fix(core dom find_form, pat autosubmit): Add support for pat-subform.

Subform was recently lost when introducing dom.find_form.
Now subform support is back in pat-autosubmit.

src/core/dom.js

@@ -569,11 +569,12 @@ const element_uuid = (el) => {
 const find_form = (el) => {
     // Prefer input.form which allows for input outside form elements and fall
     // back to search for a parent form.
-    return (
+    const form =
+        el.closest(".pat-subform") || // Special Patternslib subform concept has precedence.
         el.form ||
         el.querySelector("input, select, textarea, button")?.form ||
-        el.closest("form")
-    );
+        el.closest("form");
+    return form;
 };
 
 const dom = {

src/core/dom.test.js

@@ -1002,4 +1002,18 @@ describe("find_form", function () {
         const form = document.querySelector("#the-form");
         expect(dom.find_form(el)).toBe(form);
     });
+
+    it("example 9 - subform support", function () {
+        // Subform support. Subforms have precedence over forms.
+        document.body.innerHTML = `
+            <form>
+                <div class="pat-subform">
+                    <button></button>
+                </div>
+            </form>
+        `;
+        const el = document.querySelector("button");
+        const subform = document.querySelector(".pat-subform");
+        expect(dom.find_form(el)).toBe(subform);
+    });
 });

src/pat/auto-submit/auto-submit.test.js

@@ -187,7 +187,7 @@ describe("pat-autosubmit", function () {
             expect(submit_form_dispatched).toBe(true);
         });
 
-        it("2.6 - when pat-autosubmit is defined not on aform element", async function () {
+        it("2.6 - when pat-autosubmit is defined not on a form element", async function () {
             document.body.innerHTML = `
               <form>
                 <div
@@ -211,6 +211,40 @@ describe("pat-autosubmit", function () {
             await utils.timeout(1);
             expect(submit_form_dispatched).toBe(true);
         });
+
+        it("2.7 - directly on a pat-subform", async function () {
+            document.body.innerHTML = `
+              <form>
+                <div class="pat-subform">
+                    <input
+                        class="pat-autosubmit"
+                        data-pat-autosubmit="delay: 0"
+                        name="q">
+                </div>
+              </form>
+            `;
+            const input = document.querySelector("input");
+            const subform = document.querySelector(".pat-subform");
+            const autosubmit = document.querySelector(".pat-autosubmit");
+            new Pattern(autosubmit);
+
+            // The submit event should be invoked on the subform.
+            let submit_subform_dispatched = false;
+            subform.addEventListener("submit", () => {
+                submit_subform_dispatched = true;
+            });
+
+            // The submit event should also bubble up to the form.
+            let submit_form_dispatched = false;
+            document.querySelector("form").addEventListener("submit", () => {
+                submit_form_dispatched = true;
+            });
+
+            input.dispatchEvent(events.input_event());
+            await utils.timeout(1);
+            expect(submit_subform_dispatched).toBe(true);
+            expect(submit_form_dispatched).toBe(true);
+        });
     });
 
     describe("3 - Parsing of the delay option", function () {