Implement CSS selectors

2024-11-23 01:44:06 +08:00 · 2024-04-27 23:25:37 +02:00 · 2024-04-27 23:25:37 +02:00 · 88da914910
commit 88da914910
parent 7defc23532
50 changed files with 4073 additions and 16 deletions
--- a/UPGRADING.INTERNALS
+++ b/UPGRADING.INTERNALS
@ -247,6 +247,7 @@ PHP 8.4 INTERNALS UPGRADE NOTES
   - Removed the "properties" HashTable field from php_libxml_node_object.
   - Added a way to attached private data to a php_libxml_ref_obj.
   - Added a way to fix a class type onto php_libxml_ref_obj.
+   - Added a way to record quirks mode in php_libxml_ref_obj.
   - Added php_libxml_uses_internal_errors().
   - Added a way to override document handlers (e.g. serialization) with
     php_libxml_document_handlers.
--- a/codecov.yml
+++ b/codecov.yml
@ -1,3 +1,11 @@
 ignore:
-  - "ext/dom/lexbor/lexbor" # bundled library
-  - "ext/pcre/pcre2lib" # bundled library
+  # bundled libraries
+  - "ext/dom/lexbor/lexbor/core"
+  - "ext/dom/lexbor/lexbor/css"
+  - "ext/dom/lexbor/lexbor/dom"
+  - "ext/dom/lexbor/lexbor/encoding"
+  - "ext/dom/lexbor/lexbor/html"
+  - "ext/dom/lexbor/lexbor/ns"
+  - "ext/dom/lexbor/lexbor/ports"
+  - "ext/dom/lexbor/lexbor/tag"
+  - "ext/pcre/pcre2lib"
--- a/ext/dom/config.m4
+++ b/ext/dom/config.m4
@ -22,12 +22,14 @@ if test "$PHP_DOM" != "no"; then
      $LEXBOR_DIR/encoding/big5.c $LEXBOR_DIR/encoding/decode.c $LEXBOR_DIR/encoding/encode.c $LEXBOR_DIR/encoding/encoding.c $LEXBOR_DIR/encoding/euc_kr.c $LEXBOR_DIR/encoding/gb18030.c $LEXBOR_DIR/encoding/iso_2022_jp_katakana.c $LEXBOR_DIR/encoding/jis0208.c $LEXBOR_DIR/encoding/jis0212.c $LEXBOR_DIR/encoding/range.c $LEXBOR_DIR/encoding/res.c $LEXBOR_DIR/encoding/single.c \
      $LEXBOR_DIR/html/encoding.c $LEXBOR_DIR/html/interface.c $LEXBOR_DIR/html/parser.c $LEXBOR_DIR/html/token.c $LEXBOR_DIR/html/token_attr.c $LEXBOR_DIR/html/tokenizer.c $LEXBOR_DIR/html/tree.c \
      $LEXBOR_DIR/html/interfaces/anchor_element.c $LEXBOR_DIR/html/interfaces/area_element.c $LEXBOR_DIR/html/interfaces/audio_element.c $LEXBOR_DIR/html/interfaces/base_element.c $LEXBOR_DIR/html/interfaces/body_element.c $LEXBOR_DIR/html/interfaces/br_element.c $LEXBOR_DIR/html/interfaces/button_element.c $LEXBOR_DIR/html/interfaces/canvas_element.c $LEXBOR_DIR/html/interfaces/data_element.c $LEXBOR_DIR/html/interfaces/data_list_element.c $LEXBOR_DIR/html/interfaces/details_element.c $LEXBOR_DIR/html/interfaces/dialog_element.c $LEXBOR_DIR/html/interfaces/directory_element.c $LEXBOR_DIR/html/interfaces/div_element.c $LEXBOR_DIR/html/interfaces/d_list_element.c $LEXBOR_DIR/html/interfaces/document.c $LEXBOR_DIR/html/interfaces/element.c $LEXBOR_DIR/html/interfaces/embed_element.c $LEXBOR_DIR/html/interfaces/field_set_element.c $LEXBOR_DIR/html/interfaces/font_element.c $LEXBOR_DIR/html/interfaces/form_element.c $LEXBOR_DIR/html/interfaces/frame_element.c $LEXBOR_DIR/html/interfaces/frame_set_element.c $LEXBOR_DIR/html/interfaces/head_element.c $LEXBOR_DIR/html/interfaces/heading_element.c $LEXBOR_DIR/html/interfaces/hr_element.c $LEXBOR_DIR/html/interfaces/html_element.c $LEXBOR_DIR/html/interfaces/iframe_element.c $LEXBOR_DIR/html/interfaces/image_element.c $LEXBOR_DIR/html/interfaces/input_element.c $LEXBOR_DIR/html/interfaces/label_element.c $LEXBOR_DIR/html/interfaces/legend_element.c $LEXBOR_DIR/html/interfaces/li_element.c $LEXBOR_DIR/html/interfaces/link_element.c $LEXBOR_DIR/html/interfaces/map_element.c $LEXBOR_DIR/html/interfaces/marquee_element.c $LEXBOR_DIR/html/interfaces/media_element.c $LEXBOR_DIR/html/interfaces/menu_element.c $LEXBOR_DIR/html/interfaces/meta_element.c $LEXBOR_DIR/html/interfaces/meter_element.c $LEXBOR_DIR/html/interfaces/mod_element.c $LEXBOR_DIR/html/interfaces/object_element.c $LEXBOR_DIR/html/interfaces/o_list_element.c $LEXBOR_DIR/html/interfaces/opt_group_element.c $LEXBOR_DIR/html/interfaces/option_element.c $LEXBOR_DIR/html/interfaces/output_element.c $LEXBOR_DIR/html/interfaces/paragraph_element.c $LEXBOR_DIR/html/interfaces/param_element.c $LEXBOR_DIR/html/interfaces/picture_element.c $LEXBOR_DIR/html/interfaces/pre_element.c $LEXBOR_DIR/html/interfaces/progress_element.c $LEXBOR_DIR/html/interfaces/quote_element.c $LEXBOR_DIR/html/interfaces/script_element.c $LEXBOR_DIR/html/interfaces/select_element.c $LEXBOR_DIR/html/interfaces/slot_element.c $LEXBOR_DIR/html/interfaces/source_element.c $LEXBOR_DIR/html/interfaces/span_element.c $LEXBOR_DIR/html/interfaces/style_element.c $LEXBOR_DIR/html/interfaces/table_caption_element.c $LEXBOR_DIR/html/interfaces/table_cell_element.c $LEXBOR_DIR/html/interfaces/table_col_element.c $LEXBOR_DIR/html/interfaces/table_element.c $LEXBOR_DIR/html/interfaces/table_row_element.c $LEXBOR_DIR/html/interfaces/table_section_element.c $LEXBOR_DIR/html/interfaces/template_element.c $LEXBOR_DIR/html/interfaces/text_area_element.c $LEXBOR_DIR/html/interfaces/time_element.c $LEXBOR_DIR/html/interfaces/title_element.c $LEXBOR_DIR/html/interfaces/track_element.c $LEXBOR_DIR/html/interfaces/u_list_element.c $LEXBOR_DIR/html/interfaces/unknown_element.c $LEXBOR_DIR/html/interfaces/video_element.c $LEXBOR_DIR/html/interfaces/window.c \
-      $LEXBOR_DIR/selectors/selectors.c \
+      $LEXBOR_DIR/css/state.c $LEXBOR_DIR/css/log.c $LEXBOR_DIR/css/parser.c $LEXBOR_DIR/css/selectors/state.c $LEXBOR_DIR/css/selectors/selectors.c $LEXBOR_DIR/css/selectors/selector.c $LEXBOR_DIR/css/selectors/pseudo_state.c $LEXBOR_DIR/css/selectors/pseudo.c $LEXBOR_DIR/css/syntax/tokenizer/error.c $LEXBOR_DIR/css/syntax/state.c $LEXBOR_DIR/css/syntax/parser.c $LEXBOR_DIR/css/syntax/syntax.c $LEXBOR_DIR/css/syntax/anb.c $LEXBOR_DIR/css/syntax/tokenizer.c $LEXBOR_DIR/css/syntax/token.c $LEXBOR_DIR/css/css.c \
+      $LEXBOR_DIR/selectors-adapted/selectors.c \
      $LEXBOR_DIR/ns/ns.c \
      $LEXBOR_DIR/tag/tag.c"
    PHP_NEW_EXTENSION(dom, [php_dom.c attr.c document.c infra.c \
                            xml_document.c html_document.c xml_serializer.c html5_serializer.c html5_parser.c namespace_compat.c \
-                            domexception.c parentnode.c \
+                            domexception.c \
+                            parentnode/tree.c parentnode/css_selectors.c \
                            processinginstruction.c cdatasection.c \
                            documentfragment.c domimplementation.c \
                            element.c node.c characterdata.c \
@ -38,6 +40,7 @@ if test "$PHP_DOM" != "no"; then
                            namednodemap.c xpath_callbacks.c \
                            $LEXBOR_SOURCES],
                            $ext_shared,,$PHP_LEXBOR_CFLAGS)
+    PHP_ADD_BUILD_DIR($ext_builddir/parentnode)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/ports/posix/lexbor/core)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/core)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/dom/interfaces)
@ -45,7 +48,10 @@ if test "$PHP_DOM" != "no"; then
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/html/tokenizer)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/html/interfaces)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/encoding)
-    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/selectors)
+    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/css/selectors)
+    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/css/tokenizer)
+    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/css/syntax/tokenizer)
+    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/selectors-adapted)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/ns)
    PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/tag)
    PHP_SUBST(DOM_SHARED_LIBADD)
--- a/ext/dom/config.w32
+++ b/ext/dom/config.w32
@ -9,7 +9,7 @@ if (PHP_DOM == "yes") {
 	) {
 		EXTENSION("dom", "php_dom.c attr.c document.c infra.c \
 			xml_document.c html_document.c xml_serializer.c html5_serializer.c html5_parser.c namespace_compat.c \
-			domexception.c parentnode.c processinginstruction.c \
+			domexception.c processinginstruction.c \
 			cdatasection.c documentfragment.c domimplementation.c element.c \
 			node.c characterdata.c documenttype.c \
 			entity.c nodelist.c html_collection.c text.c comment.c \
@ -17,6 +17,7 @@ if (PHP_DOM == "yes") {
 			notation.c xpath.c dom_iterators.c \
 			namednodemap.c xpath_callbacks.c", null, "-Iext/dom/lexbor");

+		ADD_SOURCES("ext/dom/parentnode", "tree.c css_selectors.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/ports/windows_nt/lexbor/core", "memory.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/core", "array_obj.c array.c avl.c bst.c diyfp.c conv.c dobject.c dtoa.c hash.c mem.c mraw.c print.c serialize.c shs.c str.c strtod.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/dom", "interface.c", "dom");
@ -27,7 +28,11 @@ if (PHP_DOM == "yes") {
 		ADD_SOURCES("ext/dom/lexbor/lexbor/html", "encoding.c interface.c parser.c token.c token_attr.c tokenizer.c tree.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/encoding", "big5.c decode.c encode.c encoding.c euc_kr.c gb18030.c iso_2022_jp_katakana.c jis0208.c jis0212.c range.c res.c single.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/html/interfaces", "anchor_element.c area_element.c audio_element.c base_element.c body_element.c br_element.c button_element.c canvas_element.c data_element.c data_list_element.c details_element.c dialog_element.c directory_element.c div_element.c d_list_element.c document.c element.c embed_element.c field_set_element.c font_element.c form_element.c frame_element.c frame_set_element.c head_element.c heading_element.c hr_element.c html_element.c iframe_element.c image_element.c input_element.c label_element.c legend_element.c li_element.c link_element.c map_element.c marquee_element.c media_element.c menu_element.c meta_element.c meter_element.c mod_element.c object_element.c o_list_element.c opt_group_element.c option_element.c output_element.c paragraph_element.c param_element.c picture_element.c pre_element.c progress_element.c quote_element.c script_element.c select_element.c slot_element.c source_element.c span_element.c style_element.c table_caption_element.c table_cell_element.c table_col_element.c table_element.c table_row_element.c table_section_element.c template_element.c text_area_element.c time_element.c title_element.c track_element.c u_list_element.c unknown_element.c video_element.c window.c", "dom");
-		ADD_SOURCES("ext/dom/lexbor/lexbor/selectors", "selectors.c", "dom");
+		ADD_SOURCES("ext/dom/lexbor/lexbor/selectors-adapted", "selectors.c", "dom");
+		ADD_SOURCES("ext/dom/lexbor/lexbor/css", "state.c log.c parser.c css.c", "dom");
+		ADD_SOURCES("ext/dom/lexbor/lexbor/css/selectors", "state.c selectors.c selector.c pseudo_state.c pseudo.c", "dom");
+		ADD_SOURCES("ext/dom/lexbor/lexbor/css/syntax", "state.c parser.c syntax.c anb.c tokenizer.c token.c", "dom");
+		ADD_SOURCES("ext/dom/lexbor/lexbor/css/syntax/tokenizer", "error.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/ns", "ns.c", "dom");
 		ADD_SOURCES("ext/dom/lexbor/lexbor/tag", "tag.c", "dom");
 		ADD_FLAG("CFLAGS_DOM", "/D LEXBOR_STATIC ");
--- a/ext/dom/domexception.h
+++ b/ext/dom/domexception.h
@ -46,4 +46,7 @@ typedef enum {
 	VALIDATION_ERR                 = 16
 } dom_exception_code;

+void php_dom_throw_error(dom_exception_code error_code, bool strict_error);
+void php_dom_throw_error_with_message(dom_exception_code error_code, const char *error_message, bool strict_error);
+
 #endif /* DOM_EXCEPTION_H */
--- a/ext/dom/element.c
+++ b/ext/dom/element.c
@ -1752,4 +1752,66 @@ out:
 }
 /* }}} end DOMElement::prepend */

+static void php_dom_dispatch_query_selector(INTERNAL_FUNCTION_PARAMETERS, bool all)
+{
+	zend_string *selectors_str;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_STR(selectors_str)
+	ZEND_PARSE_PARAMETERS_END();
+
+	xmlNodePtr thisp;
+	dom_object *intern;
+	zval *id;
+	DOM_GET_THIS_OBJ(thisp, id, xmlNodePtr, intern);
+
+	if (all) {
+		dom_parent_node_query_selector_all(thisp, intern, return_value, selectors_str);
+	} else {
+		dom_parent_node_query_selector(thisp, intern, return_value, selectors_str);
+	}
+}
+
+PHP_METHOD(Dom_Element, querySelector)
+{
+	php_dom_dispatch_query_selector(INTERNAL_FUNCTION_PARAM_PASSTHRU, false);
+}
+
+PHP_METHOD(Dom_Element, querySelectorAll)
+{
+	php_dom_dispatch_query_selector(INTERNAL_FUNCTION_PARAM_PASSTHRU, true);
+}
+
+PHP_METHOD(Dom_Element, matches)
+{
+	zend_string *selectors_str;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_STR(selectors_str)
+	ZEND_PARSE_PARAMETERS_END();
+
+	xmlNodePtr thisp;
+	dom_object *intern;
+	zval *id;
+	DOM_GET_THIS_OBJ(thisp, id, xmlNodePtr, intern);
+
+	dom_element_matches(thisp, intern, return_value, selectors_str);
+}
+
+PHP_METHOD(Dom_Element, closest)
+{
+	zend_string *selectors_str;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_STR(selectors_str)
+	ZEND_PARSE_PARAMETERS_END();
+
+	xmlNodePtr thisp;
+	dom_object *intern;
+	zval *id;
+	DOM_GET_THIS_OBJ(thisp, id, xmlNodePtr, intern);
+
+	dom_element_closest(thisp, intern, return_value, selectors_str);
+}
+
 #endif
--- a/ext/dom/html5_parser.c
+++ b/ext/dom/html5_parser.c
@ -24,6 +24,7 @@
 #include "html5_parser.h"
 #include <lexbor/html/parser.h>
 #include <lexbor/html/interfaces/element.h>
+#include <lexbor/dom/dom.h>
 #include <libxml/parserInternals.h>
 #include <libxml/HTMLtree.h>
 #include <Zend/zend.h>
@ -380,6 +381,7 @@ void lexbor_libxml2_bridge_copy_observations(lxb_html_tree_t *tree, lexbor_libxm
    observations->has_explicit_html_tag = tree->has_explicit_html_tag;
    observations->has_explicit_head_tag = tree->has_explicit_head_tag;
    observations->has_explicit_body_tag = tree->has_explicit_body_tag;
+    observations->quirks_mode = lxb_dom_interface_document(tree->document)->compat_mode == LXB_DOM_DOCUMENT_CMODE_QUIRKS;
 }

 #endif  /* HAVE_LIBXML && HAVE_DOM */
--- a/ext/dom/html5_parser.h
+++ b/ext/dom/html5_parser.h
@ -47,6 +47,7 @@ typedef struct _lexbor_libxml2_bridge_extracted_observations {
    bool has_explicit_html_tag;
    bool has_explicit_head_tag;
    bool has_explicit_body_tag;
+    bool quirks_mode;
 } lexbor_libxml2_bridge_extracted_observations;

 typedef struct _lexbor_libxml2_bridge_parse_context {
--- a/ext/dom/html_document.c
+++ b/ext/dom/html_document.c
@ -917,6 +917,7 @@ PHP_METHOD(Dom_HTMLDocument, createFromString)
 		NULL
 	);
 	dom_set_xml_class(intern->document);
+	intern->document->quirks_mode = ctx.observations.quirks_mode;
 	intern->document->private_data = php_dom_libxml_ns_mapper_header(ns_mapper);
 	return;

@ -1137,6 +1138,7 @@ PHP_METHOD(Dom_HTMLDocument, createFromFile)
 		NULL
 	);
 	dom_set_xml_class(intern->document);
+	intern->document->quirks_mode = ctx.observations.quirks_mode;
 	intern->document->private_data = php_dom_libxml_ns_mapper_header(ns_mapper);
 	return;

--- a/ext/dom/lexbor/lexbor/selectors-adapted/selectors.c
+++ b/ext/dom/lexbor/lexbor/selectors-adapted/selectors.c
--- a/ext/dom/lexbor/lexbor/selectors-adapted/selectors.h
+++ b/ext/dom/lexbor/lexbor/selectors-adapted/selectors.h
@ -0,0 +1,254 @@
+/*
+ * Copyright (C) 2021-2024 Alexander Borisov
+ *
+ * Author: Alexander Borisov <borisov@lexbor.com>
+ * Adapted for PHP libxml2 by: Niels Dossche <nielsdos@php.net>
+ */
+
+
+#ifndef LEXBOR_SELECTORS_H
+#define LEXBOR_SELECTORS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "lexbor/selectors/base.h"
+#include "lexbor/dom/dom.h"
+#include "lexbor/css/selectors/selectors.h"
+#include "lexbor/core/array_obj.h"
+#include <libxml/tree.h>
+
+
+typedef enum {
+	LXB_SELECTORS_OPT_DEFAULT = 0x00,
+
+	/*
+	 * Includes the passed (root) node in the search.
+	 *
+	 * By default, the root node does not participate in selector searches,
+	 * only its children.
+	 *
+	 * This behavior is logical, if you have found a node and then you want to
+	 * search for other nodes in it, you don't need to check it again.
+	 *
+	 * But there are cases when it is necessary for root node to participate
+	 * in the search.  That's what this option is for.
+	 */
+	LXB_SELECTORS_OPT_MATCH_ROOT = 1 << 1,
+
+	/*
+	 * Stop searching after the first match with any of the selectors
+	 * in the list.
+	 *
+	 * By default, the callback will be triggered for each selector list.
+	 * That is, if your node matches different selector lists, it will be
+	 * returned multiple times in the callback.
+	 *
+	 * For example:
+	 *    HTML: <div id="ok"><span>test</span></div>
+	 *    Selectors: div, div[id="ok"], div:has(:not(a))
+	 *
+	 * The default behavior will cause three callbacks with the same node (div).
+	 * Because it will be found by every selector in the list.
+	 *
+	 * This option allows you to end the element check after the first match on
+	 * any of the selectors.  That is, the callback will be called only once
+	 * for example above.  This way we get rid of duplicates in the search.
+	 */
+	LXB_SELECTORS_OPT_MATCH_FIRST = 1 << 2,
+
+	/* Quirks mode (sigh) */
+	LXB_SELECTORS_OPT_QUIRKS_MODE = 1 << 3,
+}
+lxb_selectors_opt_t;
+
+typedef struct lxb_selectors lxb_selectors_t;
+typedef struct lxb_selectors_entry lxb_selectors_entry_t;
+typedef struct lxb_selectors_nested lxb_selectors_nested_t;
+
+typedef lxb_status_t
+(*lxb_selectors_cb_f)(const xmlNode *node,
+					  lxb_css_selector_specificity_t spec, void *ctx);
+
+typedef lxb_selectors_entry_t *
+(*lxb_selectors_state_cb_f)(lxb_selectors_t *selectors,
+							lxb_selectors_entry_t *entry);
+
+typedef struct {
+	const xmlChar *name;
+	bool interned;
+} lxb_selectors_adapted_id;
+
+struct lxb_selectors_entry {
+	lxb_selectors_adapted_id      id;
+	lxb_css_selector_combinator_t combinator;
+	const lxb_css_selector_t      *selector;
+	const xmlNode                 *node;
+	lxb_selectors_entry_t         *next;
+	lxb_selectors_entry_t         *prev;
+	lxb_selectors_entry_t         *following;
+	lxb_selectors_nested_t        *nested;
+};
+
+struct lxb_selectors_nested {
+	lxb_selectors_entry_t    *entry;
+	lxb_selectors_state_cb_f return_state;
+
+	lxb_selectors_cb_f       cb;
+	void                     *ctx;
+
+	const xmlNode            *root;
+	lxb_selectors_entry_t    *last;
+	lxb_selectors_nested_t   *parent;
+
+	size_t                   index;
+	bool                     found;
+};
+
+struct lxb_selectors {
+	lxb_selectors_state_cb_f state;
+	lexbor_dobject_t         *objs;
+	lexbor_dobject_t         *nested;
+
+	lxb_selectors_nested_t   *current;
+	lxb_selectors_entry_t    *first;
+
+	lxb_selectors_opt_t      options;
+	lxb_status_t             status;
+};
+
+
+/*
+ * Initialization of lxb_selectors_t object.
+ *
+ * Caches are initialized in this function.
+ *
+ * @param[in] lxb_selectors_t *
+ *
+ * @return LXB_STATUS_OK if successful, otherwise an error status value.
+ */
+LXB_API lxb_status_t
+lxb_selectors_init(lxb_selectors_t *selectors);
+
+/*
+ * Clears the object. Returns object to states as after initialization.
+ *
+ * After each call to lxb_selectors_find() and lxb_selectors_find_for_node(),
+ * the lxb_selectors_t object is cleared. That is, you don't need to call this
+ * function every time after searching by a selector.
+ *
+ * @param[in] lxb_url_parser_t *
+ */
+LXB_API void
+lxb_selectors_clean(lxb_selectors_t *selectors);
+
+/*
+ * Destroy lxb_selectors_t object.
+ *
+ * Destroying all caches.
+ *
+ * @param[in] lxb_selectors_t *. Can be NULL.
+ * if true: destroys the lxb_selectors_t object and all internal caches.
+ */
+LXB_API void
+lxb_selectors_destroy(lxb_selectors_t *selectors);
+
+/*
+ * Search for nodes by selector list.
+ *
+ * Default Behavior:
+ *    1. The root node does not participate in the search, only its child nodes.
+ *    2. If a node matches multiple selector lists, a callback with that node
+ *       will be called on each list.
+ *       For example:
+ *           HTML: <div id="ok"><span></span></div>
+ *           Selectors: div, div[id="ok"], div:has(:not(a))
+ *       For each selector list, a callback with a "div" node will be called.
+ *
+ * To change the search behavior, see lxb_selectors_opt_set().
+ *
+ * @param[in] lxb_selectors_t *.
+ * @param[in] const xmlNode *.  The node from which the search will begin.
+ * @param[in] const lxb_css_selector_list_t *.  Selectors List.
+ * @param[in] lxb_selectors_cb_f.  Callback for a found node.
+ * @param[in] void *.  Context for the callback.
+ * if true: destroys the lxb_selectors_t object and all internal caches.
+ *
+ * @return LXB_STATUS_OK if successful, otherwise an error status value.
+ */
+LXB_API lxb_status_t
+lxb_selectors_find(lxb_selectors_t *selectors, const xmlNode *root,
+				   const lxb_css_selector_list_t *list,
+				   lxb_selectors_cb_f cb, void *ctx);
+
+/*
+ * Match a node to a Selectors List.
+ *
+ * In other words, the function checks which selector lists will find the
+ * specified node.
+ *
+ * Default Behavior:
+ *    1. If a node matches multiple selector lists, a callback with that node
+ *       will be called on each list.
+ *       For example:
+ *           HTML: <div id="ok"><span></span></div>
+ *           Node: div
+ *           Selectors: div, div[id="ok"], div:has(:not(a))
+ *       For each selector list, a callback with a "div" node will be called.
+ *
+ * To change the search behavior, see lxb_selectors_opt_set().
+ *
+ * @param[in] lxb_selectors_t *.
+ * @param[in] const xmlNode *.  The node from which the search will begin.
+ * @param[in] const lxb_css_selector_list_t *.  Selectors List.
+ * @param[in] lxb_selectors_cb_f.  Callback for a found node.
+ * @param[in] void *.  Context for the callback.
+ * if true: destroys the lxb_selectors_t object and all internal caches.
+ *
+ * @return LXB_STATUS_OK if successful, otherwise an error status value.
+ */
+LXB_API lxb_status_t
+lxb_selectors_match_node(lxb_selectors_t *selectors, const xmlNode *node,
+						 const lxb_css_selector_list_t *list,
+						 lxb_selectors_cb_f cb, void *ctx);
+
+/*
+ * Inline functions.
+ */
+
+/*
+ * The function sets the node search options.
+ *
+ * For more information, see lxb_selectors_opt_t.
+ *
+ * @param[in] lxb_selectors_t *.
+ * @param[in] lxb_selectors_opt_t.
+ */
+lxb_inline void
+lxb_selectors_opt_set(lxb_selectors_t *selectors, lxb_selectors_opt_t opt)
+{
+	selectors->options = opt;
+}
+
+/*
+ * Get the current selector.
+ *
+ * Function to get the selector by which the node was found.
+ * Use context (void *ctx) to pass the lxb_selectors_t object to the callback.
+ *
+ * @param[in] const lxb_selectors_t *.
+ *
+ * @return const lxb_css_selector_list_t *.
+ */
+lxb_inline const lxb_css_selector_list_t *
+lxb_selectors_selector(const lxb_selectors_t *selectors)
+{
+	return selectors->current->entry->selector->list;
+}
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* LEXBOR_SELECTORS_H */
--- a/ext/dom/parentnode/css_selectors.c
+++ b/ext/dom/parentnode/css_selectors.c
@ -0,0 +1,282 @@
+/*
+   +----------------------------------------------------------------------+
+   | Copyright (c) The PHP Group                                          |
+   +----------------------------------------------------------------------+
+   | This source file is subject to version 3.01 of the PHP license,      |
+   | that is bundled with this package in the file LICENSE, and is        |
+   | available through the world-wide-web at the following url:           |
+   | https://www.php.net/license/3_01.txt                                 |
+   | If you did not receive a copy of the PHP license and are unable to   |
+   | obtain it through the world-wide-web, please send a note to          |
+   | license@php.net so we can mail you a copy immediately.               |
+   +----------------------------------------------------------------------+
+   | Authors: Niels Dossche <nielsdos@php.net>                            |
+   +----------------------------------------------------------------------+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "php.h"
+#if defined(HAVE_LIBXML) && defined(HAVE_DOM)
+#include "../php_dom.h"
+
+#include "lexbor/css/parser.h"
+#include "lexbor/selectors-adapted/selectors.h"
+
+// TODO: optimization idea: cache the parsed selectors in an LRU fashion?
+
+typedef struct {
+	HashTable *list;
+	dom_object *intern;
+} dom_query_selector_all_ctx;
+
+typedef struct {
+	const xmlNode *reference;
+	bool result;
+} dom_query_selector_matches_ctx;
+
+static lxb_selectors_opt_t dom_quirks_opt(lxb_selectors_opt_t options, const dom_object *intern)
+{
+	if (intern->document != NULL && intern->document->quirks_mode) {
+		options |= LXB_SELECTORS_OPT_QUIRKS_MODE;
+	}
+	return options;
+}
+
+lxb_status_t dom_query_selector_find_single_callback(const xmlNode *node, lxb_css_selector_specificity_t spec, void *ctx)
+{
+	xmlNodePtr *result = (xmlNodePtr *) ctx;
+	*result = (xmlNodePtr) node;
+	return LXB_STATUS_STOP;
+}
+
+lxb_status_t dom_query_selector_find_array_callback(const xmlNode *node, lxb_css_selector_specificity_t spec, void *ctx)
+{
+	dom_query_selector_all_ctx *qsa_ctx = (dom_query_selector_all_ctx *) ctx;
+	zval object;
+	php_dom_create_object((xmlNodePtr) node, &object, qsa_ctx->intern);
+	zend_hash_next_index_insert_new(qsa_ctx->list, &object);
+	return LXB_STATUS_OK;
+}
+
+lxb_status_t dom_query_selector_find_matches_callback(const xmlNode *node, lxb_css_selector_specificity_t spec, void *ctx)
+{
+	dom_query_selector_matches_ctx *matches_ctx = (dom_query_selector_matches_ctx *) ctx;
+	if (node == matches_ctx->reference) {
+		matches_ctx->result = true;
+		return LXB_STATUS_STOP;
+	}
+	return LXB_STATUS_OK;
+}
+
+static lxb_css_selector_list_t *dom_parse_selector(
+	lxb_css_parser_t *parser,
+	lxb_selectors_t *selectors,
+	const zend_string *selectors_str,
+	lxb_selectors_opt_t options,
+	const dom_object *intern
+)
+{
+	lxb_status_t status;
+
+	memset(parser, 0, sizeof(lxb_css_parser_t));
+	status = lxb_css_parser_init(parser, NULL);
+	ZEND_ASSERT(status == LXB_STATUS_OK);
+
+	memset(selectors, 0, sizeof(lxb_selectors_t));
+	status = lxb_selectors_init(selectors);
+	ZEND_ASSERT(status == LXB_STATUS_OK);
+	lxb_selectors_opt_set(selectors, dom_quirks_opt(options, intern));
+
+	lxb_css_selector_list_t *list = lxb_css_selectors_parse(parser, (const lxb_char_t *) ZSTR_VAL(selectors_str), ZSTR_LEN(selectors_str));
+	if (UNEXPECTED(list == NULL)) {
+		size_t nr_of_messages = lexbor_array_obj_length(&parser->log->messages);
+		if (nr_of_messages > 0) {
+			lxb_css_log_message_t *msg = lexbor_array_obj_get(&parser->log->messages, 0);
+			char *error;
+			zend_spprintf(&error, 0, "Invalid selector (%.*s)", (int) msg->text.length, msg->text.data);
+			php_dom_throw_error_with_message(SYNTAX_ERR, error, true);
+			efree(error);
+		} else {
+			php_dom_throw_error_with_message(SYNTAX_ERR, "Invalid selector", true);
+		}
+	}
+	
+	return list;
+}
+
+static lxb_status_t dom_check_css_execution_status(lxb_status_t status)
+{
+	if (UNEXPECTED(status != LXB_STATUS_OK && status != LXB_STATUS_STOP)) {
+		zend_argument_value_error(1, "contains an unsupported selector");
+		return status;
+	}
+	return LXB_STATUS_OK;
+}
+
+static void dom_selector_cleanup(lxb_css_parser_t *parser, lxb_selectors_t *selectors, lxb_css_selector_list_t *list)
+{
+	lxb_css_selector_list_destroy_memory(list);
+	lxb_selectors_destroy(selectors);
+	(void) lxb_css_parser_destroy(parser, false);
+}
+
+static lxb_status_t dom_query_selector_common(
+	const xmlNode *root,
+	const dom_object *intern,
+	const zend_string *selectors_str,
+	lxb_selectors_cb_f cb,
+	void *ctx,
+	lxb_selectors_opt_t options
+)
+{
+	lxb_status_t status;
+
+	lxb_css_parser_t parser;
+	lxb_selectors_t selectors;
+
+	lxb_css_selector_list_t *list = dom_parse_selector(&parser, &selectors, selectors_str, options, intern);
+	if (UNEXPECTED(list == NULL)) {
+		status = LXB_STATUS_ERROR;
+	} else {
+		status = lxb_selectors_find(&selectors, root, list, cb, ctx);
+		status = dom_check_css_execution_status(status);
+	}
+
+	dom_selector_cleanup(&parser, &selectors, list);
+
+	return status;
+}
+
+static lxb_status_t dom_query_matches(
+	const xmlNode *root,
+	const dom_object *intern,
+	const zend_string *selectors_str,
+	void *ctx
+)
+{
+	lxb_status_t status;
+
+	lxb_css_parser_t parser;
+	lxb_selectors_t selectors;
+
+	lxb_css_selector_list_t *list = dom_parse_selector(&parser, &selectors, selectors_str, LXB_SELECTORS_OPT_MATCH_FIRST, intern);
+	if (UNEXPECTED(list == NULL)) {
+		status = LXB_STATUS_ERROR;
+	} else {
+		status = lxb_selectors_match_node(&selectors, root, list, dom_query_selector_find_matches_callback, ctx);
+		status = dom_check_css_execution_status(status);
+	}
+
+	dom_selector_cleanup(&parser, &selectors, list);
+
+	return status;
+}
+
+static const xmlNode *dom_query_closest(
+	const xmlNode *root,
+	const dom_object *intern,
+	const zend_string *selectors_str
+)
+{
+	const xmlNode *ret = NULL;
+
+	lxb_css_parser_t parser;
+	lxb_selectors_t selectors;
+
+	lxb_css_selector_list_t *list = dom_parse_selector(&parser, &selectors, selectors_str, LXB_SELECTORS_OPT_MATCH_FIRST, intern);
+	if (EXPECTED(list != NULL)) {
+		const xmlNode *current = root;
+		while (current != NULL) {
+			dom_query_selector_matches_ctx ctx = { current, false };
+			lxb_status_t status = lxb_selectors_match_node(&selectors, current, list, dom_query_selector_find_matches_callback, &ctx);
+			status = dom_check_css_execution_status(status);
+			if (UNEXPECTED(status != LXB_STATUS_OK)) {
+				break;
+			}
+			if (ctx.result) {
+				ret = current;
+				break;
+			}
+			current = current->parent;
+		}
+	}
+
+	dom_selector_cleanup(&parser, &selectors, list);
+
+	return ret;
+}
+
+/* https://dom.spec.whatwg.org/#dom-parentnode-queryselector */
+void dom_parent_node_query_selector(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str)
+{
+	xmlNodePtr result = NULL;
+
+	if (dom_query_selector_common(
+		thisp,
+		intern,
+		selectors_str,
+		dom_query_selector_find_single_callback,
+		&result,
+		LXB_SELECTORS_OPT_MATCH_FIRST
+	) != LXB_STATUS_OK || result == NULL) {
+		RETURN_NULL();
+	} else {
+		DOM_RET_OBJ(result, intern);
+	}
+}
+
+/* https://dom.spec.whatwg.org/#dom-parentnode-queryselectorall */
+void dom_parent_node_query_selector_all(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str)
+{
+	HashTable *list = zend_new_array(0);
+	dom_query_selector_all_ctx ctx = { list, intern };
+
+	if (dom_query_selector_common(
+		thisp,
+		intern,
+		selectors_str,
+		dom_query_selector_find_array_callback,
+		&ctx,
+		LXB_SELECTORS_OPT_DEFAULT
+	) != LXB_STATUS_OK) {
+		zend_array_destroy(list);
+		RETURN_THROWS();
+	} else {
+		php_dom_create_iterator(return_value, DOM_NODELIST, true);
+		dom_object *ret_obj = Z_DOMOBJ_P(return_value);
+		dom_nnodemap_object *mapptr = (dom_nnodemap_object *) ret_obj->ptr;
+		ZVAL_ARR(&mapptr->baseobj_zv, list);
+		mapptr->nodetype = DOM_NODESET;
+	}
+}
+
+/* https://dom.spec.whatwg.org/#dom-element-matches */
+void dom_element_matches(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str)
+{
+	dom_query_selector_matches_ctx ctx = { thisp, false };
+
+	if (dom_query_matches(
+		thisp,
+		intern,
+		selectors_str,
+		&ctx
+	) != LXB_STATUS_OK) {
+		RETURN_THROWS();
+	} else {
+		RETURN_BOOL(ctx.result);
+	}
+}
+
+/* https://dom.spec.whatwg.org/#dom-element-closest */
+void dom_element_closest(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str)
+{
+	const xmlNode *result = dom_query_closest(thisp, intern, selectors_str);
+	if (EXPECTED(result != NULL)) {
+		DOM_RET_OBJ((xmlNodePtr) result, intern);
+	}
+}
+
+#endif
--- a/ext/dom/parentnode/tree.c
+++ b/ext/dom/parentnode/tree.c
@ -1,6 +1,4 @@
 /*
-   +----------------------------------------------------------------------+
-   | PHP Version 7                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
@ -23,9 +21,9 @@

 #include "php.h"
 #if defined(HAVE_LIBXML) && defined(HAVE_DOM)
-#include "php_dom.h"
-#include "internal_helpers.h"
-#include "dom_properties.h"
+#include "../php_dom.h"
+#include "../internal_helpers.h"
+#include "../dom_properties.h"

 /* {{{ firstElementChild DomParentNode
 readonly=yes
--- a/ext/dom/php_dom.h
+++ b/ext/dom/php_dom.h
@ -130,8 +130,6 @@ zend_object *dom_nnodemap_objects_new(zend_class_entry *class_type);
 zend_object *dom_xpath_objects_new(zend_class_entry *class_type);
 #endif
 bool dom_get_strict_error(php_libxml_ref_obj *document);
-void php_dom_throw_error(dom_exception_code error_code, bool strict_error);
-void php_dom_throw_error_with_message(dom_exception_code error_code, const char *error_message, bool strict_error);
 void node_list_unlink(xmlNodePtr node);
 int dom_check_qname(char *qname, char **localname, char **prefix, int uri_len, int name_len);
 xmlNsPtr dom_get_ns(xmlNodePtr node, char *uri, int *errorcode, char *prefix);
@ -199,6 +197,10 @@ bool php_dom_fragment_insertion_hierarchy_check_replace(xmlNodePtr parent, xmlNo
 void php_dom_node_append(php_libxml_ref_obj *document, xmlNodePtr node, xmlNodePtr parent);
 bool php_dom_pre_insert(php_libxml_ref_obj *document, xmlNodePtr node, xmlNodePtr parent, xmlNodePtr insertion_point);
 bool php_dom_pre_insert_is_parent_invalid(xmlNodePtr parent);
+void dom_parent_node_query_selector(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str);
+void dom_parent_node_query_selector_all(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str);
+void dom_element_matches(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str);
+void dom_element_closest(xmlNodePtr thisp, dom_object *intern, zval *return_value, const zend_string *selectors_str);

 /* nodemap and nodelist APIs */
 xmlNodePtr php_dom_named_node_map_get_named_item(dom_nnodemap_object *objmap, const zend_string *named, bool may_transform);
--- a/ext/dom/php_dom.stub.php
+++ b/ext/dom/php_dom.stub.php
@ -1106,6 +1106,9 @@ namespace Dom
        public function append(Node|string ...$nodes): void;
        public function prepend(Node|string ...$nodes): void;
        public function replaceChildren(Node|string ...$nodes): void;
+
+        public function querySelector(string $selectors): ?Element;
+        public function querySelectorAll(string $selectors): NodeList;
    }

    interface ChildNode
@ -1372,6 +1375,11 @@ namespace Dom
        public function prepend(Node|string ...$nodes): void {}
        /** @implementation-alias DOMElement::replaceChildren */
        public function replaceChildren(Node|string ...$nodes): void {}
+
+        public function querySelector(string $selectors): ?Element {}
+        public function querySelectorAll(string $selectors): NodeList {}
+        public function closest(string $selectors): ?Element {}
+        public function matches(string $selectors): bool {}
    }

    class HTMLElement extends Element
@ -1492,6 +1500,11 @@ namespace Dom
        public function prepend(Node|string ...$nodes): void {}
        /** @implementation-alias DOMElement::replaceChildren */
        public function replaceChildren(Node|string ...$nodes): void {}
+
+        /** @implementation-alias Dom\Element::querySelector */
+        public function querySelector(string $selectors): ?Element {}
+        /** @implementation-alias Dom\Element::querySelectorAll */
+        public function querySelectorAll(string $selectors): NodeList {}
    }

    class Entity extends Node
@ -1585,6 +1598,11 @@ namespace Dom

        public function importLegacyNode(\DOMNode $node, bool $deep = false): Node {}

+        /** @implementation-alias Dom\Element::querySelector */
+        public function querySelector(string $selectors): ?Element {}
+        /** @implementation-alias Dom\Element::querySelectorAll */
+        public function querySelectorAll(string $selectors): NodeList {}
+
        public ?HTMLElement $body;
        /** @readonly */
        public ?HTMLElement $head;
--- a/ext/dom/php_dom_arginfo.h
+++ b/ext/dom/php_dom_arginfo.h
@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: fd650b1e64c4ed4ce66b0dad9c681a51cb8ff1ae */
+ * Stub hash: 28365949d78a2d0254cfdb0da6549e282d2eb436 */

 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_dom_import_simplexml, 0, 1, DOMElement, 0)
 	ZEND_ARG_TYPE_INFO(0, node, IS_OBJECT, 0)
@ -567,6 +567,14 @@ ZEND_END_ARG_INFO()

 #define arginfo_class_Dom_ParentNode_replaceChildren arginfo_class_Dom_ParentNode_append

+ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_Dom_ParentNode_querySelector, 0, 1, Dom\\Element, 1)
+	ZEND_ARG_TYPE_INFO(0, selectors, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_Dom_ParentNode_querySelectorAll, 0, 1, Dom\\\116odeList, 0)
+	ZEND_ARG_TYPE_INFO(0, selectors, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
 #define arginfo_class_Dom_ChildNode_remove arginfo_class_DOMChildNode_remove

 #define arginfo_class_Dom_ChildNode_before arginfo_class_Dom_ParentNode_append
@ -836,6 +844,16 @@ ZEND_END_ARG_INFO()

 #define arginfo_class_Dom_Element_replaceChildren arginfo_class_Dom_ParentNode_append

+#define arginfo_class_Dom_Element_querySelector arginfo_class_Dom_ParentNode_querySelector
+
+#define arginfo_class_Dom_Element_querySelectorAll arginfo_class_Dom_ParentNode_querySelectorAll
+
+#define arginfo_class_Dom_Element_closest arginfo_class_Dom_ParentNode_querySelector
+
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Dom_Element_matches, 0, 1, _IS_BOOL, 0)
+	ZEND_ARG_TYPE_INFO(0, selectors, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
 #define arginfo_class_Dom_Attr_isId arginfo_class_Dom_Node_hasChildNodes

 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Dom_CharacterData_substringData, 0, 2, IS_STRING, 0)
@ -893,6 +911,10 @@ ZEND_END_ARG_INFO()

 #define arginfo_class_Dom_DocumentFragment_replaceChildren arginfo_class_Dom_ParentNode_append

+#define arginfo_class_Dom_DocumentFragment_querySelector arginfo_class_Dom_ParentNode_querySelector
+
+#define arginfo_class_Dom_DocumentFragment_querySelectorAll arginfo_class_Dom_ParentNode_querySelectorAll
+
 #define arginfo_class_Dom_Document_getElementsByTagName arginfo_class_Dom_Element_getElementsByTagName

 #define arginfo_class_Dom_Document_getElementsByTagNameNS arginfo_class_Dom_Element_getElementsByTagNameNS
@ -988,6 +1010,10 @@ ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_Dom_Document_importLegacyNo
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, deep, _IS_BOOL, 0, "false")
 ZEND_END_ARG_INFO()

+#define arginfo_class_Dom_Document_querySelector arginfo_class_Dom_ParentNode_querySelector
+
+#define arginfo_class_Dom_Document_querySelectorAll arginfo_class_Dom_ParentNode_querySelectorAll
+
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_Dom_HTMLDocument_createEmpty, 0, 0, Dom\\HTMLDocument, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, encoding, IS_STRING, 0, "\"UTF-8\"")
 ZEND_END_ARG_INFO()
@ -1272,6 +1298,10 @@ ZEND_METHOD(Dom_Element, getElementsByTagNameNS);
 ZEND_METHOD(Dom_Element, insertAdjacentElement);
 ZEND_METHOD(Dom_Element, insertAdjacentText);
 ZEND_METHOD(Dom_Element, setIdAttributeNode);
+ZEND_METHOD(Dom_Element, querySelector);
+ZEND_METHOD(Dom_Element, querySelectorAll);
+ZEND_METHOD(Dom_Element, closest);
+ZEND_METHOD(Dom_Element, matches);
 ZEND_METHOD(Dom_CharacterData, appendData);
 ZEND_METHOD(Dom_CharacterData, insertData);
 ZEND_METHOD(Dom_CharacterData, deleteData);
@ -1559,6 +1589,8 @@ static const zend_function_entry class_Dom_ParentNode_methods[] = {
 	ZEND_RAW_FENTRY("append", NULL, arginfo_class_Dom_ParentNode_append, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT, NULL, NULL)
 	ZEND_RAW_FENTRY("prepend", NULL, arginfo_class_Dom_ParentNode_prepend, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT, NULL, NULL)
 	ZEND_RAW_FENTRY("replaceChildren", NULL, arginfo_class_Dom_ParentNode_replaceChildren, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT, NULL, NULL)
+	ZEND_RAW_FENTRY("querySelector", NULL, arginfo_class_Dom_ParentNode_querySelector, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT, NULL, NULL)
+	ZEND_RAW_FENTRY("querySelectorAll", NULL, arginfo_class_Dom_ParentNode_querySelectorAll, ZEND_ACC_PUBLIC|ZEND_ACC_ABSTRACT, NULL, NULL)
 	ZEND_FE_END
 };

@ -1671,6 +1703,10 @@ static const zend_function_entry class_Dom_Element_methods[] = {
 	ZEND_RAW_FENTRY("append", zim_DOMElement_append, arginfo_class_Dom_Element_append, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_RAW_FENTRY("prepend", zim_DOMElement_prepend, arginfo_class_Dom_Element_prepend, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_RAW_FENTRY("replaceChildren", zim_DOMElement_replaceChildren, arginfo_class_Dom_Element_replaceChildren, ZEND_ACC_PUBLIC, NULL, NULL)
+	ZEND_ME(Dom_Element, querySelector, arginfo_class_Dom_Element_querySelector, ZEND_ACC_PUBLIC)
+	ZEND_ME(Dom_Element, querySelectorAll, arginfo_class_Dom_Element_querySelectorAll, ZEND_ACC_PUBLIC)
+	ZEND_ME(Dom_Element, closest, arginfo_class_Dom_Element_closest, ZEND_ACC_PUBLIC)
+	ZEND_ME(Dom_Element, matches, arginfo_class_Dom_Element_matches, ZEND_ACC_PUBLIC)
 	ZEND_FE_END
 };

@ -1726,6 +1762,8 @@ static const zend_function_entry class_Dom_DocumentFragment_methods[] = {
 	ZEND_RAW_FENTRY("append", zim_DOMElement_append, arginfo_class_Dom_DocumentFragment_append, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_RAW_FENTRY("prepend", zim_DOMElement_prepend, arginfo_class_Dom_DocumentFragment_prepend, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_RAW_FENTRY("replaceChildren", zim_DOMElement_replaceChildren, arginfo_class_Dom_DocumentFragment_replaceChildren, ZEND_ACC_PUBLIC, NULL, NULL)
+	ZEND_RAW_FENTRY("querySelector", zim_Dom_Element_querySelector, arginfo_class_Dom_DocumentFragment_querySelector, ZEND_ACC_PUBLIC, NULL, NULL)
+	ZEND_RAW_FENTRY("querySelectorAll", zim_Dom_Element_querySelectorAll, arginfo_class_Dom_DocumentFragment_querySelectorAll, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_FE_END
 };

@ -1773,6 +1811,8 @@ static const zend_function_entry class_Dom_Document_methods[] = {
 	ZEND_RAW_FENTRY("prepend", zim_DOMElement_prepend, arginfo_class_Dom_Document_prepend, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_RAW_FENTRY("replaceChildren", zim_DOMDocument_replaceChildren, arginfo_class_Dom_Document_replaceChildren, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_ME(Dom_Document, importLegacyNode, arginfo_class_Dom_Document_importLegacyNode, ZEND_ACC_PUBLIC)
+	ZEND_RAW_FENTRY("querySelector", zim_Dom_Element_querySelector, arginfo_class_Dom_Document_querySelector, ZEND_ACC_PUBLIC, NULL, NULL)
+	ZEND_RAW_FENTRY("querySelectorAll", zim_Dom_Element_querySelectorAll, arginfo_class_Dom_Document_querySelectorAll, ZEND_ACC_PUBLIC, NULL, NULL)
 	ZEND_FE_END
 };

--- a/ext/dom/tests/modern/css_selectors/attribute.phpt
+++ b/ext/dom/tests/modern/css_selectors/attribute.phpt
@ -0,0 +1,118 @@
+--TEST--
+CSS Selectors - Attribute
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <a title="http://example.com" lang="en-us"/>
+    <a title="http://example.be"/>
+    <a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+    <a title="ftp://example.nl" lang="nl-be"/>
+</container>
+XML);
+
+echo "=== Case sensitive ===\n";
+
+test_helper($dom, 'a[title]');
+test_helper($dom, 'a[title="http://example.com"]');
+test_helper($dom, 'a[title="http://example."]');
+test_helper($dom, 'a[title*="example"]');
+test_helper($dom, 'a[title*=""]');
+test_helper($dom, 'a[title^="HTTP"]');
+test_helper($dom, 'a[title^="http"]');
+test_helper($dom, 'a[title^="http"][title$=".be"]');
+test_helper($dom, 'a[title$=".com"]');
+test_helper($dom, 'a[title$=".foo"]');
+test_helper($dom, 'a[lang|="nl"]');
+test_helper($dom, 'a[lang|="nl-be"]');
+test_helper($dom, 'a[tokens~="def"]');
+test_helper($dom, 'a[tokens~="de"]');
+test_helper($dom, 'a[tokens~="def ghi"]');
+
+echo "=== Case insensitive ===\n";
+
+test_helper($dom, 'a[title]');
+test_helper($dom, 'a[title="http://example.COM" i]');
+test_helper($dom, 'a[title="http://EXAMPLE." i]');
+test_helper($dom, 'a[title*="ExAmPlE" i]');
+test_helper($dom, 'a[title^="HTTP" i]');
+test_helper($dom, 'a[title^="HTTP" i][title$=".be"]');
+test_helper($dom, 'a[title$=".COM" i]');
+test_helper($dom, 'a[lang|="NL" i]');
+test_helper($dom, 'a[lang|="NL-BE" i]');
+test_helper($dom, 'a[tokens~="DE" i]');
+test_helper($dom, 'a[tokens~="DEF" i]');
+test_helper($dom, 'a[tokens~="DEF GHI" i]');
+
+?>
+--EXPECT--
+=== Case sensitive ===
+--- Selector: a[title] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[title="http://example.com"] ---
+<a title="http://example.com" lang="en-us"/>
+--- Selector: a[title="http://example."] ---
+--- Selector: a[title*="example"] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[title*=""] ---
+--- Selector: a[title^="HTTP"] ---
+--- Selector: a[title^="http"] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+--- Selector: a[title^="http"][title$=".be"] ---
+<a title="http://example.be"/>
+--- Selector: a[title$=".com"] ---
+<a title="http://example.com" lang="en-us"/>
+--- Selector: a[title$=".foo"] ---
+--- Selector: a[lang|="nl"] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[lang|="nl-be"] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[tokens~="def"] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+--- Selector: a[tokens~="de"] ---
+--- Selector: a[tokens~="def ghi"] ---
+=== Case insensitive ===
+--- Selector: a[title] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[title="http://example.COM" i] ---
+<a title="http://example.com" lang="en-us"/>
+--- Selector: a[title="http://EXAMPLE." i] ---
+--- Selector: a[title*="ExAmPlE" i] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[title^="HTTP" i] ---
+<a title="http://example.com" lang="en-us"/>
+<a title="http://example.be"/>
+--- Selector: a[title^="HTTP" i][title$=".be"] ---
+<a title="http://example.be"/>
+--- Selector: a[title$=".COM" i] ---
+<a title="http://example.com" lang="en-us"/>
+--- Selector: a[lang|="NL" i] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[lang|="NL-BE" i] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+<a title="ftp://example.nl" lang="nl-be"/>
+--- Selector: a[tokens~="DE" i] ---
+--- Selector: a[tokens~="DEF" i] ---
+<a title="ftp://example.be" lang="nl-be" tokens="abc def ghi"/>
+--- Selector: a[tokens~="DEF GHI" i] ---
--- a/ext/dom/tests/modern/css_selectors/closest.phpt
+++ b/ext/dom/tests/modern/css_selectors/closest.phpt
@ -0,0 +1,49 @@
+--TEST--
+Test DOM\Element::closest() method: legit cases
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$xml = <<<XML
+<root>
+  <a/>
+  <div class="foo" xml:id="div1">
+    <div xml:id="div2">
+      <div class="bar" xml:id="div3"/>
+    </div>
+  </div>
+</root>
+XML;
+
+$dom = DOM\XMLDocument::createFromString($xml);
+
+function test($el, $selector) {
+  echo "--- Selector: $selector ---\n";
+  var_dump($el->closest($selector)?->getAttribute('xml:id'));
+}
+
+test($dom->getElementById('div3'), 'div');
+test($dom->getElementById('div3'), '[class="foo"]');
+test($dom->getElementById('div3'), ':not(root)');
+test($dom->getElementById('div3'), ':not(div)');
+test($dom->getElementById('div3'), 'a');
+test($dom->getElementById('div3'), 'root :not(div[class])');
+test($dom->getElementById('div3'), 'root > :not(div[class])');
+
+?>
+--EXPECT--
+--- Selector: div ---
+string(4) "div3"
+--- Selector: [class="foo"] ---
+string(4) "div1"
+--- Selector: :not(root) ---
+string(4) "div3"
+--- Selector: :not(div) ---
+NULL
+--- Selector: a ---
+NULL
+--- Selector: root :not(div[class]) ---
+string(4) "div2"
+--- Selector: root > :not(div[class]) ---
+NULL
--- a/ext/dom/tests/modern/css_selectors/closest_invalid_selector.phpt
+++ b/ext/dom/tests/modern/css_selectors/closest_invalid_selector.phpt
@ -0,0 +1,18 @@
+--TEST--
+Test DOM\Element::closest() method: invalid selector
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = DOM\XMLDocument::createFromString("<root/>");
+
+try {
+  var_dump($dom->documentElement->closest('@invalid'));
+} catch (DOMException $e) {
+  echo $e->getMessage();
+}
+
+?>
+--EXPECT--
+Invalid selector (Selectors. Unexpected token: @invalid)
--- a/ext/dom/tests/modern/css_selectors/combinators.phpt
+++ b/ext/dom/tests/modern/css_selectors/combinators.phpt
@ -0,0 +1,113 @@
+--TEST--
+CSS Selectors - Combinators
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\HTMLDocument::createFromString(<<<HTML
+<!DOCTYPE html>
+<html>
+    <body>
+        <p>First p</p>
+        <p>Second p</p>
+        <img src="1.png">
+        <div class="">
+            <p>Third p</p>
+            <img src="2.png">
+            <img src="3.png">
+            <div class="foo bar baz">
+                <p>Fourth p</p>
+            </div>
+        </div>
+        <article title="foo" class="bar">
+            <p class="bar">Fifth p</p>
+        </article>
+        <table border="1">
+            <colgroup>
+                <col class="selected">
+            </colgroup>
+            <tbody>
+                <tr>
+                    <td>A</td>
+                    <td>B</td>
+                    <td>C</td>
+                </tr>
+            </tbody>
+        </table>
+    </body>
+</html>
+HTML);
+
+test_helper($dom, 'nonsense');
+test_helper($dom, 'p');
+test_helper($dom, 'p, img');
+test_helper($dom, 'body p');
+test_helper($dom, 'body div p');
+test_helper($dom, 'div > *');
+test_helper($dom, 'div > p');
+test_helper($dom, 'div > p + img');
+test_helper($dom, 'div > p ~ img');
+test_helper($dom, 'body > img');
+test_helper($dom, 'div.bar.baz > p');
+test_helper($dom, 'article[title].bar p');
+
+try {
+    test_helper($dom, 'col.selected||td');
+} catch (ValueError $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+--- Selector: nonsense ---
+--- Selector: p ---
+<p xmlns="http://www.w3.org/1999/xhtml">First p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Second p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+<p xmlns="http://www.w3.org/1999/xhtml" class="bar">Fifth p</p>
+--- Selector: p, img ---
+<p xmlns="http://www.w3.org/1999/xhtml">First p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Second p</p>
+<img xmlns="http://www.w3.org/1999/xhtml" src="1.png" />
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<img xmlns="http://www.w3.org/1999/xhtml" src="2.png" />
+<img xmlns="http://www.w3.org/1999/xhtml" src="3.png" />
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+<p xmlns="http://www.w3.org/1999/xhtml" class="bar">Fifth p</p>
+--- Selector: body p ---
+<p xmlns="http://www.w3.org/1999/xhtml">First p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Second p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+<p xmlns="http://www.w3.org/1999/xhtml" class="bar">Fifth p</p>
+--- Selector: body div p ---
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+--- Selector: div > * ---
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<img xmlns="http://www.w3.org/1999/xhtml" src="2.png" />
+<img xmlns="http://www.w3.org/1999/xhtml" src="3.png" />
+<div xmlns="http://www.w3.org/1999/xhtml" class="foo bar baz">
+                <p>Fourth p</p>
+            </div>
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+--- Selector: div > p ---
+<p xmlns="http://www.w3.org/1999/xhtml">Third p</p>
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+--- Selector: div > p + img ---
+<img xmlns="http://www.w3.org/1999/xhtml" src="2.png" />
+--- Selector: div > p ~ img ---
+<img xmlns="http://www.w3.org/1999/xhtml" src="2.png" />
+<img xmlns="http://www.w3.org/1999/xhtml" src="3.png" />
+--- Selector: body > img ---
+<img xmlns="http://www.w3.org/1999/xhtml" src="1.png" />
+--- Selector: div.bar.baz > p ---
+<p xmlns="http://www.w3.org/1999/xhtml">Fourth p</p>
+--- Selector: article[title].bar p ---
+<p xmlns="http://www.w3.org/1999/xhtml" class="bar">Fifth p</p>
+--- Selector: col.selected||td ---
+Dom\Document::querySelectorAll(): Argument #1 ($selectors) contains an unsupported selector
--- a/ext/dom/tests/modern/css_selectors/entities.phpt
+++ b/ext/dom/tests/modern/css_selectors/entities.phpt
@ -0,0 +1,26 @@
+--TEST--
+CSS Selectors - Handling entities
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = Dom\XMLDocument::createFromString(<<<XML
+<!DOCTYPE root [
+    <!ENTITY ent "box">
+]>
+<root>
+    <input type="check&ent;" checked="" class="a&ent;a" id="a&ent;a" xmlns="http://www.w3.org/1999/xhtml"/>
+</root>
+XML);
+var_dump($dom->querySelector('input:checked')->nodeName);
+var_dump($dom->querySelector('input[type$="ox"]')->nodeName);
+var_dump($dom->querySelector('input.aboxa')->nodeName);
+var_dump($dom->querySelector('input#aboxa')->nodeName);
+
+?>
+--EXPECT--
+string(5) "input"
+string(5) "input"
+string(5) "input"
+string(5) "input"
--- a/ext/dom/tests/modern/css_selectors/id.phpt
+++ b/ext/dom/tests/modern/css_selectors/id.phpt
@ -0,0 +1,35 @@
+--TEST--
+CSS Selectors - ID
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <test id="test1"/>
+    <test/>
+    <test id="test2"/>
+    <test id="test3"/>
+    <test xmlns:x="urn:x" x:id="test4"/>
+</container>
+XML);
+
+test_helper($dom, '#test');
+test_helper($dom, '#test1');
+test_helper($dom, '#test2');
+test_helper($dom, '#test3');
+test_helper($dom, '#test4');
+
+?>
+--EXPECT--
+--- Selector: #test ---
+--- Selector: #test1 ---
+<test id="test1"/>
+--- Selector: #test2 ---
+<test id="test2"/>
+--- Selector: #test3 ---
+<test id="test3"/>
+--- Selector: #test4 ---
--- a/ext/dom/tests/modern/css_selectors/matches_invalid_selector.phpt
+++ b/ext/dom/tests/modern/css_selectors/matches_invalid_selector.phpt
@ -0,0 +1,18 @@
+--TEST--
+Test DOM\Element::matches() method: invalid selector
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = DOM\XMLDocument::createFromString("<root/>");
+
+try {
+  var_dump($dom->documentElement->matches('@invalid'));
+} catch (DOMException $e) {
+  echo $e->getMessage();
+}
+
+?>
+--EXPECT--
+Invalid selector (Selectors. Unexpected token: @invalid)
--- a/ext/dom/tests/modern/css_selectors/namespaces.phpt
+++ b/ext/dom/tests/modern/css_selectors/namespaces.phpt
@ -0,0 +1,54 @@
+--TEST--
+CSS Selectors - Namespaces
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<root>
+    <container align="left"/>
+    <only>
+        <a xmlns="urn:a"/>
+        <a xmlns="urn:a"/>
+        <a xmlns="urn:b"/>
+        <a xmlns=""/>
+        <a/>
+    </only>
+</root>
+XML);
+
+$container = $dom->documentElement->firstElementChild;
+$container->setAttribute("foo:bar", "baz");
+$container->setAttributeNS("urn:a", "a:bar", "baz");
+
+test_helper($dom, 'container[align]');
+test_helper($dom, 'container[foo\\:bar]');
+test_helper($dom, 'container[a\\:bar]');
+test_helper($dom, 'container[bar]');
+
+test_helper($dom, 'a:first-of-type');
+test_helper($dom, 'a:last-of-type');
+
+test_failure($dom, 'container[* | bar]');
+
+?>
+--EXPECT--
+--- Selector: container[align] ---
+<container align="left" foo:bar="baz" xmlns:a="urn:a" a:bar="baz"/>
+--- Selector: container[foo\:bar] ---
+<container align="left" foo:bar="baz" xmlns:a="urn:a" a:bar="baz"/>
+--- Selector: container[a\:bar] ---
+--- Selector: container[bar] ---
+--- Selector: a:first-of-type ---
+<a xmlns="urn:a"/>
+<a xmlns="urn:b"/>
+<a xmlns=""/>
+--- Selector: a:last-of-type ---
+<a xmlns="urn:a"/>
+<a xmlns="urn:b"/>
+<a/>
+--- Selector: container[* | bar] ---
+Code 12 Invalid selector (Selectors. Unexpected token: *)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_blank.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_blank.phpt
@ -0,0 +1,23 @@
+--TEST--
+CSS Selectors - Pseudo classes: blank
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container/>
+XML);
+
+try {
+    test_helper($dom, ':blank');
+} catch (DOMException $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+--- Selector: :blank ---
+:blank selector is not implemented because CSSWG has not yet decided its semantics (https://github.com/w3c/csswg-drafts/issues/1967)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_checked.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_checked.phpt
@ -0,0 +1,27 @@
+--TEST--
+CSS Selectors - Pseudo classes: checked
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <input type="checkbox" checked="checked" />
+    <input type="radio" checked="checked" />
+    <option selected="" />
+    <option xmlns="" selected="" />
+    <input/>
+</html>
+XML);
+
+test_helper($dom, ':checked');
+
+?>
+--EXPECT--
+--- Selector: :checked ---
+<input xmlns="http://www.w3.org/1999/xhtml" type="checkbox" checked="checked" />
+<input xmlns="http://www.w3.org/1999/xhtml" type="radio" checked="checked" />
+<option xmlns="http://www.w3.org/1999/xhtml" selected=""></option>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_current.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_current.phpt
@ -0,0 +1,21 @@
+--TEST--
+CSS Selectors - Pseudo classes: current
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <div/>
+</html>
+XML);
+
+test_helper($dom, ':current(div)');
+
+?>
+--EXPECT--
+--- Selector: :current(div) ---
+<div xmlns="http://www.w3.org/1999/xhtml"></div>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_dir.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_dir.phpt
@ -0,0 +1,27 @@
+--TEST--
+CSS Selectors - Pseudo classes: dir
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container dir="rtl">
+    <p>1</p>
+    <html xmlns="http://www.w3.org/1999/xhtml" dir="ltr">
+        <p>2</p>
+    </html>
+</container>
+XML);
+
+test_failure($dom, ':dir(rtl)', true);
+test_failure($dom, ':dir(ltr)', true);
+
+?>
+--EXPECT--
+--- Selector: :dir(rtl) ---
+Code 12 Invalid selector (Selectors. Not supported: dir)
+--- Selector: :dir(ltr) ---
+Code 12 Invalid selector (Selectors. Not supported: dir)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_disabled_enabled.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_disabled_enabled.phpt
@ -0,0 +1,107 @@
+--TEST--
+CSS Selectors - Pseudo classes: disabled/enabled
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <button/>
+    <button xmlns="" disabled="disabled"/>
+    <button disabled="disabled"/>
+    <input disabled="disabled"/>
+    <select disabled="disabled"/>
+    <textarea disabled="disabled"/>
+    <optgroup disabled="disabled"/>
+
+    <!-- fieldset rules are complicated -->
+    <fieldset disabled="disabled"/>
+    <fieldset disabled="disabled">
+        <fieldset id="1"/>
+    </fieldset>
+    <fieldset disabled="disabled">
+        <!-- foo -->
+        <legend>
+            <div>
+                <fieldset id="2"/>
+            </div>
+        </legend>
+        <div>
+            <fieldset id="3"/>
+        </div>
+    </fieldset>
+</html>
+XML);
+
+test_helper($dom, '*:disabled');
+test_helper($dom, '*:enabled');
+
+?>
+--EXPECT--
+--- Selector: *:disabled ---
+<button xmlns="http://www.w3.org/1999/xhtml" disabled="disabled"></button>
+<input xmlns="http://www.w3.org/1999/xhtml" disabled="disabled" />
+<select xmlns="http://www.w3.org/1999/xhtml" disabled="disabled"></select>
+<textarea xmlns="http://www.w3.org/1999/xhtml" disabled="disabled"></textarea>
+<optgroup xmlns="http://www.w3.org/1999/xhtml" disabled="disabled"></optgroup>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" disabled="disabled"></fieldset>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" disabled="disabled">
+        <fieldset id="1"></fieldset>
+    </fieldset>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" disabled="disabled">
+        <!-- foo -->
+        <legend>
+            <div>
+                <fieldset id="2"></fieldset>
+            </div>
+        </legend>
+        <div>
+            <fieldset id="3"></fieldset>
+        </div>
+    </fieldset>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" id="3"></fieldset>
+--- Selector: *:enabled ---
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <button></button>
+    <button xmlns="" disabled="disabled"/>
+    <button disabled="disabled"></button>
+    <input disabled="disabled" />
+    <select disabled="disabled"></select>
+    <textarea disabled="disabled"></textarea>
+    <optgroup disabled="disabled"></optgroup>
+
+    <!-- fieldset rules are complicated -->
+    <fieldset disabled="disabled"></fieldset>
+    <fieldset disabled="disabled">
+        <fieldset id="1"></fieldset>
+    </fieldset>
+    <fieldset disabled="disabled">
+        <!-- foo -->
+        <legend>
+            <div>
+                <fieldset id="2"></fieldset>
+            </div>
+        </legend>
+        <div>
+            <fieldset id="3"></fieldset>
+        </div>
+    </fieldset>
+</html>
+<button xmlns="http://www.w3.org/1999/xhtml"></button>
+<button xmlns="" disabled="disabled"/>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" id="1"></fieldset>
+<legend xmlns="http://www.w3.org/1999/xhtml">
+            <div>
+                <fieldset id="2"></fieldset>
+            </div>
+        </legend>
+<div xmlns="http://www.w3.org/1999/xhtml">
+                <fieldset id="2"></fieldset>
+            </div>
+<fieldset xmlns="http://www.w3.org/1999/xhtml" id="2"></fieldset>
+<div xmlns="http://www.w3.org/1999/xhtml">
+            <fieldset id="3"></fieldset>
+        </div>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_empty.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_empty.phpt
@ -0,0 +1,38 @@
+--TEST--
+CSS Selectors - Pseudo classes: empty
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <div class="empty">
+        <p>Element with no content:</p>
+        <div></div>
+
+        <p>Element with comment:</p>
+        <div><!-- Simple Comment --></div>
+
+        <p>Element with PI:</p>
+        <div><?foo?></div>
+
+        <p>Element with CDATA:</p>
+        <div><![CDATA[foo]]></div>
+
+        <p>Element with nested empty element:</p>
+        <div><p></p></div>
+    </div>
+</container>
+XML);
+
+test_helper($dom, '.empty > div:empty');
+
+?>
+--EXPECT--
+--- Selector: .empty > div:empty ---
+<div/>
+<div><!-- Simple Comment --></div>
+<div><?foo ?></div>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_first_last_child.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_first_last_child.phpt
@ -0,0 +1,29 @@
+--TEST--
+CSS Selectors - Pseudo classes: first/last child
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <?foo?>
+    <!--bar-->
+    <first />
+    &amp;
+    <last/>
+    <![CDATA[skip me]]>
+</container>
+XML);
+
+test_helper($dom, 'container > *:first-child');
+test_helper($dom, 'container > *:last-child');
+
+?>
+--EXPECT--
+--- Selector: container > *:first-child ---
+<first/>
+--- Selector: container > *:last-child ---
+<last/>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_has.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_has.phpt
@ -0,0 +1,33 @@
+--TEST--
+CSS Selectors - Pseudo classes: has
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <div>
+        <p class="foo"/>
+    </div>
+    <div>
+        <p/>
+    </div>
+</container>
+XML);
+
+test_helper($dom, 'div:has(p.foo)');
+test_helper($dom, 'div:has(:not(p.foo))');
+
+?>
+--EXPECT--
+--- Selector: div:has(p.foo) ---
+<div>
+        <p class="foo"/>
+    </div>
+--- Selector: div:has(:not(p.foo)) ---
+<div>
+        <p/>
+    </div>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_is_where.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_is_where.phpt
@ -0,0 +1,34 @@
+--TEST--
+CSS Selectors - Pseudo classes: is/where
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <article>
+        <p>1</p>
+    </article>
+    <main>
+        <p>2</p>
+    </main>
+    <div>
+        <p>3</p>
+    </div>
+</container>
+XML);
+
+test_helper($dom, ':is(article, main) p');
+test_helper($dom, ':where(article, main) p');
+
+?>
+--EXPECT--
+--- Selector: :is(article, main) p ---
+<p>1</p>
+<p>2</p>
+--- Selector: :where(article, main) p ---
+<p>1</p>
+<p>2</p>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_lang.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_lang.phpt
@ -0,0 +1,27 @@
+--TEST--
+CSS Selectors - Pseudo classes: lang
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container lang="en">
+    <p>1</p>
+    <html xmlns="http://www.w3.org/1999/xhtml" lang="nl">
+        <p>2</p>
+    </html>
+</container>
+XML);
+
+test_failure($dom, ':lang(en)', true);
+test_failure($dom, ':lang(nl)', true);
+
+?>
+--EXPECT--
+--- Selector: :lang(en) ---
+Code 12 Invalid selector (Selectors. Not supported: lang)
+--- Selector: :lang(nl) ---
+Code 12 Invalid selector (Selectors. Not supported: lang)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_links.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_links.phpt
@ -0,0 +1,31 @@
+--TEST--
+CSS Selectors - Pseudo classes: links
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <a href="http://example.com">Link</a>
+    <a xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</a>
+    <area xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</area>
+</container>
+XML);
+
+test_helper($dom, ':any-link');
+test_helper($dom, ':link');
+test_helper($dom, 'a:not(:any-link)');
+
+?>
+--EXPECT--
+--- Selector: :any-link ---
+<a xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</a>
+<area xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</area>
+--- Selector: :link ---
+<a xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</a>
+<area xmlns="http://www.w3.org/1999/xhtml" href="http://example.com">Link</area>
+--- Selector: a:not(:any-link) ---
+<a href="http://example.com">Link</a>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_no_op.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_no_op.phpt
@ -0,0 +1,83 @@
+--TEST--
+CSS Selectors - Pseudo classes: no-ops
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <div/>
+    <a href="#foo"/>
+</html>
+XML);
+
+// These will always fail or return an empty list because they are display-specific or require user interaction
+test_failure($dom, ':default');
+test_failure($dom, ':focus');
+test_failure($dom, ':focus-visible');
+test_failure($dom, ':focus-within');
+test_failure($dom, ':fullscreen');
+test_failure($dom, ':hover');
+test_failure($dom, ':in-range');
+test_failure($dom, ':indeterminate');
+test_failure($dom, ':invalid');
+test_failure($dom, ':out-of-range');
+test_failure($dom, ':past');
+test_failure($dom, ':future');
+test_failure($dom, ':scope');
+test_failure($dom, ':target');
+test_failure($dom, ':target-within');
+test_failure($dom, ':user-invalid');
+test_failure($dom, ':valid');
+test_failure($dom, ':visited');
+test_failure($dom, ':warning');
+test_failure($dom, ':local-link');
+test_failure($dom, ':active');
+
+?>
+--EXPECT--
+--- Selector: :default ---
+Code 12 Invalid selector (Selectors. Not supported: default)
+--- Selector: :focus ---
+int(0)
+--- Selector: :focus-visible ---
+Code 12 Invalid selector (Selectors. Not supported: focus-visible)
+--- Selector: :focus-within ---
+Code 12 Invalid selector (Selectors. Not supported: focus-within)
+--- Selector: :fullscreen ---
+Code 12 Invalid selector (Selectors. Not supported: fullscreen)
+--- Selector: :hover ---
+int(0)
+--- Selector: :in-range ---
+Code 12 Invalid selector (Selectors. Not supported: in-range)
+--- Selector: :indeterminate ---
+Code 12 Invalid selector (Selectors. Not supported: indeterminate)
+--- Selector: :invalid ---
+Code 12 Invalid selector (Selectors. Not supported: invalid)
+--- Selector: :out-of-range ---
+Code 12 Invalid selector (Selectors. Not supported: out-of-range)
+--- Selector: :past ---
+Code 12 Invalid selector (Selectors. Not supported: past)
+--- Selector: :future ---
+Code 12 Invalid selector (Selectors. Not supported: future)
+--- Selector: :scope ---
+Code 12 Invalid selector (Selectors. Not supported: scope)
+--- Selector: :target ---
+Code 12 Invalid selector (Selectors. Not supported: target)
+--- Selector: :target-within ---
+Code 12 Invalid selector (Selectors. Not supported: target-within)
+--- Selector: :user-invalid ---
+Code 12 Invalid selector (Selectors. Not supported: user-invalid)
+--- Selector: :valid ---
+Code 12 Invalid selector (Selectors. Not supported: valid)
+--- Selector: :visited ---
+Code 12 Invalid selector (Selectors. Not supported: visited)
+--- Selector: :warning ---
+Code 12 Invalid selector (Selectors. Not supported: warning)
+--- Selector: :local-link ---
+Code 12 Invalid selector (Selectors. Not supported: local-link)
+--- Selector: :active ---
+int(0)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_child.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_child.phpt
@ -0,0 +1,56 @@
+--TEST--
+CSS Selectors - Pseudo classes: nth-child
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <h2>1</h2>
+    <h2>2</h2>
+    <h2>3</h2>
+    <h2>4</h2>
+    <h2>5</h2>
+</container>
+XML);
+
+test_helper($dom, 'h2:nth-of-type(n+2):nth-last-of-type(n+2)');
+test_helper($dom, 'h2:not(:first-of-type):not(:last-of-type)'); // Equivalent to the above
+test_helper($dom, 'h2:nth-child(2)');
+test_helper($dom, 'h2:nth-last-child(2)');
+test_helper($dom, 'h2:nth-child(2n + 1)');
+test_helper($dom, 'h2:nth-last-child(2n + 1)');
+test_helper($dom, 'h2:nth-child(3n - 2)');
+test_helper($dom, 'h2:nth-last-child(3n - 2)');
+
+?>
+--EXPECT--
+--- Selector: h2:nth-of-type(n+2):nth-last-of-type(n+2) ---
+<h2>2</h2>
+<h2>3</h2>
+<h2>4</h2>
+--- Selector: h2:not(:first-of-type):not(:last-of-type) ---
+<h2>2</h2>
+<h2>3</h2>
+<h2>4</h2>
+--- Selector: h2:nth-child(2) ---
+<h2>2</h2>
+--- Selector: h2:nth-last-child(2) ---
+<h2>4</h2>
+--- Selector: h2:nth-child(2n + 1) ---
+<h2>1</h2>
+<h2>3</h2>
+<h2>5</h2>
+--- Selector: h2:nth-last-child(2n + 1) ---
+<h2>1</h2>
+<h2>3</h2>
+<h2>5</h2>
+--- Selector: h2:nth-child(3n - 2) ---
+<h2>1</h2>
+<h2>4</h2>
+--- Selector: h2:nth-last-child(3n - 2) ---
+<h2>2</h2>
+<h2>5</h2>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_child_of.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_child_of.phpt
@ -0,0 +1,56 @@
+--TEST--
+CSS Selectors - Pseudo classes: nth-child of
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <h2 class="hi">1</h2>
+    <h2>2</h2>
+    <h2 class="hi">3</h2>
+    <h2 class="hi">4</h2>
+    <h2>5</h2>
+    <h2 class="hi">6</h2>
+</container>
+XML);
+
+test_helper($dom, 'h2:nth-child(even of .hi)');
+test_helper($dom, 'h2.hi:nth-child(even)');
+test_helper($dom, 'h2:nth-child(odd of .hi)');
+test_helper($dom, 'h2.hi:nth-child(odd)');
+
+test_helper($dom, 'h2:nth-last-child(even of .hi)');
+test_helper($dom, 'h2.hi:nth-last-child(even)');
+test_helper($dom, 'h2:nth-last-child(odd of .hi)');
+test_helper($dom, 'h2.hi:nth-last-child(odd)');
+
+?>
+--EXPECT--
+--- Selector: h2:nth-child(even of .hi) ---
+<h2 class="hi">3</h2>
+<h2 class="hi">6</h2>
+--- Selector: h2.hi:nth-child(even) ---
+<h2 class="hi">4</h2>
+<h2 class="hi">6</h2>
+--- Selector: h2:nth-child(odd of .hi) ---
+<h2 class="hi">1</h2>
+<h2 class="hi">4</h2>
+--- Selector: h2.hi:nth-child(odd) ---
+<h2 class="hi">1</h2>
+<h2 class="hi">3</h2>
+--- Selector: h2:nth-last-child(even of .hi) ---
+<h2 class="hi">1</h2>
+<h2 class="hi">4</h2>
+--- Selector: h2.hi:nth-last-child(even) ---
+<h2 class="hi">1</h2>
+<h2 class="hi">3</h2>
+--- Selector: h2:nth-last-child(odd of .hi) ---
+<h2 class="hi">3</h2>
+<h2 class="hi">6</h2>
+--- Selector: h2.hi:nth-last-child(odd) ---
+<h2 class="hi">4</h2>
+<h2 class="hi">6</h2>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_col.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_nth_col.phpt
@ -0,0 +1,36 @@
+--TEST--
+CSS Selectors - Pseudo classes: nth-(last-)col
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\HTMLDocument::createFromString(<<<HTML
+<!DOCTYPE html>
+<html>
+    <body>
+        <table>
+            <tr>
+                <th>Col 1</th>
+                <th>Col 2</th>
+            </tr>
+            <tr>
+                <td>1</td>
+                <td>2</td>
+            </tr>
+        </table>
+    </body>
+</html>
+HTML);
+
+test_failure($dom, ':nth-col(1)', true);
+test_failure($dom, ':nth-last-col(1)', true);
+
+?>
+--EXPECT--
+--- Selector: :nth-col(1) ---
+Code 12 Invalid selector (Selectors. Not supported: nth-col)
+--- Selector: :nth-last-col(1) ---
+Code 12 Invalid selector (Selectors. Not supported: nth-last-col)
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_only_child.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_only_child.phpt
@ -0,0 +1,29 @@
+--TEST--
+CSS Selectors - Pseudo classes: only-child
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <div class="only-child1">
+        <p>Lonely</p>
+    </div>
+    <div class="only-child2">
+        <p>With 2</p>
+        <p>With 2</p>
+    </div>
+</container>
+XML);
+
+test_helper($dom, '.only-child1 p:only-child');
+test_helper($dom, '.only-child2 p:only-child');
+
+?>
+--EXPECT--
+--- Selector: .only-child1 p:only-child ---
+<p>Lonely</p>
+--- Selector: .only-child2 p:only-child ---
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_only_of_type.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_only_of_type.phpt
@ -0,0 +1,36 @@
+--TEST--
+CSS Selectors - Pseudo classes: only-of-type
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <div class="only-of-type1">
+        <p>Alone</p>
+    </div>
+    <div class="only-of-type2">
+        <p>With 2</p>
+        <p>With 2</p>
+    </div>
+    <div class="only-of-type3">
+        <p>With 2</p>
+        <div/>
+        <p>With 2</p>
+    </div>
+</container>
+XML);
+
+test_helper($dom, '.only-of-type1 p:only-of-type');
+test_helper($dom, '.only-of-type2 p:only-of-type');
+test_helper($dom, '.only-of-type3 p:only-of-type');
+
+?>
+--EXPECT--
+--- Selector: .only-of-type1 p:only-of-type ---
+<p>Alone</p>
+--- Selector: .only-of-type2 p:only-of-type ---
+--- Selector: .only-of-type3 p:only-of-type ---
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_optional_required.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_optional_required.phpt
@ -0,0 +1,35 @@
+--TEST--
+CSS Selectors - Pseudo classes: optional/required
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <input type="checkbox" required="required" />
+    <select required="required" />
+    <textarea required="" />
+    <input type="checkbox" />
+    <select />
+    <textarea />
+    <input xmlns=""/>
+    <input xmlns="" required="" />
+</html>
+XML);
+
+test_helper($dom, ':required');
+test_helper($dom, ':optional');
+
+?>
+--EXPECT--
+--- Selector: :required ---
+<input xmlns="http://www.w3.org/1999/xhtml" type="checkbox" required="required" />
+<select xmlns="http://www.w3.org/1999/xhtml" required="required"></select>
+<textarea xmlns="http://www.w3.org/1999/xhtml" required=""></textarea>
+--- Selector: :optional ---
+<input xmlns="http://www.w3.org/1999/xhtml" type="checkbox" />
+<select xmlns="http://www.w3.org/1999/xhtml"></select>
+<textarea xmlns="http://www.w3.org/1999/xhtml"></textarea>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_placeholder_shown.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_placeholder_shown.phpt
@ -0,0 +1,27 @@
+--TEST--
+CSS Selectors - Pseudo classes: placeholder-shown
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <input type="text" placeholder="" />
+    <textarea placeholder="" />
+    <input xmlns="" type="text" placeholder="" />
+    <textarea xmlns="" placeholder="" />
+    <input type="text" />
+    <textarea />
+</html>
+XML);
+
+test_helper($dom, ':placeholder-shown');
+
+?>
+--EXPECT--
+--- Selector: :placeholder-shown ---
+<input xmlns="http://www.w3.org/1999/xhtml" type="text" placeholder="" />
+<textarea xmlns="http://www.w3.org/1999/xhtml" placeholder=""></textarea>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_read_write_read_only.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_read_write_read_only.phpt
@ -0,0 +1,53 @@
+--TEST--
+CSS Selectors - Pseudo classes: read-write/read-only
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <input type="text" readonly="" />
+    <textarea readonly="" />
+    <input type="text" disabled="" />
+    <textarea disabled="" />
+    <input type="text" xmlns="" />
+    <textarea xmlns="" />
+    <input type="text" />
+    <textarea />
+    <p contenteditable="" />
+    <p contenteditable="false" />
+</html>
+XML);
+
+test_helper($dom, ':read-write');
+test_helper($dom, ':read-only');
+
+?>
+--EXPECT--
+--- Selector: :read-write ---
+<input xmlns="http://www.w3.org/1999/xhtml" type="text" />
+<textarea xmlns="http://www.w3.org/1999/xhtml"></textarea>
+<p xmlns="http://www.w3.org/1999/xhtml" contenteditable=""></p>
+--- Selector: :read-only ---
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <input type="text" readonly="" />
+    <textarea readonly=""></textarea>
+    <input type="text" disabled="" />
+    <textarea disabled=""></textarea>
+    <input xmlns="" type="text"/>
+    <textarea xmlns=""/>
+    <input type="text" />
+    <textarea></textarea>
+    <p contenteditable=""></p>
+    <p contenteditable="false"></p>
+</html>
+<input xmlns="http://www.w3.org/1999/xhtml" type="text" readonly="" />
+<textarea xmlns="http://www.w3.org/1999/xhtml" readonly=""></textarea>
+<input xmlns="http://www.w3.org/1999/xhtml" type="text" disabled="" />
+<textarea xmlns="http://www.w3.org/1999/xhtml" disabled=""></textarea>
+<input xmlns="" type="text"/>
+<textarea xmlns=""/>
+<p xmlns="http://www.w3.org/1999/xhtml" contenteditable="false"></p>
--- a/ext/dom/tests/modern/css_selectors/pseudo_classes_root.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_classes_root.phpt
@ -0,0 +1,29 @@
+--TEST--
+CSS Selectors - Pseudo classes: root
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container/>
+XML);
+
+test_helper($dom, ':root', true);
+$fragment = $dom->createDocumentFragment();
+$fragment->appendXML('<div><p></p></div>');
+test_helper($fragment, ':root', true);
+test_helper($dom->createElement("foo"), ':root', true);
+
+test_helper($dom->createElement("not-a-root"), ":root", true);
+
+?>
+--EXPECT--
+--- Selector: :root ---
+container
+--- Selector: :root ---
+div
+--- Selector: :root ---
+--- Selector: :root ---
--- a/ext/dom/tests/modern/css_selectors/pseudo_elements.phpt
+++ b/ext/dom/tests/modern/css_selectors/pseudo_elements.phpt
@ -0,0 +1,55 @@
+--TEST--
+CSS Selectors - Pseudo elements
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+$dom = DOM\XMLDocument::createFromString(<<<XML
+<container>
+    <a/>
+</container>
+XML);
+
+// Pseudo-elements can't work in a static DOM
+test_failure($dom, 'a::after');
+test_failure($dom, 'a::before');
+test_failure($dom, 'a::backdrop');
+test_failure($dom, 'a::first-letter');
+test_failure($dom, 'a::first-line');
+test_failure($dom, 'a::grammar-error');
+test_failure($dom, 'a::inactive-selection');
+test_failure($dom, 'a::marker');
+test_failure($dom, 'a::placeholder');
+test_failure($dom, 'a::selection');
+test_failure($dom, 'a::spelling-error');
+test_failure($dom, 'a::target-text');
+
+?>
+--EXPECT--
+--- Selector: a::after ---
+Code 12 Invalid selector (Selectors. Not supported: after)
+--- Selector: a::before ---
+Code 12 Invalid selector (Selectors. Not supported: before)
+--- Selector: a::backdrop ---
+Code 12 Invalid selector (Selectors. Not supported: backdrop)
+--- Selector: a::first-letter ---
+Code 12 Invalid selector (Selectors. Not supported: first-letter)
+--- Selector: a::first-line ---
+Code 12 Invalid selector (Selectors. Not supported: first-line)
+--- Selector: a::grammar-error ---
+Code 12 Invalid selector (Selectors. Not supported: grammar-error)
+--- Selector: a::inactive-selection ---
+Code 12 Invalid selector (Selectors. Not supported: inactive-selection)
+--- Selector: a::marker ---
+Code 12 Invalid selector (Selectors. Not supported: marker)
+--- Selector: a::placeholder ---
+Code 12 Invalid selector (Selectors. Not supported: placeholder)
+--- Selector: a::selection ---
+Code 12 Invalid selector (Selectors. Not supported: selection)
+--- Selector: a::spelling-error ---
+Code 12 Invalid selector (Selectors. Not supported: spelling-error)
+--- Selector: a::target-text ---
+Code 12 Invalid selector (Selectors. Not supported: target-text)
--- a/ext/dom/tests/modern/css_selectors/quirks_mode.phpt
+++ b/ext/dom/tests/modern/css_selectors/quirks_mode.phpt
@ -0,0 +1,68 @@
+--TEST--
+CSS Selectors - Quirks mode test
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+require __DIR__ . '/test_utils.inc';
+
+echo "\n=== Document in quirks mode ===\n\n";
+
+$dom = DOM\HTMLDocument::createFromString(<<<HTML
+<html>
+    <div class="HElLoWorLD"/>
+    <div id="hI"/>
+</html>
+HTML, LIBXML_NOERROR);
+
+test_helper($dom, 'div.helloworld');
+test_helper($dom, 'div.HElLoWorLD');
+test_helper($dom, '#hi');
+test_helper($dom, '#hI');
+
+echo "\n=== Document not in quirks mode ===\n\n";
+
+$dom = DOM\HTMLDocument::createFromString(<<<HTML
+<!DOCTYPE html>
+<html>
+    <div class="HElLoWorLD"/>
+    <div id="hI"/>
+</html>
+HTML, LIBXML_NOERROR);
+
+test_helper($dom, 'div.helloworld');
+test_helper($dom, 'div.HElLoWorLD');
+test_helper($dom, '#hi');
+test_helper($dom, '#hI');
+
+?>
+--EXPECT--
+=== Document in quirks mode ===
+
+--- Selector: div.helloworld ---
+<div xmlns="http://www.w3.org/1999/xhtml" class="HElLoWorLD">
+    <div id="hI">
+</div></div>
+--- Selector: div.HElLoWorLD ---
+<div xmlns="http://www.w3.org/1999/xhtml" class="HElLoWorLD">
+    <div id="hI">
+</div></div>
+--- Selector: #hi ---
+<div xmlns="http://www.w3.org/1999/xhtml" id="hI">
+</div>
+--- Selector: #hI ---
+<div xmlns="http://www.w3.org/1999/xhtml" id="hI">
+</div>
+
+=== Document not in quirks mode ===
+
+--- Selector: div.helloworld ---
+--- Selector: div.HElLoWorLD ---
+<div xmlns="http://www.w3.org/1999/xhtml" class="HElLoWorLD">
+    <div id="hI">
+</div></div>
+--- Selector: #hi ---
+--- Selector: #hI ---
+<div xmlns="http://www.w3.org/1999/xhtml" id="hI">
+</div>
--- a/ext/dom/tests/modern/css_selectors/test_utils.inc
+++ b/ext/dom/tests/modern/css_selectors/test_utils.inc
@ -0,0 +1,46 @@
+<?php
+
+function test_helper(DOM\ParentNode $dom, string $selector, bool $only_name = false)
+{
+    echo "--- Selector: $selector ---\n";
+
+    $all = $dom->querySelectorAll($selector);
+    $single = $dom->querySelector($selector);
+
+    if ((count($all) === 0 && $single !== null) || ($all[0] !== $single)) {
+        throw new Exception('Mismatch in querySelector and querySelectorAll');
+    }
+
+    $list = [];
+    foreach ($all as $node) {
+        $list[] = $node;
+
+        if ($only_name) {
+            echo $node->nodeName, "\n";
+            continue;
+        }
+
+        echo $dom->saveXML($node), "\n";
+    }
+
+    // If the element is in the list, then it must match, otherwise it must not
+    // This loops over all the elements in the document and checks them
+    foreach ($dom->querySelectorAll('*') as $node) {
+        if (in_array($node, $list, true) !== $node->matches($selector)) {
+            var_dump($node, $selector, in_array($node, $list, true), $node->matches($selector));
+            echo $dom->saveXML($node), "\n";
+            throw new Exception('Bug in Element::matches()');
+        }
+    }
+}
+
+function test_failure(DOM\ParentNode $dom, string $selector)
+{
+    echo "--- Selector: $selector ---\n";
+
+    try {
+        var_dump(count($dom->querySelectorAll($selector)));
+    } catch (DOMException $e) {
+        echo "Code ", $e->getCode(), " ", $e->getMessage(), "\n";
+    }
+}
--- a/ext/libxml/libxml.c
+++ b/ext/libxml/libxml.c
@ -1350,6 +1350,7 @@ PHP_LIBXML_API int php_libxml_increment_doc_ref(php_libxml_node_object *object,
 		object->document->private_data = NULL;
 		object->document->class_type = PHP_LIBXML_CLASS_UNSET;
 		object->document->handlers = &php_libxml_default_document_handlers;
+		object->document->quirks_mode = false;
 	}

 	return ret_refcount;
--- a/ext/libxml/php_libxml.h
+++ b/ext/libxml/php_libxml.h
@ -102,7 +102,8 @@ typedef struct _php_libxml_ref_obj {
 	php_libxml_private_data_header *private_data;
 	const php_libxml_document_handlers *handlers;
 	int refcount;
-	php_libxml_class_type class_type;
+	php_libxml_class_type class_type : 8;
+	bool quirks_mode;
 } php_libxml_ref_obj;

 typedef struct _php_libxml_node_ptr {