From 4e4b9574b7dba9db6433ccd65bd506bda7f6f6cc Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Tue, 20 Dec 2022 17:50:10 +0100
Subject: [PATCH 1/8] WP_HTML_Tag_Processor: Implement get_attribute_names()

---
 .../html/class-wp-html-tag-processor.php      | 26 +++++++++++++++++++
 phpunit/html/wp-html-tag-processor-test.php   | 12 +++++++++
 2 files changed, 38 insertions(+)

diff --git a/lib/experimental/html/class-wp-html-tag-processor.php b/lib/experimental/html/class-wp-html-tag-processor.php
index 0dfa57f30f2aab..7f8286db76654a 100644
--- a/lib/experimental/html/class-wp-html-tag-processor.php
+++ b/lib/experimental/html/class-wp-html-tag-processor.php
@@ -1412,6 +1412,32 @@ public function get_attribute( $name ) {
 		return html_entity_decode( $raw_value );
 	}
 
+	/**
+	 * Returns the names of all attributes in the currently-opened tag.
+	 *
+	 * Example:
+	 * <code>
+	 *     $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
+	 *     $p->next_tag( [ 'class_name' => 'test' ] ) === true;
+	 *     $p->get_attribute_names() === array( 'enabled', 'class', 'data-test-id' );
+	 *
+	 *     $p->next_tag( [] ) === false;
+	 *     $p->get_attribute_names() === null;
+	 * </code>
+	 *
+	 * @since 6.2.0
+	 *
+	 * @param string $prefix Prefix of attributes whose value is requested.
+	 * @return array|null List of attribute names, or `null` if not at a tag.
+	 */
+	function get_attribute_names() {
+		if ( null === $this->tag_name_starts_at ) {
+			return null;
+		}
+
+		return array_keys( $this->attributes );
+	}
+
 	/**
 	 * Returns the lowercase name of the currently-opened tag.
 	 *
diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index e6b3d4d8071af5..fafd02cc7b15be 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -151,6 +151,18 @@ public function test_attributes_parser_treats_slash_as_attribute_separator() {
 		$this->assertSame( 'test', $p->get_attribute( 'e' ), 'Accessing an existing e="test" did not return "test"' );
 	}
 
+	/**
+	 * @covers WP_HTML_Tag_Processor::get_attribute_names
+	 */
+	public function test_get_attribute_names() {
+		$p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
+		$p->next_tag();
+		$this->assertSame(
+			array( 'enabled', 'class', 'data-test-id' ),
+			$p->get_attribute_names()
+		);
+	}
+
 	/**
 	 * @ticket 56299
 	 *

From 157301039737f0e1d784ac257f94f00613048db5 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Thu, 22 Dec 2022 11:53:46 +0100
Subject: [PATCH 2/8] Remove superfluous parameter comment

---
 lib/experimental/html/class-wp-html-tag-processor.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/experimental/html/class-wp-html-tag-processor.php b/lib/experimental/html/class-wp-html-tag-processor.php
index 7f8286db76654a..22ff19a5e0f162 100644
--- a/lib/experimental/html/class-wp-html-tag-processor.php
+++ b/lib/experimental/html/class-wp-html-tag-processor.php
@@ -1427,7 +1427,6 @@ public function get_attribute( $name ) {
 	 *
 	 * @since 6.2.0
 	 *
-	 * @param string $prefix Prefix of attributes whose value is requested.
 	 * @return array|null List of attribute names, or `null` if not at a tag.
 	 */
 	function get_attribute_names() {

From 8be4ac9844c350f91cc7486ba4edff4820d6b5b6 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 14:45:02 +0100
Subject: [PATCH 3/8] Move test down

---
 phpunit/html/wp-html-tag-processor-test.php | 24 ++++++++++-----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index fafd02cc7b15be..cd59df546ab163 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -151,18 +151,6 @@ public function test_attributes_parser_treats_slash_as_attribute_separator() {
 		$this->assertSame( 'test', $p->get_attribute( 'e' ), 'Accessing an existing e="test" did not return "test"' );
 	}
 
-	/**
-	 * @covers WP_HTML_Tag_Processor::get_attribute_names
-	 */
-	public function test_get_attribute_names() {
-		$p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
-		$p->next_tag();
-		$this->assertSame(
-			array( 'enabled', 'class', 'data-test-id' ),
-			$p->get_attribute_names()
-		);
-	}
-
 	/**
 	 * @ticket 56299
 	 *
@@ -207,6 +195,18 @@ public function test_set_attribute_is_case_insensitive() {
 		$this->assertEquals( '<div data-enabled="abc">Test</div>', $p->get_updated_html(), 'A case-insensitive set_attribute call did not update the existing attribute.' );
 	}
 
+	/**
+	 * @covers WP_HTML_Tag_Processor::get_attribute_names
+	 */
+	public function test_get_attribute_names() {
+		$p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
+		$p->next_tag();
+		$this->assertSame(
+			array( 'enabled', 'class', 'data-test-id' ),
+			$p->get_attribute_names()
+		);
+	}
+
 	/**
 	 * @ticket 56299
 	 *

From 8c51859ddc4eadb1ae483cd692f0b41f966247c6 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 15:09:12 +0100
Subject: [PATCH 4/8] Add test for get_attribute() when in closing tag

---
 phpunit/html/wp-html-tag-processor-test.php | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index cd59df546ab163..6962ed8ddf211b 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -74,6 +74,19 @@ public function test_get_attribute_returns_null_when_not_in_open_tag() {
 		$this->assertNull( $p->get_attribute( 'class' ), 'Accessing an attribute of a non-existing tag did not return null' );
 	}
 
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers next_tag
+	 * @covers get_attribute
+	 */
+	public function test_get_attribute_returns_null_when_in_closing_tag() {
+		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		$this->assertTrue( $p->next_tag( 'div' ), 'Querying an existing tag did not return true' );
+		$this->assertTrue( $p->next_tag( array( 'tag_closers' => 'visit' ) ), 'Querying an existing closing tag did not return true' );
+		$this->assertNull( $p->get_attribute( 'class' ), 'Accessing an attribute of a closing tag did not return null' );
+	}
+
 	/**
 	 * @ticket 56299
 	 *

From ca06c6483a8a9399f401f5bf5a35bc4c463e2382 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 15:20:44 +0100
Subject: [PATCH 5/8] Add more get_attribute_names tests()

---
 phpunit/html/wp-html-tag-processor-test.php | 50 ++++++++++++++++++++-
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index 6962ed8ddf211b..eddfc68fbe8453 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -209,9 +209,55 @@ public function test_set_attribute_is_case_insensitive() {
 	}
 
 	/**
-	 * @covers WP_HTML_Tag_Processor::get_attribute_names
+	 * @ticket 56299
+	 *
+	 * @covers get_attribute_names
+	 */
+	public function test_get_attribute_names_returns_null_before_finding_tags() {
+		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		$this->assertNull( $p->get_attribute_names() );
+	}
+
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers get_attribute
+	 */
+	public function test_get_attribute_names_returns_null_when_not_in_open_tag() {
+		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		$p->next_tag( 'p' );
+		$this->assertNull( $p->get_attribute_names(), 'Accessing attributes of a non-existing tag did not return null' );
+	}
+
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers get_attribute_names
+	 */
+	public function test_get_attribute_names_returns_null_when_in_closing_tag() {
+		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		$p->next_tag( 'div' );
+		$p->next_tag( array( 'tag_closers' => 'visit' ) );
+		$this->assertNull( $p->get_attribute_names(), 'Accessing attributes of a closing tag did not return null' );
+	}
+
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers get_attribute_names
+	 */
+	public function test_get_attribute_names_returns_empty_array_when_no_attributes_present() {
+		$p = new WP_HTML_Tag_Processor( '<div>Test</div>' );
+		$p->next_tag( 'div' );
+		$this->assertSame( array(), $p->get_attribute_names(), 'Accessing the attributes on a tag without any did not return an empty array' );
+	}
+
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers get_attribute_names
 	 */
-	public function test_get_attribute_names() {
+	public function test_get_attribute_names_returns_attribute_names() {
 		$p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
 		$p->next_tag();
 		$this->assertSame(

From 2dbf838a66fdb6a5e67194b2ca277932c5bbd508 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 15:20:53 +0100
Subject: [PATCH 6/8] Fix implementation

---
 lib/experimental/html/class-wp-html-tag-processor.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/experimental/html/class-wp-html-tag-processor.php b/lib/experimental/html/class-wp-html-tag-processor.php
index 22ff19a5e0f162..e50cb3d43f76ea 100644
--- a/lib/experimental/html/class-wp-html-tag-processor.php
+++ b/lib/experimental/html/class-wp-html-tag-processor.php
@@ -1430,7 +1430,7 @@ public function get_attribute( $name ) {
 	 * @return array|null List of attribute names, or `null` if not at a tag.
 	 */
 	function get_attribute_names() {
-		if ( null === $this->tag_name_starts_at ) {
+		if ( $this->is_closing_tag || null === $this->tag_name_starts_at ) {
 			return null;
 		}
 

From 5b248c08e6228422f4aefd6bceab5c724c6841f7 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 15:58:57 +0100
Subject: [PATCH 7/8] Verify that get_attribute_names finds attribute added by
 set_attribute

---
 phpunit/html/wp-html-tag-processor-test.php | 23 +++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index eddfc68fbe8453..56b7f312971cf5 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -266,6 +266,29 @@ public function test_get_attribute_names_returns_attribute_names() {
 		);
 	}
 
+	/**
+	 * @ticket 56299
+	 *
+	 * @covers set_attribute
+	 * @covers get_updated_html
+	 * @covers get_attribute_names
+	 */
+	public function test_get_attribute_names_returns_attribute_added_by_set_attribute() {
+		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		$p->next_tag();
+		$p->set_attribute( 'test-attribute', 'test-value' );
+		$this->assertSame(
+			'<div test-attribute="test-value" class="test">Test</div>',
+			$p->get_updated_html(),
+			"Updated HTML doesn't include attribute added via set_attribute"
+		);
+		$this->assertSame(
+			array( 'test-attribute', 'class' ),
+			$p->get_attribute_names(),
+			"Accessing attribute names doesn't find attribute added via set_attribute"
+		);
+	}
+
 	/**
 	 * @ticket 56299
 	 *

From 9c3ab7e3997f4e5978c1bbb5762f26437cdb652b Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Mon, 2 Jan 2023 16:40:04 +0100
Subject: [PATCH 8/8] Fix PHPDoc string

---
 phpunit/html/wp-html-tag-processor-test.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/phpunit/html/wp-html-tag-processor-test.php b/phpunit/html/wp-html-tag-processor-test.php
index 56b7f312971cf5..03bd4914102025 100644
--- a/phpunit/html/wp-html-tag-processor-test.php
+++ b/phpunit/html/wp-html-tag-processor-test.php
@@ -221,7 +221,7 @@ public function test_get_attribute_names_returns_null_before_finding_tags() {
 	/**
 	 * @ticket 56299
 	 *
-	 * @covers get_attribute
+	 * @covers get_attribute_names
 	 */
 	public function test_get_attribute_names_returns_null_when_not_in_open_tag() {
 		$p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );