From c9ecc384c72e1f1bea1fef461d1d16b2d1f206f8 Mon Sep 17 00:00:00 2001
From: Bogdan Chadkin <trysound@yandex.ru>
Date: Mon, 23 Aug 2021 19:24:04 +0300
Subject: [PATCH] Add descendants test and universal selector support

---
 lib/xast.js      | 26 +++++++++++++-------------
 lib/xast.test.js | 23 +++++++++++++++++++++++
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/lib/xast.js b/lib/xast.js
index 8b6f3edd..adf09894 100644
--- a/lib/xast.js
+++ b/lib/xast.js
@@ -30,7 +30,7 @@ const trimQuotes = (string) => {
  */
 const elementMatches = (csstreeNode, xastElement) => {
   if (csstreeNode.type === 'TypeSelector') {
-    return csstreeNode.name === xastElement.name;
+    return csstreeNode.name === '*' || csstreeNode.name === xastElement.name;
   }
   if (csstreeNode.type === 'IdSelector') {
     return csstreeNode.name === xastElement.attributes.id;
@@ -90,7 +90,7 @@ const elementMatches = (csstreeNode, xastElement) => {
 /**
  * @type {(
  *   startNode: XastParent,
- *   descendants: Array<XastElement>,
+ *   descendants: Set<XastElement>,
  *   parents: WeakMap<XastElement, XastParent>
  * ) => void}
  */
@@ -98,7 +98,7 @@ const collectDescendantElements = (startNode, descendants, parents) => {
   for (const childNode of startNode.children) {
     if (childNode.type === 'element') {
       parents.set(childNode, startNode);
-      descendants.push(childNode);
+      descendants.add(childNode);
       collectDescendantElements(childNode, descendants, parents);
     }
   }
@@ -107,7 +107,7 @@ const collectDescendantElements = (startNode, descendants, parents) => {
 /**
  * @type {(
  *   startNodes: Array<XastElement>,
- *   children: Array<XastElement>,
+ *   children: Set<XastElement>,
  *   parents: WeakMap<XastElement, XastParent>
  * ) => void}
  */
@@ -116,7 +116,7 @@ const collectChildrenElements = (startNodes, children, parents) => {
     for (const child of startNode.children) {
       if (child.type === 'element') {
         parents.set(child, startNode);
-        children.push(child);
+        children.add(child);
       }
     }
   }
@@ -125,7 +125,7 @@ const collectChildrenElements = (startNodes, children, parents) => {
 /**
  * @type {(
  *   startNodes: Array<XastElement>,
- *   siblings: Array<XastElement>,
+ *   siblings: Set<XastElement>,
  *   parents: WeakMap<XastElement, XastParent>
  * ) => void}
  */
@@ -139,7 +139,7 @@ const collectAdjacentSiblings = (startNodes, siblings, parents) => {
       for (const adjacentSibling of adjacentSiblings) {
         if (adjacentSibling.type === 'element') {
           parents.set(adjacentSibling, parentNode);
-          siblings.push(adjacentSibling);
+          siblings.add(adjacentSibling);
         }
       }
     }
@@ -149,7 +149,7 @@ const collectAdjacentSiblings = (startNodes, siblings, parents) => {
 /**
  * @type {(
  *   startNodes: Array<XastElement>,
- *   siblings: Array<XastElement>,
+ *   siblings: Set<XastElement>,
  *   parents: WeakMap<XastElement, XastParent>
  * ) => void}
  */
@@ -163,7 +163,7 @@ const collectGeneralSiblings = (startNodes, siblings, parents) => {
       for (const generalSibling of generalSiblings) {
         if (generalSibling.type === 'element') {
           parents.set(generalSibling, parentNode);
-          siblings.push(generalSibling);
+          siblings.add(generalSibling);
         }
       }
     }
@@ -175,9 +175,9 @@ const collectGeneralSiblings = (startNodes, siblings, parents) => {
  */
 const combination = (csstreeNodes, xastNode) => {
   /**
-   * @type {Array<XastElement>}
+   * @type {Set<XastElement>}
    */
-  let candidateNodes = [];
+  let candidateNodes = new Set();
   /**
    * @type {WeakMap<XastElement, XastParent>}
    */
@@ -189,12 +189,12 @@ const combination = (csstreeNodes, xastNode) => {
   let lastMatchedNodes = [];
   for (const csstreeChild of csstreeNodes) {
     if (csstreeChild.type === 'WhiteSpace') {
+      candidateNodes = new Set();
       for (const node of lastMatchedNodes) {
-        candidateNodes = [];
         collectDescendantElements(node, candidateNodes, candidateParents);
       }
     } else if (csstreeChild.type === 'Combinator') {
-      candidateNodes = [];
+      candidateNodes = new Set();
       if (csstreeChild.name === '>') {
         collectChildrenElements(
           lastMatchedNodes,
diff --git a/lib/xast.test.js b/lib/xast.test.js
index 89be9b8a..62d8b669 100644
--- a/lib/xast.test.js
+++ b/lib/xast.test.js
@@ -74,6 +74,15 @@ test('visit skips entering children if node is detached', () => {
   expect(entered).toEqual(['g', 'ellipse']);
 });
 
+test('select by universal selector', () => {
+  const ast = root([x('g', null, [x('rect'), x('circle')])]);
+  expect(selectAll('*', ast)).toEqual([
+    x('g', null, [x('rect'), x('circle')]),
+    x('rect'),
+    x('circle'),
+  ]);
+});
+
 test('select elements by tag', () => {
   const ast = root([x('g', null, [x('rect')]), x('rect')]);
   expect(selectAll('rect', ast)).toEqual([x('rect'), x('rect')]);
@@ -172,6 +181,20 @@ test('select sibling and child elements', () => {
   ]);
 });
 
+test('select descendants elements', () => {
+  const ast = root([
+    x('g', null, [
+      x('rect', { class: 'inside-g' }),
+      x('g', null, [x('rect', { class: 'inside-deeper-g' })]),
+    ]),
+    x('rect', { class: 'inside-root' }),
+  ]);
+  expect(selectAll('g rect', ast)).toEqual([
+    x('rect', { class: 'inside-g' }),
+    x('rect', { class: 'inside-deeper-g' }),
+  ]);
+});
+
 test('select sibling and child elements', () => {
   const ast = root([
     x('g', null, [