From db2bc3636dd27df62f80f7ec4ec04eb44640b29c Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Sat, 1 Sep 2018 20:04:37 +0800
Subject: [PATCH] fix(yaml): update parsers (#5027)

- upgrade to `yaml@1.0.0-rc.8` and `yaml-unist-parser@1.0.0-rc.4`
- refactor some logic since the AST has slightly changed (ikatyang/yaml-unist-parser#82)
- unmatched aliases are now errors since it may introduce invalid AST from `yaml`
- rewrite the document separator (`...`/`---`) logic, this fixes some cases where it can use `---` but we printed `...`
- removed some unnecessary duplicate trailing newline
- trailing comments on `document` (`... #comment`) and `documentHead` (`--- #comment`) are preserved (i.e. they won't be moved somewhere)
---
 package.json                                  |   4 +-
 .../replace-array-includes-with-indexof.js    |   4 +-
 scripts/build/build.js                        |   2 +-
 src/language-yaml/parser-yaml.js              |  27 +-
 src/language-yaml/printer-yaml.js             | 366 +++++++++++-------
 src/language-yaml/utils.js                    |  86 ++--
 .../__snapshots__/jsfmt.spec.js.snap          |   6 +-
 tests/yaml_alias/common.yml                   |   3 +-
 .../__snapshots__/jsfmt.spec.js.snap          |   3 +-
 .../__snapshots__/jsfmt.spec.js.snap          |  45 ++-
 tests/yaml_flow_mapping/alias-key.yml         |   2 +-
 tests/yaml_flow_mapping/very-long-value.yml   |   3 +
 .../__snapshots__/jsfmt.spec.js.snap          |  12 +-
 tests/yaml_flow_sequence/alias-key.yml        |   2 +-
 .../__snapshots__/jsfmt.spec.js.snap          |   2 +-
 .../__snapshots__/jsfmt.spec.js.snap          |  14 +-
 yarn.lock                                     |  16 +-
 17 files changed, 341 insertions(+), 256 deletions(-)
 create mode 100644 tests/yaml_flow_mapping/very-long-value.yml

diff --git a/package.json b/package.json
index 5b185800b55b..13845cb99548 100644
--- a/package.json
+++ b/package.json
@@ -62,8 +62,8 @@
     "unicode-regex": "1.0.1",
     "unified": "6.1.6",
     "vnopts": "1.0.2",
-    "yaml": "ikatyang/yaml#a765c1ee16d6b8a5e715564645f2b85f7e04828b",
-    "yaml-unist-parser": "ikatyang/yaml-unist-parser#cd4f73325b3fc02a6d17842d0d9cee0dfc729c9b"
+    "yaml": "1.0.0-rc.8",
+    "yaml-unist-parser": "1.0.0-rc.4"
   },
   "devDependencies": {
     "@babel/cli": "7.0.0-beta.55",
diff --git a/scripts/build/babel-plugins/replace-array-includes-with-indexof.js b/scripts/build/babel-plugins/replace-array-includes-with-indexof.js
index c76ff88578be..18514344b78a 100644
--- a/scripts/build/babel-plugins/replace-array-includes-with-indexof.js
+++ b/scripts/build/babel-plugins/replace-array-includes-with-indexof.js
@@ -19,7 +19,9 @@ module.exports = ({ types: t }) => ({
         t.isMemberExpression(callee, { computed: false }) &&
         (t.isArrayExpression(callee.object) ||
           (t.isIdentifier(callee.object) &&
-            /^[A-Z_]+$/.test(callee.object.name))) &&
+            (/^[A-Z_]+$/.test(callee.object.name) ||
+              // https://github.com/eemeli/yaml/blob/1005d01/src/Anchors.js#L45
+              callee.object.name === "names"))) &&
         t.isIdentifier(callee.property, { name: "includes" })
       ) {
         callee.property.name = "indexOf";
diff --git a/scripts/build/build.js b/scripts/build/build.js
index f2e659842d43..3029f1b33ad8 100644
--- a/scripts/build/build.js
+++ b/scripts/build/build.js
@@ -98,7 +98,7 @@ async function run(params) {
     await execa("rm", ["-rf", ".cache"]);
   }
 
-  const bundleCache = new Cache(".cache/", "v5");
+  const bundleCache = new Cache(".cache/", "v6");
   await bundleCache.load();
 
   console.log(chalk.inverse(" Building packages "));
diff --git a/src/language-yaml/parser-yaml.js b/src/language-yaml/parser-yaml.js
index a3ba4f204105..1a5313e5065c 100644
--- a/src/language-yaml/parser-yaml.js
+++ b/src/language-yaml/parser-yaml.js
@@ -2,7 +2,7 @@
 
 const createError = require("../common/parser-create-error");
 const { hasPragma } = require("./pragma");
-const { createNull, defineShortcut, mapNode } = require("./utils");
+const { defineShortcut, mapNode } = require("./utils");
 
 function defineShortcuts(node) {
   switch (node.type) {
@@ -10,11 +10,12 @@ function defineShortcuts(node) {
       defineShortcut(node, "head", () => node.children[0]);
       defineShortcut(node, "body", () => node.children[1]);
       break;
+    case "documentBody":
     case "sequenceItem":
     case "flowSequenceItem":
     case "mappingKey":
     case "mappingValue":
-      defineShortcut(node, "node", () => node.children[0]);
+      defineShortcut(node, "content", () => node.children[0]);
       break;
     case "mappingItem":
     case "flowMappingItem":
@@ -22,25 +23,15 @@ function defineShortcuts(node) {
       defineShortcut(node, "value", () => node.children[1]);
       break;
   }
+  return node;
 }
 
 function parse(text) {
   try {
-    const root = mapNode(require("yaml-unist-parser").parse(text), node => {
-      // replace explicit empty MappingKey/MappingValue with implicit one
-      if (
-        (node.type === "mappingKey" || node.type === "mappingValue") &&
-        node.children[0].type === "null" &&
-        node.leadingComments.length === 0 &&
-        node.trailingComments.length === 0 &&
-        node.endComments.length === 0
-      ) {
-        return createNull();
-      }
-
-      defineShortcuts(node);
-      return node;
-    });
+    const root = mapNode(
+      require("yaml-unist-parser").parse(text),
+      defineShortcuts
+    );
 
     /**
      * suppress `comment not printed` error
@@ -53,7 +44,7 @@ function parse(text) {
     return root;
   } catch (error) {
     // istanbul ignore next
-    throw error && error.name === "YAMLSyntaxError"
+    throw error && error.position
       ? createError(error.message, error.position)
       : error;
   }
diff --git a/src/language-yaml/printer-yaml.js b/src/language-yaml/printer-yaml.js
index d2e403c1a7cb..420e69459d40 100644
--- a/src/language-yaml/printer-yaml.js
+++ b/src/language-yaml/printer-yaml.js
@@ -7,16 +7,16 @@ const {
   getFlowScalarLineContents,
   getLast,
   getLastDescendantNode,
-  hasExplicitDocumentEndMarker,
   hasLeadingComments,
   hasMiddleComments,
-  hasTrailingComments,
+  hasIndicatorComment,
+  hasTrailingComment,
   hasEndComments,
   hasPrettierIgnore,
   isLastDescendantNode,
   isNextLineEmpty,
   isNode,
-  isBlockValue
+  isEmptyNode
 } = require("./utils");
 const docBuilders = require("../doc").builders;
 const {
@@ -41,22 +41,18 @@ function genericPrint(path, options, print) {
   const node = path.getValue();
   const parentNode = path.getParentNode();
 
-  const tag =
-    "tag" in node && node.tag.type !== "null" ? path.call(print, "tag") : "";
-
-  const anchor =
-    "anchor" in node && node.anchor.type !== "null"
-      ? path.call(print, "anchor")
-      : "";
+  const tag = !node.tag ? "" : path.call(print, "tag");
+  const anchor = !node.anchor ? "" : path.call(print, "anchor");
 
   const nextEmptyLine =
-    (node.type === "mapping" ||
-      node.type === "sequence" ||
-      node.type === "comment" ||
-      node.type === "directive" ||
-      node.type === "mappingItem" ||
-      node.type === "sequenceItem") &&
-    !isLastDescendantNode(path)
+    isNode(node, [
+      "mapping",
+      "sequence",
+      "comment",
+      "directive",
+      "mappingItem",
+      "sequenceItem"
+    ]) && !isLastDescendantNode(path)
       ? printNextEmptyLine(path, options.originalText)
       : "";
 
@@ -67,14 +63,11 @@ function genericPrint(path, options, print) {
     tag,
     tag && anchor ? " " : "",
     anchor,
-    (node.type === "sequence" || node.type === "mapping") &&
-    node.middleComments.length === 0
-      ? tag || anchor
+    tag || anchor
+      ? isNode(node, ["sequence", "mapping"]) && !hasMiddleComments(node)
         ? hardline
-        : ""
-      : tag || anchor
-        ? " "
-        : "",
+        : " "
+      : "",
     hasMiddleComments(node)
       ? concat([
           node.middleComments.length === 1 ? "" : hardline,
@@ -88,23 +81,23 @@ function genericPrint(path, options, print) {
           node.position.end.offset
         )
       : group(_print(node, parentNode, path, options, print)),
-    !isBlockValue(node) && hasTrailingComments(node) // trailing comments for block value are handled themselves
+    hasTrailingComment(node) && !isNode(node, ["document", "documentHead"])
       ? lineSuffix(
           concat([
-            " ",
+            node.type === "mappingValue" && !node.content ? "" : " ",
             parentNode.type === "mappingKey" &&
             path.getParentNode(2).type === "mapping" &&
             isInlineNode(node)
               ? ""
               : breakParent,
-            join(hardline, path.map(print, "trailingComments"))
+            path.call(print, "trailingComment")
           ])
         )
       : "",
     nextEmptyLine,
-    hasEndComments(node)
-      ? (endComments =>
-          node.type === "sequenceItem" ? align(2, endComments) : endComments)(
+    hasEndComments(node) && !isNode(node, ["documentHead", "documentBody"])
+      ? align(
+          node.type === "sequenceItem" ? 2 : 0,
           concat([hardline, join(hardline, path.map(print, "endComments"))])
         )
       : ""
@@ -115,67 +108,95 @@ function _print(node, parentNode, path, options, print) {
   switch (node.type) {
     case "root":
       return concat([
-        concat(
-          path.map(
-            (childPath, index) =>
-              index === node.children.length - 1
-                ? print(childPath)
-                : concat([
-                    print(childPath),
-                    hasTrailingComments(node.children[index]) ||
-                    (childPath.call(hasPrettierIgnore, "body") &&
-                      hasExplicitDocumentEndMarker(
-                        node.children[index],
-                        options.originalText
-                      ))
-                      ? ""
-                      : concat([
-                          hardline,
-                          node.children[index + 1].head.children.length === 0
-                            ? "---"
-                            : "..."
-                        ]),
-                    hardline
-                  ]),
-            "children"
-          )
+        join(
+          hardline,
+          path.map((childPath, index) => {
+            const document = node.children[index];
+            const nextDocument = node.children[index + 1];
+            return concat([
+              print(childPath),
+              shouldPrintDocumentEndMarker(document, nextDocument)
+                ? concat([
+                    hardline,
+                    "...",
+                    hasTrailingComment(document)
+                      ? concat([" ", path.call(print, "trailingComment")])
+                      : ""
+                  ])
+                : !nextDocument || hasTrailingComment(nextDocument.head)
+                  ? ""
+                  : concat([hardline, "---"])
+            ]);
+          }, "children")
         ),
         node.children.length === 0 ||
         (lastDescendantNode =>
-          isBlockValue(lastDescendantNode) &&
+          isNode(lastDescendantNode, ["blockLiteral", "blockFolded"]) &&
           lastDescendantNode.chomping === "keep")(getLastDescendantNode(node))
           ? ""
           : hardline
       ]);
-    case "document":
-      return concat([
-        node.head.children.length === 0
-          ? path.call(print, "body")
-          : join(
-              hardline,
-              [path.call(print, "head"), "---"].concat(
-                node.body.children.length === 0 ? [] : path.call(print, "body")
+    case "document": {
+      const nextDocument = parentNode.children[path.getName() + 1];
+      return join(
+        hardline,
+        [
+          shouldPrintDocumentHeadEndMarker(node, nextDocument) === "head"
+            ? join(
+                hardline,
+                [
+                  node.head.children.length === 0 &&
+                  node.head.endComments.length === 0
+                    ? ""
+                    : path.call(print, "head"),
+                  concat([
+                    "---",
+                    hasTrailingComment(node.head)
+                      ? concat([
+                          " ",
+                          path.call(print, "head", "trailingComment")
+                        ])
+                      : ""
+                  ])
+                ].filter(Boolean)
               )
-            ),
-        hasTrailingComments(node) ? concat([hardline, "..."]) : ""
-      ]);
+            : "",
+          shouldPrintDocumentBody(node) ? path.call(print, "body") : ""
+        ].filter(Boolean)
+      );
+    }
     case "documentHead":
-    case "documentBody":
-      return join(hardline, path.map(print, "children"));
+      return join(
+        hardline,
+        [].concat(path.map(print, "children"), path.map(print, "endComments"))
+      );
+    case "documentBody": {
+      const children = join(hardline, path.map(print, "children")).parts;
+      const endComments = join(hardline, path.map(print, "endComments")).parts;
+      const separator =
+        children.length === 0 || endComments.length === 0
+          ? ""
+          : (lastDescendantNode =>
+              isNode(lastDescendantNode, ["blockFolded", "blockLiteral"])
+                ? lastDescendantNode.chomping === "keep"
+                  ? // there's already a newline printed at the end of blockValue (chomping=keep, lastDescendant=true)
+                    ""
+                  : // an extra newline for better readability
+                    concat([hardline, hardline])
+                : hardline)(getLastDescendantNode(node));
+      return concat([].concat(children, separator, endComments));
+    }
     case "directive":
       return concat(["%", join(" ", [node.name].concat(node.parameters))]);
     case "comment":
       return concat(["#", node.value]);
     case "alias":
       return concat(["*", node.value]);
-    case "null":
-      return "";
-    case "verbatimTag":
-      return concat(["!<", node.value, ">"]);
-    case "shorthandTag":
-      return concat([node.handle, node.suffix]);
-    case "nonSpecificTag":
-      return "!";
+    case "tag":
+      return options.originalText.slice(
+        node.position.start.offset,
+        node.position.end.offset
+      );
     case "anchor":
       return concat(["&", node.value]);
     case "plain":
@@ -249,18 +270,16 @@ function _print(node, parentNode, path, options, print) {
     }
     case "blockFolded":
     case "blockLiteral": {
-      const parentIndent = getAncestorCount(
-        path,
-        ancestorNode =>
-          ancestorNode.type === "sequence" || ancestorNode.type === "mapping"
+      const parentIndent = getAncestorCount(path, ancestorNode =>
+        isNode(ancestorNode, ["sequence", "mapping"])
       );
       const isLastDescendant = isLastDescendantNode(path);
       return concat([
         node.type === "blockFolded" ? ">" : "|",
         node.indent === null ? "" : node.indent.toString(),
         node.chomping === "clip" ? "" : node.chomping === "keep" ? "+" : "-",
-        hasTrailingComments(node)
-          ? concat([" ", join(hardline, path.map(print, "trailingComments"))])
+        hasIndicatorComment(node)
+          ? concat([" ", path.call(print, "indicatorComment")])
           : "",
         (node.indent === null ? dedent : dedentToRoot)(
           align(
@@ -275,23 +294,17 @@ function _print(node, parentNode, path, options, print) {
               }).reduce(
                 (reduced, lineWords, index, lineContents) =>
                   reduced.concat(
-                    index === 0
-                      ? hardline
-                      : lineContents[index - 1].length === 0
-                        ? hardline
-                        : index === lineContents.length - 1 &&
-                          lineWords.length === 0
-                          ? dedentToRoot(literalline)
-                          : markAsRoot(literalline),
+                    index === 0 ? hardline : "",
                     fill(join(line, lineWords).parts),
-                    index === lineContents.length - 1 &&
-                    node.chomping === "keep" &&
-                    isLastDescendant
-                      ? lineWords.length === 0 ||
-                        !getLast(lineWords).endsWith(" ")
-                        ? dedentToRoot(hardline)
-                        : dedentToRoot(literalline)
-                      : []
+                    index !== lineContents.length - 1
+                      ? lineWords.length === 0
+                        ? hardline
+                        : markAsRoot(literalline)
+                      : node.chomping === "keep" && isLastDescendant
+                        ? lineWords.length === 0
+                          ? dedentToRoot(hardline)
+                          : dedentToRoot(literalline)
+                        : ""
                   ),
                 []
               )
@@ -303,35 +316,37 @@ function _print(node, parentNode, path, options, print) {
     case "sequence":
       return join(hardline, path.map(print, "children"));
     case "sequenceItem":
-      return concat(["- ", align(2, path.call(print, "node"))]);
+      return concat([
+        "- ",
+        align(2, !node.content ? "" : path.call(print, "content"))
+      ]);
     case "mappingKey":
-      return path.call(print, "node");
+      return !node.content ? "" : path.call(print, "content");
     case "mappingValue":
-      return path.call(print, "node");
+      return !node.content ? "" : path.call(print, "content");
     case "mapping":
       return join(hardline, path.map(print, "children"));
     case "mappingItem":
     case "flowMappingItem": {
-      if (node.key.type === "null" && node.value.type === "null") {
-        return concat([":", line]);
+      const isEmptyMappingKey = isEmptyNode(node.key);
+      const isEmptyMappingValue = isEmptyNode(node.value);
+
+      if (isEmptyMappingKey && isEmptyMappingValue) {
+        return concat([": "]);
       }
 
       const key = path.call(print, "key");
       const value = path.call(print, "value");
 
-      if (node.value.type === "null") {
+      if (isEmptyMappingValue) {
         return node.type === "flowMappingItem" &&
-          path.getParentNode().type !== "flowSequence"
+          parentNode.type === "flowMapping"
           ? key
           : node.type === "mappingItem" &&
-            node.key.type !== "null" &&
-            isAbsolutelyPrintedAsSingleLineNode(node.key.node, options) &&
-            !hasTrailingComments(node.key.node) &&
-            !(
-              parentNode.tag.type === "shorthandTag" &&
-              parentNode.tag.handle === "!!" &&
-              parentNode.tag.suffix === "set"
-            )
+            isAbsolutelyPrintedAsSingleLineNode(node.key.content, options) &&
+            !hasTrailingComment(node.key.content) &&
+            (!parentNode.tag ||
+              parentNode.tag.value !== "tag:yaml.org,2002:set")
             ? concat([
                 key,
                 needsSpaceInFrontOfMappingValue(node) ? " " : "",
@@ -340,19 +355,15 @@ function _print(node, parentNode, path, options, print) {
             : concat(["? ", align(2, key)]);
       }
 
-      if (node.key.type === "null") {
-        return concat([
-          ":",
-          node.value.node.type === "null" ? "" : " ",
-          align(2, value)
-        ]);
+      if (isEmptyMappingKey) {
+        return concat([": ", align(2, value)]);
       }
 
       const groupId = Symbol("mappingKey");
 
       const forceExplicitKey =
-        hasLeadingComments(node.value) ||
-        (node.key.type !== "null" && !isInlineNode(node.key.node));
+        hasLeadingComments(node.value) || !isInlineNode(node.key.content);
+
       return forceExplicitKey
         ? concat([
             "? ",
@@ -368,15 +379,15 @@ function _print(node, parentNode, path, options, print) {
             align(2, value)
           ])
         : // force singleline
-          isSingleLineNode(node.key.node) &&
-          !hasLeadingComments(node.key.node) &&
-          !hasMiddleComments(node.key.node) &&
-          !hasTrailingComments(node.key.node) &&
+          isSingleLineNode(node.key.content) &&
+          !hasLeadingComments(node.key.content) &&
+          !hasMiddleComments(node.key.content) &&
+          !hasTrailingComment(node.key.content) &&
           !hasEndComments(node.key) &&
-          !hasLeadingComments(node.value.node) &&
-          !hasMiddleComments(node.value.node) &&
+          !hasLeadingComments(node.value.content) &&
+          !hasMiddleComments(node.value.content) &&
           !hasEndComments(node.value) &&
-          isAbsolutelyPrintedAsSingleLineNode(node.value.node, options)
+          isAbsolutelyPrintedAsSingleLineNode(node.value.content, options)
           ? concat([
               key,
               needsSpaceInFrontOfMappingValue(node) ? " " : "",
@@ -394,18 +405,18 @@ function _print(node, parentNode, path, options, print) {
                     concat([
                       needsSpaceInFrontOfMappingValue(node) ? " " : "",
                       ":",
-                      hasLeadingComments(node.value.node) ||
+                      hasLeadingComments(node.value.content) ||
                       (hasEndComments(node.value) &&
-                        node.value.node.type !== "null") ||
+                        node.value.content &&
+                        !isNode(node.value.content, ["mapping", "sequence"])) ||
                       (parentNode.type === "mapping" &&
-                        hasTrailingComments(node.key.node) &&
-                        isInlineNode(node.value.node)) ||
-                      ((node.value.node.type === "mapping" ||
-                        node.value.node.type === "sequence") &&
-                        node.value.node.tag.type === "null" &&
-                        node.value.node.anchor.type === "null")
+                        hasTrailingComment(node.key.content) &&
+                        isInlineNode(node.value.content)) ||
+                      (isNode(node.value.content, ["mapping", "sequence"]) &&
+                        node.value.content.tag === null &&
+                        node.value.content.anchor === null)
                         ? hardline
-                        : node.value.node.type === "null"
+                        : !node.value.content
                           ? ""
                           : line,
                       value
@@ -430,8 +441,8 @@ function _print(node, parentNode, path, options, print) {
         node.children.length !== 0 &&
         (lastItem =>
           lastItem.type === "flowMappingItem" &&
-          lastItem.key.type === "null" &&
-          lastItem.value.type === "null")(getLast(node.children));
+          isEmptyNode(lastItem.key) &&
+          isEmptyNode(lastItem.value))(getLast(node.children));
       return concat([
         openMarker,
         indent(
@@ -467,7 +478,7 @@ function _print(node, parentNode, path, options, print) {
       ]);
     }
     case "flowSequenceItem":
-      return path.call(print, "node");
+      return path.call(print, "content");
     // istanbul ignore next
     default:
       throw new Error(`Unexpected node type ${node.type}`);
@@ -485,6 +496,10 @@ function align(n, doc) {
 }
 
 function isInlineNode(node) {
+  if (!node) {
+    return true;
+  }
+
   switch (node.type) {
     case "plain":
     case "quoteDouble":
@@ -492,7 +507,6 @@ function isInlineNode(node) {
     case "alias":
     case "flowMapping":
     case "flowSequence":
-    case "null":
       return true;
     default:
       return false;
@@ -500,6 +514,10 @@ function isInlineNode(node) {
 }
 
 function isSingleLineNode(node) {
+  if (!node) {
+    return true;
+  }
+
   switch (node.type) {
     case "plain":
     case "quoteDouble":
@@ -512,7 +530,64 @@ function isSingleLineNode(node) {
   }
 }
 
+function shouldPrintDocumentBody(document) {
+  return document.body.children.length !== 0 || hasEndComments(document.body);
+}
+
+function shouldPrintDocumentEndMarker(document, nextDocument) {
+  return (
+    /**
+     *... # trailingComment
+     */
+    hasTrailingComment(document) ||
+    (nextDocument &&
+      /**
+       * ...
+       * %DIRECTIVE
+       * ---
+       */
+      (nextDocument.head.children.length !== 0 ||
+        /**
+         * ...
+         * # endComment
+         * ---
+         */
+        hasEndComments(nextDocument.head)))
+  );
+}
+
+function shouldPrintDocumentHeadEndMarker(document, nextDocument) {
+  if (
+    /**
+     * %DIRECTIVE
+     * ---
+     */
+    document.head.children.length !== 0 ||
+    /**
+     * # end comment
+     * ---
+     */
+    hasEndComments(document.head) ||
+    /**
+     * --- # trailing comment
+     */
+    hasTrailingComment(document.head)
+  ) {
+    return "head";
+  }
+
+  if (shouldPrintDocumentEndMarker(document, nextDocument)) {
+    return false;
+  }
+
+  return nextDocument ? "root" : false;
+}
+
 function isAbsolutelyPrintedAsSingleLineNode(node, options) {
+  if (!node) {
+    return true;
+  }
+
   switch (node.type) {
     case "plain":
     case "quoteSingle":
@@ -552,14 +627,7 @@ function isAbsolutelyPrintedAsSingleLineNode(node, options) {
 }
 
 function needsSpaceInFrontOfMappingValue(node) {
-  // istanbul ignore else
-  if (node.key.type !== "null") {
-    switch (node.key.node.type) {
-      case "alias":
-        return true;
-    }
-  }
-  return false;
+  return node.key.content && node.key.content.type === "alias";
 }
 
 function printNextEmptyLine(path, originalText) {
diff --git a/src/language-yaml/utils.js b/src/language-yaml/utils.js
index e0cf6c8cd33f..dbaca57dda04 100644
--- a/src/language-yaml/utils.js
+++ b/src/language-yaml/utils.js
@@ -16,8 +16,16 @@ function getAncestorCount(path, filter) {
   return counter;
 }
 
-function isNode(value) {
-  return value && typeof value.type === "string";
+/**
+ * @param {any} value
+ * @param {string[]=} types
+ */
+function isNode(value, types) {
+  return (
+    value &&
+    typeof value.type === "string" &&
+    (!types || types.indexOf(value.type) !== -1)
+  );
 }
 
 function mapNode(node, callback, parent) {
@@ -40,16 +48,6 @@ function defineShortcut(x, key, getter) {
   });
 }
 
-function createNull() {
-  return {
-    type: "null",
-    position: {
-      start: { line: -1, column: -1, offset: -1 },
-      end: { line: -1, column: -1, offset: -1 }
-    }
-  };
-}
-
 function isNextLineEmpty(node, text) {
   let newlineCount = 0;
   const textLength = text.length;
@@ -76,12 +74,12 @@ function isLastDescendantNode(path) {
   const node = path.getValue();
 
   switch (node.type) {
+    case "tag":
+    case "anchor":
     case "comment":
-    case "verbatimTag":
-    case "shorthandTag":
-    case "nonSpecificTag":
       return false;
   }
+
   const pathStackLength = path.stack.length;
 
   for (let i = 1; i < pathStackLength; i++) {
@@ -116,53 +114,48 @@ function hasPrettierIgnore(path) {
   if (node.type === "documentBody") {
     const document = path.getParentNode();
     return (
-      document.head.children.length !== 0 &&
-      (lastItem => lastItem.type === "comment" && isPrettierIgnore(lastItem))(
-        getLast(document.head.children)
-      )
+      hasEndComments(document.head) &&
+      isPrettierIgnore(getLast(document.head.endComments))
     );
   }
 
   return (
-    "leadingComments" in node &&
-    node.leadingComments.length !== 0 &&
-    isPrettierIgnore(getLast(node.leadingComments))
+    hasLeadingComments(node) && isPrettierIgnore(getLast(node.leadingComments))
   );
 }
 
-function hasExplicitDocumentEndMarker(document, text) {
-  return (
-    text.slice(
-      document.position.end.offset - 4,
-      document.position.end.offset
-    ) === "\n..."
-  );
+function isEmptyNode(node) {
+  return (!node.children || node.children.length === 0) && !hasComments(node);
 }
 
-function isBlockValue(node) {
-  switch (node.type) {
-    case "blockFolded":
-    case "blockLiteral":
-      return true;
-    default:
-      return false;
-  }
+function hasComments(node) {
+  return (
+    hasLeadingComments(node) ||
+    hasMiddleComments(node) ||
+    hasIndicatorComment(node) ||
+    hasTrailingComment(node) ||
+    hasEndComments(node)
+  );
 }
 
 function hasLeadingComments(node) {
-  return "leadingComments" in node && node.leadingComments.length !== 0;
+  return node && node.leadingComments && node.leadingComments.length !== 0;
 }
 
 function hasMiddleComments(node) {
-  return "middleComments" in node && node.middleComments.length !== 0;
+  return node && node.middleComments && node.middleComments.length !== 0;
+}
+
+function hasIndicatorComment(node) {
+  return node && node.indicatorComment;
 }
 
-function hasTrailingComments(node) {
-  return "trailingComments" in node && node.trailingComments.length !== 0;
+function hasTrailingComment(node) {
+  return node && node.trailingComment;
 }
 
 function hasEndComments(node) {
-  return "endComments" in node && node.endComments.length !== 0;
+  return node && node.endComments && node.endComments.length !== 0;
 }
 
 /**
@@ -337,10 +330,9 @@ module.exports = {
   getLast,
   getAncestorCount,
   isNode,
-  isBlockValue,
+  isEmptyNode,
   mapNode,
   defineShortcut,
-  createNull,
   isNextLineEmpty,
   isLastDescendantNode,
   getBlockValueLineContents,
@@ -349,7 +341,7 @@ module.exports = {
   hasPrettierIgnore,
   hasLeadingComments,
   hasMiddleComments,
-  hasTrailingComments,
-  hasEndComments,
-  hasExplicitDocumentEndMarker
+  hasIndicatorComment,
+  hasTrailingComment,
+  hasEndComments
 };
diff --git a/tests/yaml_alias/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_alias/__snapshots__/jsfmt.spec.js.snap
index d36639ccd084..636491148eb1 100644
--- a/tests/yaml_alias/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_alias/__snapshots__/jsfmt.spec.js.snap
@@ -1,8 +1,10 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`common.yml - yaml-verify 1`] = `
-*abc
+- &abc a
+- *abc
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-*abc
+- &abc a
+- *abc
 
 `;
diff --git a/tests/yaml_alias/common.yml b/tests/yaml_alias/common.yml
index cd06d36f1807..c1687c2e837f 100644
--- a/tests/yaml_alias/common.yml
+++ b/tests/yaml_alias/common.yml
@@ -1 +1,2 @@
-*abc
+- &abc a
+- *abc
diff --git a/tests/yaml_document/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_document/__snapshots__/jsfmt.spec.js.snap
index 4f02bd829e6f..b6bb97a74d74 100644
--- a/tests/yaml_document/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_document/__snapshots__/jsfmt.spec.js.snap
@@ -50,8 +50,7 @@ e
 #
 ---
 f
----
-#
+--- #
 g
 
 `;
diff --git a/tests/yaml_flow_mapping/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_flow_mapping/__snapshots__/jsfmt.spec.js.snap
index d182a8615c18..2251c5a1862a 100644
--- a/tests/yaml_flow_mapping/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_flow_mapping/__snapshots__/jsfmt.spec.js.snap
@@ -1,23 +1,23 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`alias-key.yml - yaml-verify 1`] = `
-{*123 : 456}
+{&123 foo, *123 : 456}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-{ *123 : 456 }
+{ &123 foo, *123 : 456 }
 
 `;
 
 exports[`alias-key.yml - yaml-verify 2`] = `
-{*123 : 456}
+{&123 foo, *123 : 456}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-{ *123 : 456 }
+{ &123 foo, *123 : 456 }
 
 `;
 
 exports[`alias-key.yml - yaml-verify 3`] = `
-{*123 : 456}
+{&123 foo, *123 : 456}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-{*123 : 456}
+{&123 foo, *123 : 456}
 
 `;
 
@@ -902,3 +902,36 @@ exports[`short-value.yml - yaml-verify 3`] = `
 {1: 1, 2: 2, 3: 3}
 
 `;
+
+exports[`very-long-value.yml - yaml-verify 1`] = `
+{
+x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+{
+  x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890,
+}
+
+`;
+
+exports[`very-long-value.yml - yaml-verify 2`] = `
+{
+x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+{
+    x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890,
+}
+
+`;
+
+exports[`very-long-value.yml - yaml-verify 3`] = `
+{
+x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+{
+  x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890,
+}
+
+`;
diff --git a/tests/yaml_flow_mapping/alias-key.yml b/tests/yaml_flow_mapping/alias-key.yml
index ab4a8d77022a..fa510b20255e 100644
--- a/tests/yaml_flow_mapping/alias-key.yml
+++ b/tests/yaml_flow_mapping/alias-key.yml
@@ -1 +1 @@
-{*123 : 456}
+{&123 foo, *123 : 456}
diff --git a/tests/yaml_flow_mapping/very-long-value.yml b/tests/yaml_flow_mapping/very-long-value.yml
new file mode 100644
index 000000000000..c93ac873696d
--- /dev/null
+++ b/tests/yaml_flow_mapping/very-long-value.yml
@@ -0,0 +1,3 @@
+{
+x: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
+}
diff --git a/tests/yaml_flow_sequence/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_flow_sequence/__snapshots__/jsfmt.spec.js.snap
index 9c4635c9bec4..fb98eea4f269 100644
--- a/tests/yaml_flow_sequence/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_flow_sequence/__snapshots__/jsfmt.spec.js.snap
@@ -1,23 +1,23 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`alias-key.yml - yaml-verify 1`] = `
-[*123 : 456]
+[&123 foo, *123 : 456]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-[*123 : 456]
+[&123 foo, *123 : 456]
 
 `;
 
 exports[`alias-key.yml - yaml-verify 2`] = `
-[*123 : 456]
+[&123 foo, *123 : 456]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-[*123 : 456]
+[&123 foo, *123 : 456]
 
 `;
 
 exports[`alias-key.yml - yaml-verify 3`] = `
-[*123 : 456]
+[&123 foo, *123 : 456]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-[*123 : 456]
+[&123 foo, *123 : 456]
 
 `;
 
diff --git a/tests/yaml_flow_sequence/alias-key.yml b/tests/yaml_flow_sequence/alias-key.yml
index 9241a61bff95..c9c6174124b9 100644
--- a/tests/yaml_flow_sequence/alias-key.yml
+++ b/tests/yaml_flow_sequence/alias-key.yml
@@ -1 +1 @@
-[*123 : 456]
+[&123 foo, *123 : 456]
diff --git a/tests/yaml_prettier_ignore/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_prettier_ignore/__snapshots__/jsfmt.spec.js.snap
index 1b42cf42541e..840655368560 100644
--- a/tests/yaml_prettier_ignore/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_prettier_ignore/__snapshots__/jsfmt.spec.js.snap
@@ -13,7 +13,7 @@ aaaaa:
 ---
 aaaaa:
            bbbbb
-...
+---
 aaaaa: bbbbb
 
 `;
diff --git a/tests/yaml_spec/__snapshots__/jsfmt.spec.js.snap b/tests/yaml_spec/__snapshots__/jsfmt.spec.js.snap
index 816e9061ae07..6ada0df4e82f 100644
--- a/tests/yaml_spec/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/yaml_spec/__snapshots__/jsfmt.spec.js.snap
@@ -3445,13 +3445,11 @@ exports[`spec-example-6-21-local-tag-prefix.yml - yaml-verify 1`] = `
 !m!light green
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 %TAG !m! !my-
----
-# Bulb here
+--- # Bulb here
 !m!light fluorescent
 ...
 %TAG !m! !my-
----
-# Color here
+--- # Color here
 !m!light green
 
 `;
@@ -3466,13 +3464,11 @@ exports[`spec-example-6-21-local-tag-prefix.yml - yaml-verify 2`] = `
 !m!light green
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 %TAG !m! !my-
----
-# Bulb here
+--- # Bulb here
 !m!light fluorescent
 ...
 %TAG !m! !my-
----
-# Color here
+--- # Color here
 !m!light green
 
 `;
@@ -4334,7 +4330,6 @@ keep: |+
 
 # Trail
 # comments.
-
 `;
 
 exports[`spec-example-8-5-chomping-trailing-lines.yml - yaml-verify 2`] = `
@@ -4377,7 +4372,6 @@ keep: |+
 
 # Trail
 # comments.
-
 `;
 
 exports[`spec-example-8-6-empty-scalar-chomping.yml - yaml-verify 1`] = `
diff --git a/yarn.lock b/yarn.lock
index 34052b7aa273..e6c4b67dc2d3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5665,11 +5665,11 @@ tryit@^1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/tryit/-/tryit-1.0.3.tgz#393be730a9446fd1ead6da59a014308f36c289cb"
 
-tslib@^1.8.0, tslib@^1.9.1:
+tslib@^1.8.0:
   version "1.9.1"
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.9.1.tgz#a5d1f0532a49221c87755cfcc89ca37197242ba7"
 
-tslib@^1.9.3:
+tslib@^1.9.1, tslib@^1.9.3:
   version "1.9.3"
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.9.3.tgz#d7e4dd79245d85428c4d7e4822a79917954ca286"
 
@@ -6119,16 +6119,16 @@ yallist@^3.0.0, yallist@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/yallist/-/yallist-3.0.2.tgz#8452b4bb7e83c7c188d8041c1a837c773d6d8bb9"
 
-yaml-unist-parser@ikatyang/yaml-unist-parser#cd4f73325b3fc02a6d17842d0d9cee0dfc729c9b:
-  version "1.0.0-rc.3"
-  resolved "https://codeload.github.com/ikatyang/yaml-unist-parser/tar.gz/cd4f73325b3fc02a6d17842d0d9cee0dfc729c9b"
+yaml-unist-parser@1.0.0-rc.4:
+  version "1.0.0-rc.4"
+  resolved "https://registry.yarnpkg.com/yaml-unist-parser/-/yaml-unist-parser-1.0.0-rc.4.tgz#d8fb9c673d59a4f7d532840b120abd6400237014"
   dependencies:
     lines-and-columns "^1.1.6"
     tslib "^1.9.1"
 
-yaml@ikatyang/yaml#a765c1ee16d6b8a5e715564645f2b85f7e04828b:
-  version "1.0.0-rc.7"
-  resolved "https://codeload.github.com/ikatyang/yaml/tar.gz/a765c1ee16d6b8a5e715564645f2b85f7e04828b"
+yaml@1.0.0-rc.8:
+  version "1.0.0-rc.8"
+  resolved "https://registry.yarnpkg.com/yaml/-/yaml-1.0.0-rc.8.tgz#e5604c52b7b07b16e469bcf875ab0dfe08c50d42"
 
 yargs-parser@^7.0.0:
   version "7.0.0"