/tests/test-render-html.sx
new file mode 100644
index 0000000..691e29b
--- /dev/null
+++ b/spec/tests/test-render-html.sx
@@ -0,0 +1,763 @@
+;; ==========================================================================
+;; test-render-html.sx — Exhaustive tests for HTML rendering
+;;
+;; Tests render-to-html against the HTML serialization specification.
+;; Every test verifies the SX renderer produces correct HTML strings.
+;;
+;; Requires: test-framework.sx, adapter-html.sx loaded.
+;; ==========================================================================
+
+
+;; Helper: render a QUOTED SX expression to HTML string.
+;; The expression is first evaluated in the env (to resolve symbols),
+;; then the result is passed to render-to-html.
+;; For simple values (strings, numbers), use rh-val instead.
+(define rh
+  (fn (expr)
+    (let ((env (env-extend (test-env))))
+      (render-to-html expr env))))
+
+;; Helper: render a literal value (no evaluation needed).
+;; Uses render-value-to-html which skips the eval-expr dispatch.
+(define rh-val
+  (fn (val)
+    (render-value-to-html val (env-extend (test-env)))))
+
+;; Helper: render with a pre-built env
+(define rh-env
+  (fn (expr env)
+    (render-to-html expr env)))
+
+
+;; --------------------------------------------------------------------------
+;; 1. Text content and literals
+;; --------------------------------------------------------------------------
+
+(defsuite "html-text"
+  (deftest "string renders as escaped text"
+    (assert-equal "hello" (rh-val "hello")))
+
+  (deftest "number renders as string"
+    (assert-equal "42" (rh-val 42)))
+
+  (deftest "float renders as string"
+    (assert-equal "3.14" (rh-val 3.14)))
+
+  (deftest "boolean true renders as text"
+    (assert-equal "true" (rh-val true)))
+
+  (deftest "boolean false renders as text"
+    (assert-equal "false" (rh-val false)))
+
+  (deftest "nil renders as empty string"
+    (assert-equal "" (rh-val nil)))
+
+  (deftest "keyword renders as text"
+    (assert-equal "hello" (rh-val :hello))))
+
+
+;; --------------------------------------------------------------------------
+;; 2. HTML escaping — content
+;; --------------------------------------------------------------------------
+
+(defsuite "html-escaping-content"
+  (deftest "ampersand escaped in text"
+    (assert-equal "a &amp; b" (rh-val "a & b")))
+
+  (deftest "less-than escaped in text"
+    (assert-equal "a &lt; b" (rh-val "a < b")))
+
+  (deftest "greater-than escaped in text"
+    (assert-equal "a &gt; b" (rh-val "a > b")))
+
+  (deftest "multiple special chars escaped"
+    (assert-equal "&lt;b&gt;tag&lt;/b&gt;"
+      (rh-val "<b>tag</b>")))
+
+  (deftest "text inside element is escaped"
+    (assert-equal "<p>a &amp; b</p>"
+      (rh '(p "a & b")))))
+
+
+;; --------------------------------------------------------------------------
+;; 3. HTML escaping — attributes
+;; --------------------------------------------------------------------------
+
+(defsuite "html-escaping-attrs"
+  (deftest "ampersand escaped in attribute value"
+    (assert-equal "<div title=\"a &amp; b\"></div>"
+      (rh '(div :title "a & b"))))
+
+  (deftest "angle brackets escaped in attribute value"
+    (assert-equal "<div title=\"&lt;b&gt;\"></div>"
+      (rh '(div :title "<b>")))))
+
+
+;; --------------------------------------------------------------------------
+;; 4. Normal elements — open tag, children, close tag
+;; --------------------------------------------------------------------------
+
+(defsuite "html-normal-elements"
+  (deftest "div with text"
+    (assert-equal "<div>hello</div>" (rh '(div "hello"))))
+
+  (deftest "p with text"
+    (assert-equal "<p>paragraph</p>" (rh '(p "paragraph"))))
+
+  (deftest "span with text"
+    (assert-equal "<span>inline</span>" (rh '(span "inline"))))
+
+  (deftest "empty div"
+    (assert-equal "<div></div>" (rh '(div))))
+
+  (deftest "nested elements"
+    (assert-equal "<div><p>inner</p></div>"
+      (rh '(div (p "inner")))))
+
+  (deftest "multiple children"
+    (assert-equal "<div><p>a</p><p>b</p></div>"
+      (rh '(div (p "a") (p "b")))))
+
+  (deftest "deep nesting"
+    (assert-equal "<div><section><article><p>deep</p></article></section></div>"
+      (rh '(div (section (article (p "deep")))))))
+
+  (deftest "mixed text and element children"
+    (assert-equal "<p>hello <strong>world</strong></p>"
+      (rh '(p "hello " (strong "world"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 5. Void elements — self-closing, no children
+;; --------------------------------------------------------------------------
+
+(defsuite "html-void-elements"
+  (deftest "br"
+    (assert-equal "<br />" (rh '(br))))
+
+  (deftest "hr"
+    (assert-equal "<hr />" (rh '(hr))))
+
+  (deftest "img with src"
+    (assert-equal "<img src=\"photo.jpg\" />"
+      (rh '(img :src "photo.jpg"))))
+
+  (deftest "input with type"
+    (assert-equal "<input type=\"text\" />"
+      (rh '(input :type "text"))))
+
+  (deftest "meta with charset"
+    (assert-equal "<meta charset=\"utf-8\" />"
+      (rh '(meta :charset "utf-8"))))
+
+  (deftest "link with rel and href"
+    (assert-equal "<link rel=\"stylesheet\" href=\"style.css\" />"
+      (rh '(link :rel "stylesheet" :href "style.css"))))
+
+  (deftest "source with src"
+    (assert-equal "<source src=\"video.mp4\" />"
+      (rh '(source :src "video.mp4"))))
+
+  (deftest "col"
+    (assert-equal "<col />" (rh '(col))))
+
+  (deftest "wbr"
+    (assert-equal "<wbr />" (rh '(wbr)))))
+
+
+;; --------------------------------------------------------------------------
+;; 6. Boolean attributes — name only when truthy
+;; --------------------------------------------------------------------------
+
+(defsuite "html-boolean-attrs"
+  (deftest "checked true"
+    (assert-equal "<input checked />"
+      (rh '(input :checked true))))
+
+  (deftest "checked false omitted"
+    (assert-equal "<input />"
+      (rh '(input :checked false))))
+
+  (deftest "disabled true"
+    (assert-equal "<button disabled>click</button>"
+      (rh '(button :disabled true "click"))))
+
+  (deftest "disabled false omitted"
+    (assert-equal "<button>click</button>"
+      (rh '(button :disabled false "click"))))
+
+  (deftest "readonly"
+    (assert-equal "<input readonly />"
+      (rh '(input :readonly true))))
+
+  (deftest "required"
+    (assert-equal "<input required />"
+      (rh '(input :required true))))
+
+  (deftest "multiple"
+    (assert-equal "<select multiple></select>"
+      (rh '(select :multiple true))))
+
+  (deftest "hidden"
+    (assert-equal "<div hidden></div>"
+      (rh '(div :hidden true))))
+
+  (deftest "autofocus"
+    (assert-equal "<input autofocus />"
+      (rh '(input :autofocus true))))
+
+  (deftest "autoplay"
+    (assert-equal "<video autoplay></video>"
+      (rh '(video :autoplay true))))
+
+  (deftest "loop"
+    (assert-equal "<video loop></video>"
+      (rh '(video :loop true))))
+
+  (deftest "muted"
+    (assert-equal "<video muted></video>"
+      (rh '(video :muted true))))
+
+  (deftest "controls"
+    (assert-equal "<audio controls></audio>"
+      (rh '(audio :controls true))))
+
+  (deftest "selected"
+    (assert-equal "<option selected>yes</option>"
+      (rh '(option :selected true "yes"))))
+
+  (deftest "open (details)"
+    (assert-equal "<details open></details>"
+      (rh '(details :open true))))
+
+  (deftest "defer"
+    (assert-equal "<script defer></script>"
+      (rh '(script :defer true))))
+
+  (deftest "async"
+    (assert-equal "<script async></script>"
+      (rh '(script :async true))))
+
+  (deftest "novalidate"
+    (assert-equal "<form novalidate></form>"
+      (rh '(form :novalidate true)))))
+
+
+;; --------------------------------------------------------------------------
+;; 7. Regular attributes
+;; --------------------------------------------------------------------------
+
+(defsuite "html-regular-attrs"
+  (deftest "class attribute"
+    (assert-equal "<div class=\"container\"></div>"
+      (rh '(div :class "container"))))
+
+  (deftest "id attribute"
+    (assert-equal "<div id=\"main\"></div>"
+      (rh '(div :id "main"))))
+
+  (deftest "style attribute"
+    (assert-equal "<div style=\"color: red\"></div>"
+      (rh '(div :style "color: red"))))
+
+  (deftest "data-* attribute"
+    (assert-equal "<div data-value=\"42\"></div>"
+      (rh '(div :data-value "42"))))
+
+  (deftest "aria-* attribute"
+    (assert-equal "<div aria-label=\"close\"></div>"
+      (rh '(div :aria-label "close"))))
+
+  (deftest "multiple attributes"
+    (assert-equal "<a href=\"/\" class=\"link\">home</a>"
+      (rh '(a :href "/" :class "link" "home"))))
+
+  (deftest "nil attribute omitted"
+    (assert-equal "<div></div>"
+      (rh '(div :class nil))))
+
+  (deftest "numeric attribute value"
+    (assert-equal "<input maxlength=\"10\" />"
+      (rh '(input :maxlength 10)))))
+
+
+;; --------------------------------------------------------------------------
+;; 8. Fragments — children without wrapper
+;; --------------------------------------------------------------------------
+
+(defsuite "html-fragments"
+  (deftest "fragment renders children without wrapper"
+    (assert-equal "<p>a</p><p>b</p>"
+      (rh '(<> (p "a") (p "b")))))
+
+  (deftest "empty fragment"
+    (assert-equal "" (rh '(<>))))
+
+  (deftest "fragment with text"
+    (assert-equal "hello world"
+      (rh '(<> "hello " "world"))))
+
+  (deftest "nested fragment"
+    (assert-equal "<p>a</p><p>b</p>"
+      (rh '(<> (<> (p "a")) (p "b"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 9. Raw HTML — unescaped passthrough
+;; --------------------------------------------------------------------------
+
+(defsuite "html-raw"
+  (deftest "raw! passes through unescaped"
+    (assert-equal "<b>bold</b>"
+      (rh '(raw! "<b>bold</b>"))))
+
+  (deftest "raw! with multiple args"
+    (assert-equal "<em>a</em><em>b</em>"
+      (rh '(raw! "<em>a</em>" "<em>b</em>")))))
+
+
+;; --------------------------------------------------------------------------
+;; 10. Heading levels
+;; --------------------------------------------------------------------------
+
+(defsuite "html-headings"
+  (deftest "h1" (assert-equal "<h1>title</h1>" (rh '(h1 "title"))))
+  (deftest "h2" (assert-equal "<h2>sub</h2>" (rh '(h2 "sub"))))
+  (deftest "h3" (assert-equal "<h3>sec</h3>" (rh '(h3 "sec"))))
+  (deftest "h4" (assert-equal "<h4>sub</h4>" (rh '(h4 "sub"))))
+  (deftest "h5" (assert-equal "<h5>sub</h5>" (rh '(h5 "sub"))))
+  (deftest "h6" (assert-equal "<h6>sub</h6>" (rh '(h6 "sub")))))
+
+
+;; --------------------------------------------------------------------------
+;; 11. Lists (HTML)
+;; --------------------------------------------------------------------------
+
+(defsuite "html-lists"
+  (deftest "unordered list"
+    (assert-equal "<ul><li>a</li><li>b</li></ul>"
+      (rh '(ul (li "a") (li "b")))))
+
+  (deftest "ordered list"
+    (assert-equal "<ol><li>1</li><li>2</li></ol>"
+      (rh '(ol (li "1") (li "2")))))
+
+  (deftest "definition list"
+    (assert-equal "<dl><dt>term</dt><dd>def</dd></dl>"
+      (rh '(dl (dt "term") (dd "def"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 12. Tables
+;; --------------------------------------------------------------------------
+
+(defsuite "html-tables"
+  (deftest "basic table"
+    (assert-equal "<table><tr><td>cell</td></tr></table>"
+      (rh '(table (tr (td "cell"))))))
+
+  (deftest "table with header"
+    (assert-equal "<table><thead><tr><th>col</th></tr></thead><tbody><tr><td>val</td></tr></tbody></table>"
+      (rh '(table (thead (tr (th "col"))) (tbody (tr (td "val"))))))))
+
+
+;; --------------------------------------------------------------------------
+;; 13. Forms
+;; --------------------------------------------------------------------------
+
+(defsuite "html-forms"
+  (deftest "form with action"
+    (assert-equal "<form action=\"/submit\"></form>"
+      (rh '(form :action "/submit"))))
+
+  (deftest "input types"
+    (assert-equal "<input type=\"email\" />"
+      (rh '(input :type "email"))))
+
+  (deftest "textarea"
+    (assert-equal "<textarea>content</textarea>"
+      (rh '(textarea "content"))))
+
+  (deftest "select with options"
+    (assert-equal "<select><option>a</option><option>b</option></select>"
+      (rh '(select (option "a") (option "b")))))
+
+  (deftest "button"
+    (assert-equal "<button type=\"submit\">go</button>"
+      (rh '(button :type "submit" "go"))))
+
+  (deftest "label with for"
+    (assert-equal "<label for=\"name\">Name</label>"
+      (rh '(label :for "name" "Name"))))
+
+  (deftest "fieldset and legend"
+    (assert-equal "<fieldset><legend>group</legend></fieldset>"
+      (rh '(fieldset (legend "group"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 14. Media elements
+;; --------------------------------------------------------------------------
+
+(defsuite "html-media"
+  (deftest "video with src"
+    (assert-equal "<video src=\"v.mp4\"></video>"
+      (rh '(video :src "v.mp4"))))
+
+  (deftest "audio with controls"
+    (assert-equal "<audio controls></audio>"
+      (rh '(audio :controls true))))
+
+  (deftest "iframe"
+    (assert-equal "<iframe src=\"page.html\"></iframe>"
+      (rh '(iframe :src "page.html"))))
+
+  (deftest "canvas"
+    (assert-equal "<canvas width=\"100\" height=\"100\"></canvas>"
+      (rh '(canvas :width 100 :height 100))))
+
+  (deftest "picture with source and img"
+    (assert-equal "<picture><source srcset=\"photo.webp\" /><img src=\"photo.jpg\" /></picture>"
+      (rh '(picture (source :srcset "photo.webp") (img :src "photo.jpg"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 15. Semantic elements
+;; --------------------------------------------------------------------------
+
+(defsuite "html-semantic"
+  (deftest "header" (assert-equal "<header>h</header>" (rh '(header "h"))))
+  (deftest "nav" (assert-equal "<nav>n</nav>" (rh '(nav "n"))))
+  (deftest "main" (assert-equal "<main>m</main>" (rh '(main "m"))))
+  (deftest "section" (assert-equal "<section>s</section>" (rh '(section "s"))))
+  (deftest "article" (assert-equal "<article>a</article>" (rh '(article "a"))))
+  (deftest "aside" (assert-equal "<aside>a</aside>" (rh '(aside "a"))))
+  (deftest "footer" (assert-equal "<footer>f</footer>" (rh '(footer "f"))))
+  (deftest "details and summary"
+    (assert-equal "<details><summary>more</summary><p>info</p></details>"
+      (rh '(details (summary "more") (p "info")))))
+  (deftest "figure and figcaption"
+    (assert-equal "<figure><img src=\"x.jpg\" /><figcaption>cap</figcaption></figure>"
+      (rh '(figure (img :src "x.jpg") (figcaption "cap"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 16. SVG elements
+;; --------------------------------------------------------------------------
+
+(defsuite "html-svg"
+  (deftest "svg container"
+    (assert-equal "<svg viewBox=\"0 0 100 100\"></svg>"
+      (rh '(svg :viewBox "0 0 100 100"))))
+
+  (deftest "circle"
+    (assert-equal "<circle cx=\"50\" cy=\"50\" r=\"40\"></circle>"
+      (rh '(circle :cx 50 :cy 50 :r 40))))
+
+  (deftest "rect"
+    (assert-equal "<rect width=\"100\" height=\"50\"></rect>"
+      (rh '(rect :width 100 :height 50))))
+
+  (deftest "path"
+    (assert-equal "<path d=\"M0 0 L100 100\"></path>"
+      (rh '(path :d "M0 0 L100 100"))))
+
+  (deftest "g with transform"
+    (assert-equal "<g transform=\"translate(10,20)\"></g>"
+      (rh '(g :transform "translate(10,20)"))))
+
+  (deftest "text element"
+    (assert-equal "<text x=\"10\" y=\"20\">label</text>"
+      (rh '(text :x 10 :y 20 "label")))))
+
+
+;; --------------------------------------------------------------------------
+;; 17. Control flow in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-control-flow"
+  (deftest "if true renders then-branch"
+    (assert-equal "<p>yes</p>"
+      (rh '(if true (p "yes") (p "no")))))
+
+  (deftest "if false renders else-branch"
+    (assert-equal "<p>no</p>"
+      (rh '(if false (p "yes") (p "no")))))
+
+  (deftest "if false without else renders empty"
+    (assert-equal "" (rh '(if false (p "x")))))
+
+  (deftest "when true renders body"
+    (assert-equal "<p>ok</p>"
+      (rh '(when true (p "ok")))))
+
+  (deftest "when false renders empty"
+    (assert-equal "" (rh '(when false (p "x")))))
+
+  (deftest "cond renders matching branch"
+    (assert-equal "<p>b</p>"
+      (rh '(cond false (p "a") true (p "b")))))
+
+  (deftest "cond else branch"
+    (assert-equal "<p>c</p>"
+      (rh '(cond false (p "a") :else (p "c"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 18. Let bindings in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-let"
+  (deftest "let binding used in template"
+    (assert-equal "<p>hello</p>"
+      (rh '(let ((x "hello")) (p x)))))
+
+  (deftest "let with multiple bindings"
+    (assert-equal "<p>helloworld</p>"
+      (rh '(let ((a "hello") (b "world")) (p a b)))))
+
+  (deftest "nested let"
+    (assert-equal "<div><p>inner</p></div>"
+      (rh '(let ((x "inner")) (div (let ((y x)) (p y))))))))
+
+
+;; --------------------------------------------------------------------------
+;; 19. Map / for-each in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-iteration"
+  (deftest "map over items"
+    (assert-equal "<li>a</li><li>b</li><li>c</li>"
+      (rh '(map (fn (x) (li x)) (list "a" "b" "c")))))
+
+  (deftest "for-each renders items"
+    (assert-equal "<p>1</p><p>2</p>"
+      (rh '(for-each (fn (x) (p (str x))) (list 1 2)))))
+
+  (deftest "map-indexed"
+    (assert-equal "<li>0: a</li><li>1: b</li>"
+      (rh '(map-indexed (fn (i x) (li (str i ": " x))) (list "a" "b"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 20. Components
+;; --------------------------------------------------------------------------
+
+(defsuite "html-components"
+  (deftest "simple component"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defcomp ~card (&key title) (div :class "card" (h2 title))) env)
+      (assert-equal "<div class=\"card\"><h2>hello</h2></div>"
+        (rh-env '(~card :title "hello") env))))
+
+  (deftest "component with children"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defcomp ~box (&rest children) (div :class "box" children)) env)
+      (assert-equal "<div class=\"box\"><p>inner</p></div>"
+        (rh-env '(~box (p "inner")) env))))
+
+  (deftest "component with keyword and children"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defcomp ~panel (&key title &rest children)
+                    (section (h2 title) children)) env)
+      (assert-equal "<section><h2>Title</h2><p>body</p></section>"
+        (rh-env '(~panel :title "Title" (p "body")) env))))
+
+  (deftest "nested components"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defcomp ~inner (&key text) (em text)) env)
+      (eval-expr '(defcomp ~outer (&key text) (div (~inner :text text))) env)
+      (assert-equal "<div><em>hi</em></div>"
+        (rh-env '(~outer :text "hi") env)))))
+
+
+;; --------------------------------------------------------------------------
+;; 21. Macros
+;; --------------------------------------------------------------------------
+
+(defsuite "html-macros"
+  (deftest "macro expands and renders"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defmacro ~wrap (body)
+                    `(div :class "wrapped" ,body)) env)
+      (assert-equal "<div class=\"wrapped\"><p>hello</p></div>"
+        (rh-env '(~wrap (p "hello")) env)))))
+
+
+;; --------------------------------------------------------------------------
+;; 22. Begin/do — multi-expression body
+;; --------------------------------------------------------------------------
+
+(defsuite "html-begin"
+  (deftest "do renders all expressions"
+    (assert-equal "<p>a</p><p>b</p>"
+      (rh '(do (p "a") (p "b")))))
+
+  (deftest "begin renders all expressions"
+    (assert-equal "<h1>title</h1><p>body</p>"
+      (rh '(begin (h1 "title") (p "body"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 23. Letrec in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-letrec"
+  (deftest "letrec with side-effect rendering"
+    (assert-equal "<li>a</li><li>b</li>"
+      (rh '(letrec ((items (list "a" "b")))
+              (do (map (fn (x) (li x)) items)))))))
+
+
+;; --------------------------------------------------------------------------
+;; 24. Scope/provide in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-scope"
+  (deftest "scope renders body"
+    (assert-equal "<ul><li>inside</li></ul>"
+      (rh '(scope "items"
+              (ul (li "inside"))))))
+
+  (deftest "provide renders body"
+    (assert-equal "<div>content</div>"
+      (rh '(provide "theme" "dark"
+              (div "content"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 25. Other elements
+;; --------------------------------------------------------------------------
+
+(defsuite "html-other-elements"
+  (deftest "pre preserves structure"
+    (assert-equal "<pre>code here</pre>"
+      (rh '(pre "code here"))))
+
+  (deftest "code element"
+    (assert-equal "<code>x = 1</code>"
+      (rh '(code "x = 1"))))
+
+  (deftest "blockquote"
+    (assert-equal "<blockquote>quote</blockquote>"
+      (rh '(blockquote "quote"))))
+
+  (deftest "abbr with title"
+    (assert-equal "<abbr title=\"HyperText Markup Language\">HTML</abbr>"
+      (rh '(abbr :title "HyperText Markup Language" "HTML"))))
+
+  (deftest "time with datetime"
+    (assert-equal "<time datetime=\"2026-01-01\">New Year</time>"
+      (rh '(time :datetime "2026-01-01" "New Year"))))
+
+  (deftest "dialog"
+    (assert-equal "<dialog open>content</dialog>"
+      (rh '(dialog :open true "content"))))
+
+  (deftest "template"
+    (assert-equal "<template>inner</template>"
+      (rh '(template "inner"))))
+
+  (deftest "slot with name"
+    (assert-equal "<slot name=\"header\"></slot>"
+      (rh '(slot :name "header"))))
+
+  (deftest "noscript"
+    (assert-equal "<noscript>fallback</noscript>"
+      (rh '(noscript "fallback")))))
+
+
+;; --------------------------------------------------------------------------
+;; 26. Islands — defisland with hydration markers
+;; --------------------------------------------------------------------------
+
+(defsuite "html-islands"
+  (deftest "island renders with data-sx-island attribute"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defisland ~counter (&key start)
+                    (span (str "count: " start))) env)
+      (let ((html (rh-env '(~counter :start 0) env)))
+        ;; Should contain the island marker
+        (assert-true (string-contains? html "data-sx-island"))
+        ;; Should contain rendered content
+        (assert-true (string-contains? html "count: 0")))))
+
+  (deftest "island name appears in marker"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defisland ~toggle (&key label)
+                    (button label)) env)
+      (let ((html (rh-env '(~toggle :label "click") env)))
+        (assert-true (string-contains? html "toggle"))
+        (assert-true (string-contains? html "click")))))
+
+  (deftest "island with children"
+    (let ((env (env-extend (test-env))))
+      (eval-expr '(defisland ~wrapper (&rest children)
+                    (div :class "island" children)) env)
+      (let ((html (rh-env '(~wrapper (p "inside")) env)))
+        (assert-true (string-contains? html "data-sx-island"))
+        (assert-true (string-contains? html "<p>inside</p>"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 27. Lakes — server-morphable slots within islands
+;; --------------------------------------------------------------------------
+
+(defsuite "html-lakes"
+  (deftest "lake renders with data-sx-lake attribute"
+    (let ((env (env-extend (test-env))))
+      (let ((html (rh-env '(lake :id "content" (p "hello")) env)))
+        (assert-true (string-contains? html "data-sx-lake"))
+        (assert-true (string-contains? html "content"))
+        (assert-true (string-contains? html "<p>hello</p>")))))
+
+  (deftest "lake with custom tag"
+    (let ((env (env-extend (test-env))))
+      (let ((html (rh-env '(lake :id "nav" :tag "nav" (a "link")) env)))
+        (assert-true (starts-with? html "<nav"))
+        (assert-true (string-contains? html "<a>link</a>"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 28. Marshes — reactive server-morphable slots
+;; --------------------------------------------------------------------------
+
+(defsuite "html-marshes"
+  (deftest "marsh renders with data-sx-marsh attribute"
+    (let ((env (env-extend (test-env))))
+      (let ((html (rh-env '(marsh :id "feed" (li "item")) env)))
+        (assert-true (string-contains? html "data-sx-marsh"))
+        (assert-true (string-contains? html "feed"))
+        (assert-true (string-contains? html "<li>item</li>")))))
+
+  (deftest "marsh with custom tag"
+    (let ((env (env-extend (test-env))))
+      (let ((html (rh-env '(marsh :id "list" :tag "ul" (li "a") (li "b")) env)))
+        (assert-true (starts-with? html "<ul"))
+        (assert-true (string-contains? html "<li>a</li>"))
+        (assert-true (string-contains? html "<li>b</li>"))))))
+
+
+;; --------------------------------------------------------------------------
+;; 29. Thread macro in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-threading"
+  (deftest "thread-first in template context"
+    (assert-equal "<p>HELLO</p>"
+      (rh '(p (-> "hello" upper))))))
+
+
+;; --------------------------------------------------------------------------
+;; 30. Define in templates
+;; --------------------------------------------------------------------------
+
+(defsuite "html-define-in-template"
+  (deftest "define then use in same template"
+    (assert-equal "<p>42</p>"
+      (rh '(do (define x 42) (p (str x))))))
+
+  (deftest "defcomp then use"
+    (assert-equal "<em>hi</em>"
+      (rh '(do (defcomp ~tag (&key text) (em text))
+               (~tag :text "hi"))))))