From 966c68ae0e8c2561d715023802bf87d165a76899 Mon Sep 17 00:00:00 2001
From: sideshowbarker <mike@w3.org>
Date: Mon, 23 Dec 2024 21:15:05 +0900
Subject: [PATCH] LibWeb: Align accname alt-vs-title behavior w/ HTML-AAM spec
 & WPT tests
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The https://wpt.fyi/results/accname/name/comp_tooltip.tentative.html
test was recently added by moving an existing subtest out from the test
at https://wpt.fyi/results/accname/name/comp_tooltip.html, and changing
the test expectations to match the HTML-AAM spec requirements at
https://w3c.github.io/html-aam/#img-element-accessible-name-computation.
See https://github.com/web-platform-tests/wpt/pull/49552.

So this code change updates Ladybird to match the updated WPT test
expectations — and to match the existing HTML-AAM spec requirements.
---
 Libraries/LibWeb/DOM/Node.cpp                 | 12 ++++++----
 .../accname/name/comp_tooltip.tentative.txt   |  6 +++++
 .../wpt-import/accname/name/comp_tooltip.txt  |  5 ++--
 .../wpt-import/accname/name/comp_tooltip.html |  3 +--
 .../accname/name/comp_tooltip.tentative.html  | 23 +++++++++++++++++++
 5 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.tentative.txt
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.tentative.html

diff --git a/Libraries/LibWeb/DOM/Node.cpp b/Libraries/LibWeb/DOM/Node.cpp
index 03c97a28789..4b458e032fc 100644
--- a/Libraries/LibWeb/DOM/Node.cpp
+++ b/Libraries/LibWeb/DOM/Node.cpp
@@ -2491,13 +2491,15 @@ ErrorOr<String> Node::name_or_description(NameOrDescription target, Document con
 
         // E. Host Language Label: Otherwise, if the current node's native markup provides an attribute (e.g. alt) or
         //    element (e.g. HTML label or SVG title) that defines a text alternative, return that alternative in the form
-        //    of a flat string as defined by the host language, unless the element is marked as presentational
-        //    (role="presentation" or role="none").
-        //
+        //    of a flat string as defined by the host language.
         // TODO: Confirm (through existing WPT test cases) whether HTMLLabelElement is already handled (by the code for
         // step C. “Embedded Control” above) in conformance with the spec requirements — and if not, then add handling.
-        if (role != ARIA::Role::presentation && role != ARIA::Role::none && is<HTML::HTMLImageElement>(*element))
-            return element->alternative_text().release_value();
+        //
+        // https://w3c.github.io/html-aam/#img-element-accessible-name-computation
+        // use alt attribute, even if its value is the empty string.
+        // See also https://wpt.fyi/results/accname/name/comp_tooltip.tentative.html.
+        if (is<HTML::HTMLImageElement>(*element) && element->has_attribute(HTML::AttributeNames::alt))
+            return element->get_attribute(HTML::AttributeNames::alt).value();
 
         // https://w3c.github.io/svg-aam/#mapping_additional_nd
         Optional<String> title_element_text;
diff --git a/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.tentative.txt b/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.tentative.txt
new file mode 100644
index 00000000000..89715e306e4
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.tentative.txt
@@ -0,0 +1,6 @@
+Harness status: OK
+
+Found 1 tests
+
+1 Pass
+Pass	img with tooltip label with empty alt
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.txt b/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.txt
index bc2df895889..0400e6dbd6b 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/accname/name/comp_tooltip.txt
@@ -1,14 +1,13 @@
 Harness status: OK
 
-Found 23 tests
+Found 22 tests
 
-23 Pass
+22 Pass
 Pass	link with img with tooltip label
 Pass	link with text with tooltip label and no contents
 Pass	link with text with tooltip label and contents
 Pass	div with text with tooltip label
 Pass	img with tooltip label without alt
-Pass	img with tooltip label with empty alt
 Pass	img with tooltip label with alt
 Pass	img with tooltip label without title
 Pass	select with tooltip label
diff --git a/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.html b/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.html
index 93e506bd0b3..d8864ca2d6d 100644
--- a/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.html
+++ b/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.html
@@ -13,12 +13,11 @@
 
 <p>Tests the <a href="https://w3c.github.io/accname/#comp_tooltip">#comp_tooltip</a> portions of the AccName <em>Name Computation</em> algorithm.</p>
 
-<a href="#" title="title" data-expectedlabel="title" data-testname="link with img with tooltip label" class="ex"><img alt="" src="data:image/gif;base65,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="></a>
+<a href="#" title="title" data-expectedlabel="title" data-testname="link with img with tooltip label" class="ex"><img alt="" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw=="></a>
 <a href="#" title="title" data-expectedlabel="title" data-testname="link with text with tooltip label and no contents" class="ex"></a>
 <a href="#" title="title" data-expectedlabel="contents" data-testname="link with text with tooltip label and contents" class="ex">contents</a>
 <div title="title" role="group" data-expectedlabel="title" data-testname="div with text with tooltip label" class="ex">contents</div><!-- Note: group role disallows nameFrom:contents -->
 <img title="title" data-expectedlabel="title" data-testname="img with tooltip label without alt" class="ex" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
-<img title="title" data-expectedlabel="title" alt="" data-testname="img with tooltip label with empty alt" class="ex" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
 <img title="title" data-expectedlabel="alt" alt="alt" data-testname="img with tooltip label with alt" class="ex" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
 <img data-expectedlabel="alt" alt="alt" data-testname="img with tooltip label without title" class="ex" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
 
diff --git a/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.tentative.html b/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.tentative.html
new file mode 100644
index 00000000000..10128588b6d
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/accname/name/comp_tooltip.tentative.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<html>
+<head>
+  <title>Name Comp: Tooltip (Tentative)</title>
+  <script src="../../resources/testharness.js"></script>
+  <script src="../../resources/testharnessreport.js"></script>
+  <script src="../../resources/testdriver.js"></script>
+  <script src="../../resources/testdriver-vendor.js"></script>
+  <script src="../../resources/testdriver-actions.js"></script>
+  <script src="../../wai-aria/scripts/aria-utils.js"></script>
+</head>
+<body>
+
+<p>Tests the tentative <a href="https://w3c.github.io/accname/#comp_tooltip">#comp_tooltip</a> portions of the AccName <em>Name Computation</em> algorithm.</p>
+
+<!-- Explanation in https://github.com/w3c/aria/pull/2378#issuecomment-2493635126 -->
+<img title="title" data-expectedlabel="" alt="" data-testname="img with tooltip label with empty alt" class="ex" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
+
+<script>
+AriaUtils.verifyLabelsBySelector(".ex");
+</script>
+</body>
+</html>