fix(runtime): make form defaults post declaratively

req: form/002

req: examples/005

req: convention/004

slhx-js/runtime/slhx.js

@@ -123,7 +123,7 @@
     const abort = new AbortController();
     let finish;
     const done = new Promise((resolve) => { finish = resolve; });
-    const method = String((form && form.method) || "POST").toUpperCase();
+    const method = String((form && form.getAttribute("method")) || "POST").toUpperCase();
     const body = method === "GET" || method === "HEAD" ? undefined : requestBody(data, multipart);
     const headers = { "X-SLHX-Partial": "1", "Accept": "application/slhx, text/html" };
     if (body instanceof URLSearchParams) headers["Content-Type"] = "application/x-www-form-urlencoded;charset=UTF-8";

slhx-js/tests/runtime.rs

@@ -3,6 +3,7 @@ fn runtime_posts_urlencoded_forms_by_default() {
     let source = slhx_js::RUNTIME_JS;
 
     assert!(source.contains("new URLSearchParams()"));
+    assert!(source.contains("form.getAttribute(\"method\")"));
     assert!(source.contains("multipart/form-data"));
     assert!(source.contains("const body = method === \"GET\" || method === \"HEAD\" ? undefined : requestBody(data, multipart)"));
     assert!(source.contains("application/x-www-form-urlencoded;charset=UTF-8"));