Make curried arrow function and normal arrow function consistent (#14633)

Co-authored-by: fisker Cheung <lionkay@gmail.com>

changelog_unreleased/javascript/14633.md

@@ -0,0 +1,16 @@
+#### Improve consistency between curried and non-curried arrow function (#14633 by @seiyab, @fisker)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+Y(() => a ? b : c);
+Y(() => () => a ? b : c);
+
+// Prettier stable
+Y(() => (a ? b : c));
+Y(() => () => a ? b : c);
+
+// Prettier main
+Y(() => (a ? b : c));
+Y(() => () => (a ? b : c));
+```

src/language-js/print/arrow-function.js

@@ -0,0 +1,329 @@
+import {
+  printDanglingComments,
+  printCommentsSeparately,
+} from "../../main/comments/print.js";
+import getNextNonSpaceNonCommentCharacterIndex from "../../utils/get-next-non-space-non-comment-character-index.js";
+import {
+  line,
+  softline,
+  group,
+  indent,
+  ifBreak,
+  join,
+  indentIfBreak,
+} from "../../document/builders.js";
+import { removeLines, willBreak } from "../../document/utils.js";
+import { ArgExpansionBailout } from "../../common/errors.js";
+import {
+  getFunctionParameters,
+  hasLeadingOwnLineComment,
+  isJsxElement,
+  isTemplateOnItsOwnLine,
+  shouldPrintComma,
+  startsWithNoLookaheadToken,
+  isBinaryish,
+  hasComment,
+  isCallLikeExpression,
+  isArrayOrTupleExpression,
+  isObjectOrRecordExpression,
+} from "../utils/index.js";
+import { locEnd } from "../loc.js";
+import { printFunctionParameters } from "./function-parameters.js";
+import { printReturnType, shouldPrintParamsWithoutParens } from "./function.js";
+
+/**
+ * @typedef {import("../../common/ast-path.js").default} AstPath
+ * @typedef {import("../../document/builders.js").Doc} Doc
+ */
+
+// In order to avoid confusion between
+// a => a ? a : a
+// a <= a ? a : a
+const shouldAddParensIfNotBreakCache = new WeakMap();
+function shouldAddParensIfNotBreak(node) {
+  if (!shouldAddParensIfNotBreakCache.has(node)) {
+    shouldAddParensIfNotBreakCache.set(
+      node,
+      node.type === "ConditionalExpression" &&
+        !startsWithNoLookaheadToken(
+          node,
+          (node) => node.type === "ObjectExpression"
+        )
+    );
+  }
+  return shouldAddParensIfNotBreakCache.get(node);
+}
+
+// We handle sequence expressions as the body of arrows specially,
+// so that the required parentheses end up on their own lines.
+const shouldAlwaysAddParens = (node) => node.type === "SequenceExpression";
+
+function printArrowFunction(path, options, print, args = {}) {
+  /** @type {Doc[]} */
+  const signatureDocs = [];
+  /** @type {Doc} */
+  let bodyDoc;
+  /** @type {Doc[]} */
+  const bodyComments = [];
+  let shouldBreakChain = false;
+  const shouldPrintAsChain =
+    !args.expandLastArg && path.node.body.type === "ArrowFunctionExpression";
+  let functionBody;
+
+  (function rec() {
+    const { node } = path;
+    const signatureDoc = printArrowFunctionSignature(
+      path,
+      options,
+      print,
+      args
+    );
+    if (signatureDocs.length === 0) {
+      signatureDocs.push(signatureDoc);
+    } else {
+      const { leading, trailing } = printCommentsSeparately(path, options);
+      signatureDocs.push([leading, signatureDoc]);
+      bodyComments.unshift(trailing);
+    }
+
+    if (shouldPrintAsChain) {
+      shouldBreakChain ||=
+        // Always break the chain if:
+        (node.returnType && getFunctionParameters(node).length > 0) ||
+        node.typeParameters ||
+        getFunctionParameters(node).some(
+          (param) => param.type !== "Identifier"
+        );
+    }
+
+    if (!shouldPrintAsChain || node.body.type !== "ArrowFunctionExpression") {
+      bodyDoc = print("body", args);
+      functionBody = node.body;
+    } else {
+      path.call(rec, "body");
+    }
+  })();
+
+  // We want to always keep these types of nodes on the same line
+  // as the arrow.
+  const shouldPutBodyOnSameLine =
+    !hasLeadingOwnLineComment(options.originalText, functionBody) &&
+    (shouldAlwaysAddParens(functionBody) ||
+      mayBreakAfterShortPrefix(functionBody, bodyDoc, options) ||
+      (!shouldBreakChain && shouldAddParensIfNotBreak(functionBody)));
+
+  const isCallee = path.key === "callee" && isCallLikeExpression(path.parent);
+  const chainGroupId = Symbol("arrow-chain");
+
+  const signaturesDoc = printArrowFunctionSignatures(path, args, {
+    signatureDocs,
+    shouldBreak: shouldBreakChain,
+  });
+  let shouldBreakSignatures;
+  let shouldIndentSignatures = false;
+  if (
+    shouldPrintAsChain &&
+    (isCallee ||
+      // isAssignmentRhs
+      args.assignmentLayout)
+  ) {
+    shouldIndentSignatures = true;
+    shouldBreakSignatures =
+      args.assignmentLayout === "chain-tail-arrow-chain" ||
+      (isCallee && !shouldPutBodyOnSameLine);
+  }
+
+  bodyDoc = printArrowFunctionBody(path, options, args, {
+    bodyDoc,
+    bodyComments,
+    functionBody,
+    shouldPutBodyOnSameLine,
+  });
+
+  return group([
+    group(
+      shouldIndentSignatures
+        ? indent([softline, signaturesDoc])
+        : signaturesDoc,
+      { shouldBreak: shouldBreakSignatures, id: chainGroupId }
+    ),
+    " =>",
+    shouldPrintAsChain
+      ? indentIfBreak(bodyDoc, { groupId: chainGroupId })
+      : group(bodyDoc),
+    shouldPrintAsChain && isCallee
+      ? ifBreak(softline, "", { groupId: chainGroupId })
+      : "",
+  ]);
+}
+
+function printArrowFunctionSignature(path, options, print, args) {
+  const { node } = path;
+  const parts = [];
+
+  if (node.async) {
+    parts.push("async ");
+  }
+
+  if (shouldPrintParamsWithoutParens(path, options)) {
+    parts.push(print(["params", 0]));
+  } else {
+    const expandArg = args.expandLastArg || args.expandFirstArg;
+    let returnTypeDoc = printReturnType(path, print);
+    if (expandArg) {
+      if (willBreak(returnTypeDoc)) {
+        throw new ArgExpansionBailout();
+      }
+      returnTypeDoc = group(removeLines(returnTypeDoc));
+    }
+    parts.push(
+      group([
+        printFunctionParameters(
+          path,
+          print,
+          options,
+          expandArg,
+          /* printTypeParams */ true
+        ),
+        returnTypeDoc,
+      ])
+    );
+  }
+
+  const dangling = printDanglingComments(path, options, {
+    filter(comment) {
+      const nextCharacter = getNextNonSpaceNonCommentCharacterIndex(
+        options.originalText,
+        locEnd(comment)
+      );
+      return (
+        nextCharacter !== false &&
+        options.originalText.slice(nextCharacter, nextCharacter + 2) === "=>"
+      );
+    },
+  });
+  if (dangling) {
+    parts.push(" ", dangling);
+  }
+  return parts;
+}
+
+/**
+ *
+ * @param {*} functionBody
+ * @param {*} bodyDoc
+ * @param {*} options
+ * @returns {boolean}
+ */
+function mayBreakAfterShortPrefix(functionBody, bodyDoc, options) {
+  return (
+    isArrayOrTupleExpression(functionBody) ||
+    isObjectOrRecordExpression(functionBody) ||
+    functionBody.type === "ArrowFunctionExpression" ||
+    functionBody.type === "DoExpression" ||
+    functionBody.type === "BlockStatement" ||
+    isJsxElement(functionBody) ||
+    (bodyDoc.label?.hug !== false &&
+      (bodyDoc.label?.embed ||
+        isTemplateOnItsOwnLine(functionBody, options.originalText)))
+  );
+}
+
+/**
+ * @param {AstPath} path
+ * @param {*} args
+ * @param {Object} arrowFunctionSignaturesPrintOptions
+ * @param {Doc[]} arrowFunctionSignaturesPrintOptions.signatureDocs
+ * @param {boolean} arrowFunctionSignaturesPrintOptions.shouldBreak
+ * @returns {Doc}
+ */
+function printArrowFunctionSignatures(
+  path,
+  args,
+  { signatureDocs, shouldBreak }
+) {
+  if (signatureDocs.length === 1) {
+    return signatureDocs[0];
+  }
+
+  const { parent, key } = path;
+  if (
+    (key !== "callee" && isCallLikeExpression(parent)) ||
+    isBinaryish(parent)
+  ) {
+    return group(
+      [
+        signatureDocs[0],
+        " =>",
+        indent([line, join([" =>", line], signatureDocs.slice(1))]),
+      ],
+      { shouldBreak }
+    );
+  }
+
+  if (
+    (key === "callee" && isCallLikeExpression(parent)) ||
+    // isAssignmentRhs
+    args.assignmentLayout
+  ) {
+    return group(join([" =>", line], signatureDocs), { shouldBreak });
+  }
+
+  return group(indent(join([" =>", line], signatureDocs)), { shouldBreak });
+}
+
+/**
+ * @param {AstPath} path
+ * @param {*} options
+ * @param {*} args
+ * @param {Object} arrowFunctionBodyPrintOptions
+ * @param {Doc} arrowFunctionBodyPrintOptions.bodyDoc
+ * @param {Doc[]} arrowFunctionBodyPrintOptions.bodyComments
+ * @param {*} arrowFunctionBodyPrintOptions.functionBody
+ * @param {boolean} arrowFunctionBodyPrintOptions.shouldPutBodyOnSameLine
+ */
+function printArrowFunctionBody(
+  path,
+  options,
+  args,
+  { bodyDoc, bodyComments, functionBody, shouldPutBodyOnSameLine }
+) {
+  const { node, parent } = path;
+
+  const trailingComma =
+    args.expandLastArg && shouldPrintComma(options, "all") ? ifBreak(",") : "";
+
+  // if the arrow function is expanded as last argument, we are adding a
+  // level of indentation and need to add a softline to align the closing )
+  // with the opening (, or if it's inside a JSXExpression (e.g. an attribute)
+  // we should align the expression's closing } with the line with the opening {.
+  const trailingSpace =
+    (args.expandLastArg || parent.type === "JSXExpressionContainer") &&
+    !hasComment(node)
+      ? softline
+      : "";
+
+  if (shouldPutBodyOnSameLine && shouldAddParensIfNotBreak(functionBody)) {
+    return [
+      " ",
+      group([
+        ifBreak("", "("),
+        indent([softline, bodyDoc]),
+        ifBreak("", ")"),
+        trailingComma,
+        trailingSpace,
+      ]),
+      bodyComments,
+    ];
+  }
+
+  if (shouldAlwaysAddParens(functionBody)) {
+    bodyDoc = group(["(", indent([softline, bodyDoc]), softline, ")"]);
+  }
+
+  return shouldPutBodyOnSameLine
+    ? [" ", bodyDoc, bodyComments]
+    : [indent([line, bodyDoc, bodyComments]), trailingComma, trailingSpace];
+}
+
+export { printArrowFunction };

src/language-js/print/function.js

@@ -1,43 +1,23 @@
-/** @typedef {import("../../document/builders.js").Doc} Doc */
-
 import assert from "node:assert";
+import { printDanglingComments } from "../../main/comments/print.js";
 import {
-  printDanglingComments,
-  printCommentsSeparately,
-} from "../../main/comments/print.js";
-import getNextNonSpaceNonCommentCharacterIndex from "../../utils/get-next-non-space-non-comment-character-index.js";
-import {
-  line,
   softline,
   group,
   indent,
-  dedent,
   ifBreak,
   hardline,
-  join,
-  indentIfBreak,
 } from "../../document/builders.js";
-import { removeLines, willBreak } from "../../document/utils.js";
-import { ArgExpansionBailout } from "../../common/errors.js";
 import {
   getFunctionParameters,
   hasLeadingOwnLineComment,
-  isJsxElement,
-  isTemplateOnItsOwnLine,
-  shouldPrintComma,
-  startsWithNoLookaheadToken,
   isBinaryish,
   hasComment,
   CommentCheckFlags,
-  isCallLikeExpression,
   isCallExpression,
   getCallArguments,
   hasNakedLeftSide,
   getLeftSide,
-  isArrayOrTupleExpression,
-  isObjectOrRecordExpression,
 } from "../utils/index.js";
-import { locEnd } from "../loc.js";
 import {
   printFunctionParameters,
   shouldGroupFunctionParameters,
@@ -47,6 +27,11 @@ import { printPropertyKey } from "./property.js";
 import { printFunctionTypeParameters, printDeclareToken } from "./misc.js";
 import { printTypeAnnotationProperty } from "./type-annotation.js";
 
+/**
+ * @typedef {import("../../common/ast-path.js").default} AstPath
+ * @typedef {import("../../document/builders.js").Doc} Doc
+ */
+
 const isMethod = (node) =>
   node.type === "ObjectMethod" ||
   node.type === "ClassMethod" ||
@@ -198,214 +183,6 @@ function printMethodValue(path, options, print) {
   return parts;
 }
 
-function printArrowFunctionSignature(path, options, print, args) {
-  const { node } = path;
-  const parts = [];
-
-  if (node.async) {
-    parts.push("async ");
-  }
-
-  if (shouldPrintParamsWithoutParens(path, options)) {
-    parts.push(print(["params", 0]));
-  } else {
-    const expandArg = args?.expandLastArg || args?.expandFirstArg;
-    let returnTypeDoc = printReturnType(path, print);
-    if (expandArg) {
-      if (willBreak(returnTypeDoc)) {
-        throw new ArgExpansionBailout();
-      }
-      returnTypeDoc = group(removeLines(returnTypeDoc));
-    }
-    parts.push(
-      group([
-        printFunctionParameters(
-          path,
-          print,
-          options,
-          expandArg,
-          /* printTypeParams */ true
-        ),
-        returnTypeDoc,
-      ])
-    );
-  }
-
-  const dangling = printDanglingComments(path, options, {
-    filter(comment) {
-      const nextCharacter = getNextNonSpaceNonCommentCharacterIndex(
-        options.originalText,
-        locEnd(comment)
-      );
-      return (
-        nextCharacter !== false &&
-        options.originalText.slice(nextCharacter, nextCharacter + 2) === "=>"
-      );
-    },
-  });
-  if (dangling) {
-    parts.push(" ", dangling);
-  }
-  return parts;
-}
-
-function printArrowChain(
-  path,
-  args,
-  signatures,
-  shouldBreak,
-  bodyDoc,
-  tailNode
-) {
-  const { parent, key } = path;
-  const isCallee = isCallLikeExpression(parent) && key === "callee";
-  const isAssignmentRhs = Boolean(args?.assignmentLayout);
-  const shouldPutBodyOnSeparateLine =
-    tailNode.body.type !== "BlockStatement" &&
-    !isObjectOrRecordExpression(tailNode.body) &&
-    tailNode.body.type !== "SequenceExpression";
-  const shouldBreakBeforeChain =
-    (isCallee && shouldPutBodyOnSeparateLine) ||
-    args?.assignmentLayout === "chain-tail-arrow-chain";
-
-  const groupId = Symbol("arrow-chain");
-
-  if ((isCallLikeExpression(parent) && !isCallee) || isBinaryish(parent)) {
-    signatures = [dedent(signatures[0]), ...signatures.slice(1)];
-  }
-
-  // We handle sequence expressions as the body of arrows specially,
-  // so that the required parentheses end up on their own lines.
-  if (tailNode.body.type === "SequenceExpression") {
-    bodyDoc = group(["(", indent([softline, bodyDoc]), softline, ")"]);
-  }
-
-  return group([
-    group(
-      indent([
-        isCallee || isAssignmentRhs ? softline : "",
-        group(join([" =>", line], signatures), { shouldBreak }),
-      ]),
-      { id: groupId, shouldBreak: shouldBreakBeforeChain }
-    ),
-    " =>",
-    indentIfBreak(
-      shouldPutBodyOnSeparateLine ? indent([line, bodyDoc]) : [" ", bodyDoc],
-      { groupId }
-    ),
-    isCallee ? ifBreak(softline, "", { groupId }) : "",
-  ]);
-}
-
-function printArrowFunction(path, options, print, args) {
-  let { node } = path;
-  /** @type {Doc[]} */
-  const signatures = [];
-  const body = [];
-  let chainShouldBreak = false;
-
-  (function rec() {
-    const doc = printArrowFunctionSignature(path, options, print, args);
-    if (signatures.length === 0) {
-      signatures.push(doc);
-    } else {
-      const { leading, trailing } = printCommentsSeparately(path, options);
-      signatures.push([leading, doc]);
-      body.unshift(trailing);
-    }
-
-    chainShouldBreak =
-      chainShouldBreak ||
-      // Always break the chain if:
-      (node.returnType && getFunctionParameters(node).length > 0) ||
-      node.typeParameters ||
-      getFunctionParameters(node).some((param) => param.type !== "Identifier");
-
-    if (node.body.type !== "ArrowFunctionExpression" || args?.expandLastArg) {
-      body.unshift(print("body", args));
-    } else {
-      node = node.body;
-      path.call(rec, "body");
-    }
-  })();
-
-  if (signatures.length > 1) {
-    return printArrowChain(
-      path,
-      args,
-      signatures,
-      chainShouldBreak,
-      body,
-      node
-    );
-  }
-
-  const parts = signatures;
-  parts.push(" =>");
-
-  // We want to always keep these types of nodes on the same line
-  // as the arrow.
-  if (
-    !hasLeadingOwnLineComment(options.originalText, node.body) &&
-    (isArrayOrTupleExpression(node.body) ||
-      isObjectOrRecordExpression(node.body) ||
-      node.body.type === "BlockStatement" ||
-      isJsxElement(node.body) ||
-      (body[0].label?.hug !== false &&
-        (body[0].label?.embed ||
-          isTemplateOnItsOwnLine(node.body, options.originalText))) ||
-      node.body.type === "ArrowFunctionExpression" ||
-      node.body.type === "DoExpression")
-  ) {
-    return group([...parts, " ", body]);
-  }
-
-  // We handle sequence expressions as the body of arrows specially,
-  // so that the required parentheses end up on their own lines.
-  if (node.body.type === "SequenceExpression") {
-    return group([
-      ...parts,
-      group([" (", indent([softline, body]), softline, ")"]),
-    ]);
-  }
-
-  // if the arrow function is expanded as last argument, we are adding a
-  // level of indentation and need to add a softline to align the closing )
-  // with the opening (, or if it's inside a JSXExpression (e.g. an attribute)
-  // we should align the expression's closing } with the line with the opening {.
-  const shouldAddSoftLine =
-    (args?.expandLastArg || path.parent.type === "JSXExpressionContainer") &&
-    !hasComment(node);
-
-  const printTrailingComma =
-    args?.expandLastArg && shouldPrintComma(options, "all");
-
-  // In order to avoid confusion between
-  // a => a ? a : a
-  // a <= a ? a : a
-  const shouldAddParens =
-    node.body.type === "ConditionalExpression" &&
-    !startsWithNoLookaheadToken(
-      node.body,
-      (node) => node.type === "ObjectExpression"
-    );
-
-  return group([
-    ...parts,
-    group([
-      indent([
-        line,
-        shouldAddParens ? ifBreak("", "(") : "",
-        body,
-        shouldAddParens ? ifBreak("", ")") : "",
-      ]),
-      shouldAddSoftLine
-        ? [ifBreak(printTrailingComma ? "," : ""), softline]
-        : "",
-    ]),
-  ]);
-}
-
 function canPrintParamsWithoutParens(node) {
   const parameters = getFunctionParameters(node);
   return (
@@ -530,10 +307,10 @@ function returnArgumentHasLeadingComment(options, argument) {
 
 export {
   printFunction,
-  printArrowFunction,
   printMethod,
   printReturnStatement,
   printThrowStatement,
   printMethodValue,
+  printReturnType,
   shouldPrintParamsWithoutParens,
 };

src/language-js/printer-estree.js

@@ -65,11 +65,11 @@ import {
 import { printProperty } from "./print/property.js";
 import {
   printFunction,
-  printArrowFunction,
   printMethod,
   printReturnStatement,
   printThrowStatement,
 } from "./print/function.js";
+import { printArrowFunction } from "./print/arrow-function.js";
 import { printCallExpression } from "./print/call-expression.js";
 import {
   printVariableDeclarator,

tests/format/js/arrows/__snapshots__/jsfmt.spec.js.snap

@@ -2334,6 +2334,27 @@ export const bem = block =>
   data={data}
 />
 
+func(() => // comment
+a);
+func(() => () => // comment
+a);
+func(() => () => () => // comment
+a);
+
+func(() => // comment
+a ? b : c);
+func(() => () => // comment
+a ? b : c);
+func(() => () => () => // comment
+a ? b : c);
+
+func(() => // comment
+(a , b , c))
+func(() => () => // comment
+(a , b , c))
+func(() => () => () => // comment
+(a , b , c))
+
 =====================================output=====================================
 /**
  * Curried function that ends with a BEM CSS Selector
@@ -2367,6 +2388,59 @@ export const bem =
   data={data}
 />;
 
+func(
+  () =>
+    // comment
+    a,
+);
+func(
+  () => () =>
+    // comment
+    a,
+);
+func(
+  () => () => () =>
+    // comment
+    a,
+);
+
+func(() =>
+  // comment
+  a ? b : c,
+);
+func(
+  () => () =>
+    // comment
+    a ? b : c,
+);
+func(
+  () => () => () =>
+    // comment
+    a ? b : c,
+);
+
+func(
+  () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+func(
+  () => () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+func(
+  () => () => () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+
 ================================================================================
 `;
 
@@ -2408,6 +2482,27 @@ export const bem = block =>
   data={data}
 />
 
+func(() => // comment
+a);
+func(() => () => // comment
+a);
+func(() => () => () => // comment
+a);
+
+func(() => // comment
+a ? b : c);
+func(() => () => // comment
+a ? b : c);
+func(() => () => () => // comment
+a ? b : c);
+
+func(() => // comment
+(a , b , c))
+func(() => () => // comment
+(a , b , c))
+func(() => () => () => // comment
+(a , b , c))
+
 =====================================output=====================================
 /**
  * Curried function that ends with a BEM CSS Selector
@@ -2441,6 +2536,59 @@ export const bem =
   data={data}
 />;
 
+func(
+  () =>
+    // comment
+    a,
+);
+func(
+  () => () =>
+    // comment
+    a,
+);
+func(
+  () => () => () =>
+    // comment
+    a,
+);
+
+func(() =>
+  // comment
+  a ? b : c,
+);
+func(
+  () => () =>
+    // comment
+    a ? b : c,
+);
+func(
+  () => () => () =>
+    // comment
+    a ? b : c,
+);
+
+func(
+  () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+func(
+  () => () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+func(
+  () => () => () =>
+    (
+      // comment
+      a, b, c
+    ),
+);
+
 ================================================================================
 `;
 
@@ -3666,6 +3814,370 @@ function f(
 ================================================================================
 `;
 
+exports[`currying-4.js - {"arrowParens":"always"} format 1`] = `
+====================================options=====================================
+arrowParens: "always"
+parsers: ["babel", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+Y(() => a ? b : c);
+
+Y(() => () => a ? b : c);
+
+Y(() => () => () => a ? b : c);
+
+Y(() => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+const x1 = (() => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x2 = (() => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x3 = (() => () => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+f((a) => (1, 2, 3) /* a */);
+f((a) => (
+  (b) => (1, 2, 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1, 2, 3) /* c */
+  ) /* b */
+) /* a */);
+
+f((a) => (1 ? 2 : 3) /* a */);
+f((a) => (
+  (b) => (1 ? 2 : 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1 ? 2 : 3) /* c */
+  ) /* b */
+) /* a */);
+
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => test,
+);
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => (test ? 1 : 2),
+);
+
+=====================================output=====================================
+Y(() => (a ? b : c));
+
+Y(() => () => (a ? b : c));
+
+Y(() => () => () => (a ? b : c));
+
+Y(() =>
+  longlonglonglonglonglonglonglonglonglongCondition
+    ? "Prettier is an opinionated code formatter."
+    : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+Y(
+  () => () =>
+    longlonglonglonglonglonglonglonglonglongCondition
+      ? "Prettier is an opinionated code formatter."
+      : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+Y(
+  () => () => () =>
+    longlonglonglonglonglonglonglonglonglongCondition
+      ? "Prettier is an opinionated code formatter."
+      : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+const x1 = () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+const x2 = () => () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+const x3 = () => () => () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+f((a) => (1, 2, 3) /* a */);
+f((a) => (b) => (1, 2, 3) /* b */ /* a */);
+f((a) => (b) => (c) => (1, 2, 3) /* c */ /* b */ /* a */);
+
+f((a) => (1 ? 2 : 3) /* a */);
+f((a) => (b) => (1 ? 2 : 3) /* b */ /* a */);
+f((a) => (b) => (c) => (1 ? 2 : 3) /* c */ /* b */ /* a */);
+
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+      test,
+);
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+      test ? 1 : 2,
+);
+
+================================================================================
+`;
+
+exports[`currying-4.js - {"arrowParens":"avoid"} format 1`] = `
+====================================options=====================================
+arrowParens: "avoid"
+parsers: ["babel", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+Y(() => a ? b : c);
+
+Y(() => () => a ? b : c);
+
+Y(() => () => () => a ? b : c);
+
+Y(() => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+const x1 = (() => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x2 = (() => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x3 = (() => () => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+f((a) => (1, 2, 3) /* a */);
+f((a) => (
+  (b) => (1, 2, 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1, 2, 3) /* c */
+  ) /* b */
+) /* a */);
+
+f((a) => (1 ? 2 : 3) /* a */);
+f((a) => (
+  (b) => (1 ? 2 : 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1 ? 2 : 3) /* c */
+  ) /* b */
+) /* a */);
+
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => test,
+);
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => (test ? 1 : 2),
+);
+
+=====================================output=====================================
+Y(() => (a ? b : c));
+
+Y(() => () => (a ? b : c));
+
+Y(() => () => () => (a ? b : c));
+
+Y(() =>
+  longlonglonglonglonglonglonglonglonglongCondition
+    ? "Prettier is an opinionated code formatter."
+    : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+Y(
+  () => () =>
+    longlonglonglonglonglonglonglonglonglongCondition
+      ? "Prettier is an opinionated code formatter."
+      : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+Y(
+  () => () => () =>
+    longlonglonglonglonglonglonglonglonglongCondition
+      ? "Prettier is an opinionated code formatter."
+      : "Prettier takes your code and reprints it from scratch by taking the line length into account.",
+);
+
+const x1 = () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+const x2 = () => () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+const x3 = () => () => () => [
+  "The",
+  "green",
+  "dragon",
+  "liked",
+  "to",
+  "knit",
+  "sweaters",
+  "for",
+  "the",
+  "fluffy",
+  "clouds",
+  "in",
+  "the",
+  "sky.",
+];
+
+f(a => (1, 2, 3) /* a */);
+f(a => b => (1, 2, 3) /* b */ /* a */);
+f(a => b => c => (1, 2, 3) /* c */ /* b */ /* a */);
+
+f(a => (1 ? 2 : 3) /* a */);
+f(a => b => (1 ? 2 : 3) /* b */ /* a */);
+f(a => b => c => (1 ? 2 : 3) /* c */ /* b */ /* a */);
+
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+      test,
+);
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+      test ? 1 : 2,
+);
+
+================================================================================
+`;
+
 exports[`issue-1389-curry.js - {"arrowParens":"always"} format 1`] = `
 ====================================options=====================================
 arrowParens: "always"
@@ -3928,6 +4440,9 @@ foo(a => b, d)
 foo(a => (0, 1));
 foo(a => b => (0, 1));
 
+() => ({} ? 1 : 2);
+() => () => ({} ? 1 : 2);
+
 =====================================output=====================================
 promise.then(
   (result) => result,
@@ -3956,6 +4471,9 @@ foo((a) => b, d);
 foo((a) => (0, 1));
 foo((a) => (b) => (0, 1));
 
+() => ({}) ? 1 : 2;
+() => () => ({}) ? 1 : 2;
+
 ================================================================================
 `;
 
@@ -3985,6 +4503,9 @@ foo(a => b, d)
 foo(a => (0, 1));
 foo(a => b => (0, 1));
 
+() => ({} ? 1 : 2);
+() => () => ({} ? 1 : 2);
+
 =====================================output=====================================
 promise.then(
   result => result,
@@ -4013,6 +4534,9 @@ foo(a => b, d);
 foo(a => (0, 1));
 foo(a => b => (0, 1));
 
+() => ({}) ? 1 : 2;
+() => () => ({}) ? 1 : 2;
+
 ================================================================================
 `;
 

tests/format/js/arrows/comment.js

@@ -28,3 +28,24 @@ export const bem = block =>
   ) => <span>{info.item.widget.missingProp}</span>}
   data={data}
 />
+
+func(() => // comment
+a);
+func(() => () => // comment
+a);
+func(() => () => () => // comment
+a);
+
+func(() => // comment
+a ? b : c);
+func(() => () => // comment
+a ? b : c);
+func(() => () => () => // comment
+a ? b : c);
+
+func(() => // comment
+(a , b , c))
+func(() => () => // comment
+(a , b , c))
+func(() => () => () => // comment
+(a , b , c))

tests/format/js/arrows/currying-4.js

@@ -0,0 +1,60 @@
+Y(() => a ? b : c);
+
+Y(() => () => a ? b : c);
+
+Y(() => () => () => a ? b : c);
+
+Y(() => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+Y(() => () => () => longlonglonglonglonglonglonglonglonglongCondition ? 'Prettier is an opinionated code formatter.' : 'Prettier takes your code and reprints it from scratch by taking the line length into account.')
+
+const x1 = (() => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x2 = (() => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+const x3 = (() => () => () => ['The', 'green', 'dragon', 'liked', 'to', 'knit', 'sweaters', 'for', 'the', 'fluffy', 'clouds', 'in', 'the', 'sky.'])
+
+f((a) => (1, 2, 3) /* a */);
+f((a) => (
+  (b) => (1, 2, 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1, 2, 3) /* c */
+  ) /* b */
+) /* a */);
+
+f((a) => (1 ? 2 : 3) /* a */);
+f((a) => (
+  (b) => (1 ? 2 : 3) /* b */
+) /* a */);
+f((a) => (
+  (b) => (
+   (c) => (1 ? 2 : 3) /* c */
+  ) /* b */
+) /* a */);
+
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => test,
+);
+a(
+  "",
+  "",
+  ({}) =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () =>
+    () => (test ? 1 : 2),
+);

tests/format/js/arrows/parens.js

@@ -16,3 +16,6 @@ foo(a => b, d)
 
 foo(a => (0, 1));
 foo(a => b => (0, 1));
+
+() => ({} ? 1 : 2);
+() => () => ({} ? 1 : 2);

tests/format/js/do/__snapshots__/jsfmt.spec.js.snap

@@ -213,6 +213,20 @@ function foo() {
   }
 };
 
+() => (    ) => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};
+
+a =>b=>     c => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};
+
 =====================================output=====================================
 const envSpecific = {
   domain: do {
@@ -272,5 +286,19 @@ function foo() {
   }
 };
 
+() => () => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};
+
+(a) => (b) => (c) => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};
+
 ================================================================================
 `;

tests/format/js/do/do.js

@@ -52,3 +52,17 @@ function foo() {
     obj[key];
   }
 };
+
+() => (    ) => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};
+
+a =>b=>     c => do {
+  var obj = { foo: "bar", bar: "foo" };
+  for (var key in obj) {
+    obj[key];
+  }
+};

tests/format/jsx/jsx/__snapshots__/jsfmt.spec.js.snap

@@ -312,6 +312,374 @@ const TodoList = ({ todos }) => (
 ================================================================================
 `;
 
+exports[`arrow.js - {"singleQuote":false,"jsxSingleQuote":false} format 1`] = `
+====================================options=====================================
+jsxSingleQuote: false
+parsers: ["flow", "babel", "typescript"]
+printWidth: 80
+singleQuote: false
+                                                                                | printWidth
+=====================================input======================================
+() => <Component><Children/></Component>;
+() => () => <Component><Children/></Component>;
+() => () => () => <Component><Children/></Component>;
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+
+<Prettier>
+  {We => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => currying => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+
+=====================================output=====================================
+() => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+
+<Prettier>
+  {(We) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) => (currying) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+
+================================================================================
+`;
+
+exports[`arrow.js - {"singleQuote":false,"jsxSingleQuote":true} format 1`] = `
+====================================options=====================================
+jsxSingleQuote: true
+parsers: ["flow", "babel", "typescript"]
+printWidth: 80
+singleQuote: false
+                                                                                | printWidth
+=====================================input======================================
+() => <Component><Children/></Component>;
+() => () => <Component><Children/></Component>;
+() => () => () => <Component><Children/></Component>;
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+
+<Prettier>
+  {We => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => currying => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+
+=====================================output=====================================
+() => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+
+<Prettier>
+  {(We) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) => (currying) =>
+    "The purple monkey danced with a tambourine made of cheese." +
+    "The robot chef cooked a cake that tasted like rainbows." +
+    "The talking pineapple sang a lullaby to the sleepy giraffe."
+  }
+</Prettier>;
+
+================================================================================
+`;
+
+exports[`arrow.js - {"singleQuote":true,"jsxSingleQuote":false} format 1`] = `
+====================================options=====================================
+jsxSingleQuote: false
+parsers: ["flow", "babel", "typescript"]
+printWidth: 80
+singleQuote: true
+                                                                                | printWidth
+=====================================input======================================
+() => <Component><Children/></Component>;
+() => () => <Component><Children/></Component>;
+() => () => () => <Component><Children/></Component>;
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+
+<Prettier>
+  {We => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => currying => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+
+=====================================output=====================================
+() => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+
+<Prettier>
+  {(We) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) => (currying) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+
+================================================================================
+`;
+
+exports[`arrow.js - {"singleQuote":true,"jsxSingleQuote":true} format 1`] = `
+====================================options=====================================
+jsxSingleQuote: true
+parsers: ["flow", "babel", "typescript"]
+printWidth: 80
+singleQuote: true
+                                                                                | printWidth
+=====================================input======================================
+() => <Component><Children/></Component>;
+() => () => <Component><Children/></Component>;
+() => () => () => <Component><Children/></Component>;
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+
+<Prettier>
+  {We => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => currying => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+
+=====================================output=====================================
+() => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+() => () => () => (
+  <Component>
+    <Children />
+  </Component>
+);
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+() => () => () => (
+  <div>
+    Long long long long long, very very long text. And more text. Another text.
+  </div>
+);
+
+<Prettier>
+  {(We) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+<Prettier>
+  {(We) => (love) => (currying) =>
+    'The purple monkey danced with a tambourine made of cheese.' +
+    'The robot chef cooked a cake that tasted like rainbows.' +
+    'The talking pineapple sang a lullaby to the sleepy giraffe.'
+  }
+</Prettier>;
+
+================================================================================
+`;
+
 exports[`attr-comments.js - {"singleQuote":false,"jsxSingleQuote":false} format 1`] = `
 ====================================options=====================================
 jsxSingleQuote: false

tests/format/jsx/jsx/arrow.js

@@ -0,0 +1,21 @@
+() => <Component><Children/></Component>;
+() => () => <Component><Children/></Component>;
+() => () => () => <Component><Children/></Component>;
+
+() => <div>Some text here</div>;
+() => () => <div>Some text here</div>;
+() => () => () => <div>Some text here</div>;
+
+() => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+() => () => () => <div>Long long long long long, very very long text. And more text. Another text.</div>;
+
+<Prettier>
+  {We => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;
+<Prettier>
+  {We => love => currying => 'The purple monkey danced with a tambourine made of cheese.' + 'The robot chef cooked a cake that tasted like rainbows.' + 'The talking pineapple sang a lullaby to the sleepy giraffe.'}
+</Prettier>;