From 952433052e66ecc79057159f12f1d0e19ee1fa3c Mon Sep 17 00:00:00 2001
From: Pavel Shliak <shlyakpavel@gmail.com>
Date: Fri, 20 Dec 2024 21:26:49 +0400
Subject: [PATCH] LibWeb: Update FormData constructor to reflect the spec

---
 Libraries/LibWeb/XHR/FormData.cpp             |  30 +++++-
 Libraries/LibWeb/XHR/FormData.h               |   2 +-
 Libraries/LibWeb/XHR/FormData.idl             |   2 +-
 .../xhr/formdata/constructor-submitter.txt    |  15 +++
 .../xhr/formdata/constructor-submitter.html   | 100 ++++++++++++++++++
 5 files changed, 143 insertions(+), 6 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/xhr/formdata/constructor-submitter.txt
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/xhr/formdata/constructor-submitter.html

diff --git a/Libraries/LibWeb/XHR/FormData.cpp b/Libraries/LibWeb/XHR/FormData.cpp
index 3c1421f75b17..ef26f842a87f 100644
--- a/Libraries/LibWeb/XHR/FormData.cpp
+++ b/Libraries/LibWeb/XHR/FormData.cpp
@@ -9,7 +9,9 @@
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/FileAPI/Blob.h>
 #include <LibWeb/FileAPI/File.h>
+#include <LibWeb/HTML/FormAssociatedElement.h>
 #include <LibWeb/HTML/FormControlInfrastructure.h>
+#include <LibWeb/HTML/HTMLFormElement.h>
 #include <LibWeb/WebIDL/DOMException.h>
 #include <LibWeb/XHR/FormData.h>
 
@@ -18,17 +20,37 @@ namespace Web::XHR {
 GC_DEFINE_ALLOCATOR(FormData);
 
 // https://xhr.spec.whatwg.org/#dom-formdata
-WebIDL::ExceptionOr<GC::Ref<FormData>> FormData::construct_impl(JS::Realm& realm, GC::Ptr<HTML::HTMLFormElement> form)
+WebIDL::ExceptionOr<GC::Ref<FormData>> FormData::construct_impl(JS::Realm& realm, GC::Ptr<HTML::HTMLFormElement> form, Optional<GC::Ptr<HTML::HTMLElement>> submitter)
 {
     Vector<FormDataEntry> list;
     // 1. If form is given, then:
     if (form) {
-        // 1. Let list be the result of constructing the entry list for form.
+        // 1. If submitter is non-null, then:
+        if (submitter.has_value() && submitter.value()) {
+            auto& submitter_element = submitter.value();
+
+            // 1. If submitter is not a submit button, then throw a TypeError.
+            if (!is<HTML::FormAssociatedElement>(*submitter_element)) {
+                return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "Submitter is not associated with a form."sv };
+            }
+            auto* form_associated_element = dynamic_cast<HTML::FormAssociatedElement*>(submitter_element.ptr());
+
+            if (!form_associated_element->is_submit_button()) {
+                return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "Submitter is not a valid submit button."sv };
+            }
+            // 2. If submitter’s form owner is not form, then throw a "NotFoundError" DOMException.
+            auto* form_owner = form_associated_element->form();
+            if (form_owner && form_owner != form) {
+                return WebIDL::NotFoundError::create(realm, "Submitter does not belong to the provided form."_string);
+            }
+        }
+
+        // 2. Let list be the result of constructing the entry list for form.
         auto entry_list = TRY(construct_entry_list(realm, *form));
-        // 2. If list is null, then throw an "InvalidStateError" DOMException.
+        // 3. If list is null, then throw an "InvalidStateError" DOMException.
         if (!entry_list.has_value())
             return WebIDL::InvalidStateError::create(realm, "Form element does not contain any entries."_string);
-        // 3. Set this’s entry list to list.
+        // 4. Set this’s entry list to list.
         list = entry_list.release_value();
     }
 
diff --git a/Libraries/LibWeb/XHR/FormData.h b/Libraries/LibWeb/XHR/FormData.h
index fc37565dd819..a185bba9ce68 100644
--- a/Libraries/LibWeb/XHR/FormData.h
+++ b/Libraries/LibWeb/XHR/FormData.h
@@ -24,7 +24,7 @@ class FormData : public Bindings::PlatformObject {
 public:
     virtual ~FormData() override;
 
-    static WebIDL::ExceptionOr<GC::Ref<FormData>> construct_impl(JS::Realm&, GC::Ptr<HTML::HTMLFormElement> form = {});
+    static WebIDL::ExceptionOr<GC::Ref<FormData>> construct_impl(JS::Realm&, GC::Ptr<HTML::HTMLFormElement> form = {}, Optional<GC::Ptr<HTML::HTMLElement>> submitter = {});
     static WebIDL::ExceptionOr<GC::Ref<FormData>> construct_impl(JS::Realm&, Vector<FormDataEntry> entry_list);
 
     static WebIDL::ExceptionOr<GC::Ref<FormData>> create(JS::Realm&, Vector<DOMURL::QueryParam> entry_list);
diff --git a/Libraries/LibWeb/XHR/FormData.idl b/Libraries/LibWeb/XHR/FormData.idl
index fb844b2e7a8f..aa6f86a6d625 100644
--- a/Libraries/LibWeb/XHR/FormData.idl
+++ b/Libraries/LibWeb/XHR/FormData.idl
@@ -11,7 +11,7 @@ typedef (File or USVString) FormDataEntryValue;
 // https://xhr.spec.whatwg.org/#interface-formdata
 [Exposed=(Window,Worker)]
 interface FormData {
-    constructor(optional HTMLFormElement form);
+    constructor(optional HTMLFormElement form, optional HTMLElement? submitter = null);
 
     undefined append(USVString name, USVString value);
     undefined append(USVString name, Blob blobValue, optional USVString filename);
diff --git a/Tests/LibWeb/Text/expected/wpt-import/xhr/formdata/constructor-submitter.txt b/Tests/LibWeb/Text/expected/wpt-import/xhr/formdata/constructor-submitter.txt
new file mode 100644
index 000000000000..51492179cd02
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/xhr/formdata/constructor-submitter.txt
@@ -0,0 +1,15 @@
+Harness status: OK
+
+Found 9 tests
+
+6 Pass
+3 Fail
+Pass	FormData construction should allow a null submitter
+Pass	FormData construction should allow an undefined form and an undefined submitter
+Pass	FormData construction should allow an undefined form and a null submitter
+Pass	FormData construction should throw a TypeError if a non-null submitter is not a submit button
+Pass	FormData construction should throw a 'NotFoundError' DOMException if a non-null submitter is not owned by the form
+Fail	The constructed FormData object should contain an in-tree-order entry for a named submit button submitter
+Pass	The constructed FormData object should not contain an entry for an unnamed submit button submitter
+Fail	The constructed FormData object should contain in-tree-order entries for an activated Image Button submitter
+Fail	The constructed FormData object should contain in-tree-order entries for an unactivated Image Button submitter
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/xhr/formdata/constructor-submitter.html b/Tests/LibWeb/Text/input/wpt-import/xhr/formdata/constructor-submitter.html
new file mode 100644
index 000000000000..5e1626e97bf3
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/xhr/formdata/constructor-submitter.html
@@ -0,0 +1,100 @@
+<!DOCTYPE html>
+<meta charset='utf-8'>
+<link rel='help' href='https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#constructing-the-form-data-set'>
+<link ref='help' href='https://xhr.spec.whatwg.org/#dom-formdata'>
+<script src='../../resources/testharness.js'></script>
+<script src='../../resources/testharnessreport.js'></script>
+
+<button name=outerNamed value=GO form='myform'></button>
+<form id='myform' onsubmit='return false'>
+  <input name=n1 value=v1>
+  <button name=named value=GO></button>
+  <button id=unnamed value=unnamed></button>
+  <button form="another" name=unassociated value=unassociated></button>
+  <input type=image name=namedImage src='/media/1x1-green.png'></button>
+  <input type=image id=unnamedImage src='/media/1x1-green.png'></button>
+  <input type=image name=unactivatedImage src='/media/1x1-green.png'></button>
+  <input name=n3 value=v3>
+</form>
+
+<form id='another'>
+  <button name=unassociated2 value=unassociated></button>
+</form>
+
+<script>
+function assertFormDataEntries(formData, expectedEntries) {
+  const expectedEntryNames = expectedEntries.map((entry) => entry[0]);
+  const actualEntries = [...formData.entries()];
+  const actualEntryNames = actualEntries.map((entry) => entry[0]);
+  assert_array_equals(actualEntryNames, expectedEntryNames);
+  for (let i = 0; i < actualEntries.length; i++) {
+    assert_array_equals(actualEntries[i], expectedEntries[i]);
+  }
+}
+
+const form = document.querySelector('#myform');
+
+test(() => {
+  assertFormDataEntries(
+    new FormData(form, null),
+    [['n1', 'v1'], ['n3', 'v3']]
+  );
+}, 'FormData construction should allow a null submitter'); // the use case here is so web developers can avoid null checks, e.g. `new FormData(e.target, e.submitter)`
+
+test(() => {
+  assertFormDataEntries(new FormData(undefined, undefined), []);
+}, 'FormData construction should allow an undefined form and an undefined submitter');
+
+test(() => {
+  assertFormDataEntries(new FormData(undefined, null), []);
+}, 'FormData construction should allow an undefined form and a null submitter');
+
+test(() => {
+  assert_throws_js(TypeError, () => new FormData(form, document.querySelector('[name=n1]')));
+}, 'FormData construction should throw a TypeError if a non-null submitter is not a submit button');
+
+test(() => {
+  assert_throws_dom('NotFoundError', () => new FormData(form, document.querySelector('[name=unassociated]')));
+  assert_throws_dom('NotFoundError', () => new FormData(form, document.querySelector('[name=unassociated2]')));
+}, "FormData construction should throw a 'NotFoundError' DOMException if a non-null submitter is not owned by the form");
+
+test(() => {
+  assertFormDataEntries(
+    new FormData(form, document.querySelector('[name=named]')),
+    [['n1', 'v1'], ['named', 'GO'], ['n3', 'v3']]
+  );
+  assertFormDataEntries(
+    new FormData(form, document.querySelector('[name=outerNamed]')),
+    [['outerNamed', 'GO'], ['n1', 'v1'], ['n3', 'v3']]
+  );
+}, 'The constructed FormData object should contain an in-tree-order entry for a named submit button submitter');
+
+test(() => {
+  assertFormDataEntries(
+    new FormData(form, document.querySelector('#unnamed')),
+    [['n1', 'v1'], ['n3', 'v3']]
+  );
+}, 'The constructed FormData object should not contain an entry for an unnamed submit button submitter');
+
+test(() => {
+  const submitter1 = document.querySelector('[name=namedImage]');
+  submitter1.click();
+  const submitter2 = document.querySelector('#unnamedImage');
+  submitter2.click();
+  assertFormDataEntries(
+    new FormData(form, submitter1),
+    [['n1', 'v1'], ['namedImage.x', '0'], ['namedImage.y', '0'], ['n3', 'v3']]
+  );
+  assertFormDataEntries(
+    new FormData(form, submitter2),
+    [['n1', 'v1'], ['x', '0'], ['y', '0'], ['n3', 'v3']]
+  );
+}, 'The constructed FormData object should contain in-tree-order entries for an activated Image Button submitter');
+
+test(() => {
+  assertFormDataEntries(
+    new FormData(form, document.querySelector('[name=unactivatedImage]')),
+    [['n1', 'v1'], ['unactivatedImage.x', '0'], ['unactivatedImage.y', '0'], ['n3', 'v3']]
+  );
+}, 'The constructed FormData object should contain in-tree-order entries for an unactivated Image Button submitter');
+</script>