Refactor yaml print (#13632)

src/common/ast-path.js

@@ -57,6 +57,10 @@ class AstPath {
     return this.stack.length === 1;
   }
 
+  get root() {
+    return this.stack[0];
+  }
+
   // The name of the current property is always the penultimate element of
   // this.stack, and always a string/number/symbol.
   getName() {

src/language-yaml/print/flow-mapping-sequence.js

@@ -42,24 +42,21 @@ function printFlowMapping(path, print, options) {
 }
 
 function printChildren(path, print, options) {
-  const { node } = path;
-  const parts = path.map(
-    (childPath, index) => [
+  return path.map(
+    ({ isLast, node, next }) => [
       print(),
-      index === node.children.length - 1
+      isLast
         ? ""
         : [
             ",",
             line,
-            node.children[index].position.start.line !==
-            node.children[index + 1].position.start.line
-              ? printNextEmptyLine(childPath, options.originalText)
+            node.position.start.line !== next.position.start.line
+              ? printNextEmptyLine(path, options.originalText)
               : "",
           ],
     ],
     "children"
   );
-  return parts;
 }
 
 export {

src/language-yaml/print/mapping-item.js

@@ -5,7 +5,6 @@ import {
   group,
   hardline,
   ifBreak,
-  join,
   line,
 } from "../../document/builders.js";
 import {
@@ -19,7 +18,8 @@ import {
 } from "../utils.js";
 import { alignWithSpaces } from "./misc.js";
 
-function printMappingItem(node, parentNode, path, print, options) {
+function printMappingItem(path, print, options) {
+  const { node, parent } = path;
   const { key, value } = node;
 
   const isEmptyMappingKey = isEmptyNode(key);
@@ -33,7 +33,7 @@ function printMappingItem(node, parentNode, path, print, options) {
   const spaceBeforeColon = needsSpaceInFrontOfMappingValue(node) ? " " : "";
 
   if (isEmptyMappingValue) {
-    if (node.type === "flowMappingItem" && parentNode.type === "flowMapping") {
+    if (node.type === "flowMappingItem" && parent.type === "flowMapping") {
       return printedKey;
     }
 
@@ -41,7 +41,7 @@ function printMappingItem(node, parentNode, path, print, options) {
       node.type === "mappingItem" &&
       isAbsolutelyPrintedAsSingleLineNode(key.content, options) &&
       !hasTrailingComment(key.content) &&
-      (!parentNode.tag || parentNode.tag.value !== "tag:yaml.org,2002:set")
+      parent.tag?.value !== "tag:yaml.org,2002:set"
     ) {
       return [printedKey, spaceBeforeColon, ":"];
     }
@@ -60,12 +60,7 @@ function printMappingItem(node, parentNode, path, print, options) {
       "? ",
       alignWithSpaces(2, printedKey),
       hardline,
-      join(
-        "",
-        path
-          .map(print, "value", "leadingComments")
-          .map((comment) => [comment, hardline])
-      ),
+      ...path.map(() => [print(), hardline], "value", "leadingComments"),
       ": ",
       alignWithSpaces(2, printedValue),
     ];
@@ -107,7 +102,7 @@ function printMappingItem(node, parentNode, path, print, options) {
     (hasEndComments(value) &&
       value.content &&
       !isNode(value.content, ["mapping", "sequence"])) ||
-    (parentNode.type === "mapping" &&
+    (parent.type === "mapping" &&
       hasTrailingComment(key.content) &&
       isInlineNode(value.content)) ||
     (isNode(value.content, ["mapping", "sequence"]) &&

src/language-yaml/print/misc.js

@@ -3,8 +3,7 @@ import { hasEndComments, isNextLineEmpty, isNode } from "../utils.js";
 
 const printedEmptyLineCache = new WeakMap();
 function printNextEmptyLine(path, originalText) {
-  const { node } = path;
-  const root = path.stack[0];
+  const { node, root } = path;
 
   let isNextEmptyLinePrintedSet;
   if (printedEmptyLineCache.has(root)) {

src/language-yaml/printer-yaml.js

@@ -98,7 +98,6 @@ function genericPrint(path, options, print) {
     ]);
   }
 
-  const parentNode = path.getParentNode();
   if (hasPrettierIgnore(path)) {
     parts.push(
       replaceEndOfLine(
@@ -108,14 +107,14 @@ function genericPrint(path, options, print) {
       )
     );
   } else {
-    parts.push(group(printNode(node, parentNode, path, options, print)));
+    parts.push(group(printNode(path, options, print)));
   }
 
   if (hasTrailingComment(node) && !isNode(node, ["document", "documentHead"])) {
     parts.push(
       lineSuffix([
         node.type === "mappingValue" && !node.content ? "" : " ",
-        parentNode.type === "mappingKey" &&
+        path.parent.type === "mappingKey" &&
         path.getParentNode(2).type === "mapping" &&
         isInlineNode(node)
           ? ""
@@ -132,8 +131,8 @@ function genericPrint(path, options, print) {
         join(
           hardline,
           path.map(
-            (path) => [
-              isPreviousLineEmpty(options.originalText, path.node, locStart)
+            ({ node }) => [
+              isPreviousLineEmpty(options.originalText, node, locStart)
                 ? hardline
                 : "",
               print(),
@@ -148,15 +147,13 @@ function genericPrint(path, options, print) {
   return parts;
 }
 
-function printNode(node, parentNode, path, options, print) {
+function printNode(path, options, print) {
+  const { node } = path;
   switch (node.type) {
     case "root": {
-      const { children } = node;
       const parts = [];
-      path.each((childPath, index) => {
-        const document = children[index];
-        const nextDocument = children[index + 1];
-        if (index !== 0) {
+      path.each(({ node: document, next: nextDocument, isFirst }) => {
+        if (!isFirst) {
           parts.push(hardline);
         }
         parts.push(print());
@@ -180,16 +177,8 @@ function printNode(node, parentNode, path, options, print) {
       return parts;
     }
     case "document": {
-      const nextDocument = parentNode.children[path.getName() + 1];
       const parts = [];
-      if (
-        shouldPrintDocumentHeadEndMarker(
-          node,
-          nextDocument,
-          parentNode,
-          options
-        ) === "head"
-      ) {
+      if (shouldPrintDocumentHeadEndMarker(path, options) === "head") {
         if (node.head.children.length > 0 || node.head.endComments.length > 0) {
           parts.push(print("head"));
         }
@@ -331,7 +320,7 @@ function printNode(node, parentNode, path, options, print) {
       return !node.content ? "" : print("content");
     case "mappingItem":
     case "flowMappingItem":
-      return printMappingItem(node, parentNode, path, print, options);
+      return printMappingItem(path, print, options);
 
     case "flowMapping":
       return printFlowMapping(path, print, options);
@@ -371,18 +360,14 @@ function shouldPrintDocumentEndMarker(document, nextDocument) {
   );
 }
 
-function shouldPrintDocumentHeadEndMarker(
-  document,
-  nextDocument,
-  root,
-  options
-) {
+function shouldPrintDocumentHeadEndMarker(path, options) {
+  const document = path.node;
   if (
     /**
      * ---
      * preserve the first document head end marker
      */
-    (root.children[0] === document &&
+    (path.isFirst &&
       /---(?:\s|$)/.test(
         options.originalText.slice(locStart(document), locStart(document) + 4)
       )) ||
@@ -404,6 +389,7 @@ function shouldPrintDocumentHeadEndMarker(
     return "head";
   }
 
+  const nextDocument = path.next;
   if (shouldPrintDocumentEndMarker(document, nextDocument)) {
     return false;
   }

src/language-yaml/utils.js

@@ -109,10 +109,10 @@ function hasPrettierIgnore(path) {
   const { node } = path;
 
   if (node.type === "documentBody") {
-    const document = path.getParentNode();
+    const documentHead = path.parent.head;
     return (
-      hasEndComments(document.head) &&
-      isPrettierIgnore(document.head.endComments.at(-1))
+      hasEndComments(documentHead) &&
+      isPrettierIgnore(documentHead.endComments.at(-1))
     );
   }