Markdown: Remove loose-item plugin (#14372)

src/language-markdown/clean.js

@@ -25,7 +25,6 @@ function clean(ast, newObj, parent) {
 
   if (ast.type === "list" || ast.type === "listItem") {
     delete newObj.spread;
-    delete newObj.loose;
   }
 
   // texts can be splitted or merged

src/language-markdown/parser-markdown.js

@@ -9,7 +9,6 @@ import htmlToJsx from "./unified-plugins/html-to-jsx.js";
 import frontMatter from "./unified-plugins/front-matter.js";
 import liquid from "./unified-plugins/liquid.js";
 import wikiLink from "./unified-plugins/wiki-link.js";
-import looseItems from "./unified-plugins/loose-items.js";
 
 /**
  * based on [MDAST](https://github.com/syntax-tree/mdast) with following modifications:
@@ -38,8 +37,7 @@ function createParse({ isMDX }) {
       .use(isMDX ? esSyntax : identity)
       .use(liquid)
       .use(isMDX ? htmlToJsx : identity)
-      .use(wikiLink)
-      .use(looseItems);
+      .use(wikiLink);
     return processor.run(processor.parse(text));
   };
 }

src/language-markdown/printer-markdown.js

@@ -651,7 +651,7 @@ function printChildren(path, options, print, events = {}) {
         parts.push(hardline);
 
         if (
-          shouldPrePrintDoubleHardline(path) ||
+          shouldPrePrintDoubleHardline(path, options) ||
           shouldPrePrintTripleHardline(path)
         ) {
           parts.push(hardline);
@@ -720,37 +720,44 @@ function shouldPrePrintHardline({ node, parent }) {
   return !isInlineNode && !isInlineHTML;
 }
 
-function shouldPrePrintDoubleHardline({ node, previous, parent }) {
+function isLooseListItem(node, options) {
+  return (
+    node.type === "listItem" &&
+    (node.spread ||
+      // Check if `listItem` ends with `\n`
+      // since it can't be empty, so we only need check the last character
+      options.originalText.charAt(node.position.end.offset - 1) === "\n")
+  );
+}
+
+function shouldPrePrintDoubleHardline({ node, previous, parent }, options) {
+  const isPrevNodeLooseListItem = isLooseListItem(previous, options);
+
+  if (isPrevNodeLooseListItem) {
+    return true;
+  }
+
   const isSequence = previous.type === node.type;
   const isSiblingNode = isSequence && SIBLING_NODE_TYPES.has(node.type);
-
-  const isInTightListItem = parent.type === "listItem" && !parent.loose;
-
-  const isPrevNodeLooseListItem =
-    previous.type === "listItem" && previous.loose;
-
+  const isInTightListItem =
+    parent.type === "listItem" && !isLooseListItem(parent, options);
   const isPrevNodePrettierIgnore = isPrettierIgnore(previous) === "next";
-
   const isBlockHtmlWithoutBlankLineBetweenPrevHtml =
     node.type === "html" &&
     previous.type === "html" &&
     previous.position.end.line + 1 === node.position.start.line;
-
   const isHtmlDirectAfterListItem =
     node.type === "html" &&
     parent.type === "listItem" &&
     previous.type === "paragraph" &&
     previous.position.end.line + 1 === node.position.start.line;
 
-  return (
-    isPrevNodeLooseListItem ||
-    !(
-      isSiblingNode ||
-      isInTightListItem ||
-      isPrevNodePrettierIgnore ||
-      isBlockHtmlWithoutBlankLineBetweenPrevHtml ||
-      isHtmlDirectAfterListItem
-    )
+  return !(
+    isSiblingNode ||
+    isInTightListItem ||
+    isPrevNodePrettierIgnore ||
+    isBlockHtmlWithoutBlankLineBetweenPrevHtml ||
+    isHtmlDirectAfterListItem
   );
 }
 

src/language-markdown/unified-plugins/loose-items.js

@@ -1,33 +0,0 @@
-function looseItems() {
-  const proto = this.Parser.prototype;
-  const originalList = proto.blockTokenizers.list;
-
-  function fixListNodes(value, node, parent) {
-    if (node.type === "listItem") {
-      node.loose = node.spread || value.endsWith("\n");
-      if (node.loose) {
-        parent.loose = true;
-      }
-    }
-    return node;
-  }
-
-  proto.blockTokenizers.list = function list(realEat, value, silent) {
-    function eat(subvalue) {
-      const realAdd = realEat(subvalue);
-
-      function add(node, parent) {
-        return realAdd(fixListNodes(subvalue, node, parent), parent);
-      }
-      add.reset = function (node, parent) {
-        return realAdd.reset(fixListNodes(subvalue, node, parent), parent);
-      };
-
-      return add;
-    }
-    eat.now = realEat.now;
-    return originalList.call(this, eat, value, silent);
-  };
-}
-
-export default looseItems;