From 9eb6424b8f6244b9a74cbea47c76b209c41b2cef Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrewbranch@users.noreply.github.com>
Date: Tue, 22 Sep 2020 17:16:09 -0700
Subject: [PATCH] Fix indentation of arrow functions returning parenthesized
 expressions (#40677)

* Fix indentation of arrow functions returning parenthesized expressions

* Add more test cases
---
 src/harness/fourslashImpl.ts                  |  3 +-
 src/services/formatting/smartIndenter.ts      |  6 ++-
 ...ingArrowFunctionParenthesizedExpression.ts | 47 +++++++++++++++++++
 3 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 tests/cases/fourslash/formattingArrowFunctionParenthesizedExpression.ts

diff --git a/src/harness/fourslashImpl.ts b/src/harness/fourslashImpl.ts
index 299403d8974..a87d0a9e1da 100644
--- a/src/harness/fourslashImpl.ts
+++ b/src/harness/fourslashImpl.ts
@@ -2461,8 +2461,7 @@ namespace FourSlash {
             const { fileName } = this.activeFile;
             const before = this.getFileContent(fileName);
             this.formatDocument();
-            const after = this.getFileContent(fileName);
-            this.assertObjectsEqual(after, before);
+            this.verifyFileContent(fileName, before);
         }
 
         public verifyTextAtCaretIs(text: string) {
diff --git a/src/services/formatting/smartIndenter.ts b/src/services/formatting/smartIndenter.ts
index 23011643811..b8af97350f7 100644
--- a/src/services/formatting/smartIndenter.ts
+++ b/src/services/formatting/smartIndenter.ts
@@ -558,11 +558,15 @@ namespace ts.formatting {
                 case SyntaxKind.FunctionDeclaration:
                 case SyntaxKind.FunctionExpression:
                 case SyntaxKind.MethodDeclaration:
-                case SyntaxKind.ArrowFunction:
                 case SyntaxKind.Constructor:
                 case SyntaxKind.GetAccessor:
                 case SyntaxKind.SetAccessor:
                     return childKind !== SyntaxKind.Block;
+                case SyntaxKind.ArrowFunction:
+                    if (sourceFile && childKind === SyntaxKind.ParenthesizedExpression) {
+                        return rangeIsOnOneLine(sourceFile, child!);
+                    }
+                    return childKind !== SyntaxKind.Block;
                 case SyntaxKind.ExportDeclaration:
                     return childKind !== SyntaxKind.NamedExports;
                 case SyntaxKind.ImportDeclaration:
diff --git a/tests/cases/fourslash/formattingArrowFunctionParenthesizedExpression.ts b/tests/cases/fourslash/formattingArrowFunctionParenthesizedExpression.ts
new file mode 100644
index 00000000000..de1021bf1c6
--- /dev/null
+++ b/tests/cases/fourslash/formattingArrowFunctionParenthesizedExpression.ts
@@ -0,0 +1,47 @@
+/// <reference path="fourslash.ts" />
+
+// @Filename: Bar.tsx
+//// export const Bar = ({
+////     foo,
+////     bar,
+//// }: any) => (
+////     <div>Hello world</div>
+//// )
+//// 
+//// export const Bar2 = ({
+////     foo,
+////     bar,
+//// }) => (<div>Hello world</div>)
+////
+//// export const Bar2 = ({
+////     foo,
+////     bar,
+//// }) => <div>Hello world</div>
+//// 
+//// export const Bar3 = ({
+////     foo,
+////     bar,
+//// }) =>
+////     (<div>Hello world</div>)
+////
+//// export const Bar4 = ({
+////     foo,
+////     bar,
+//// }) =>
+////     <div>Hello world</div>
+////
+//// export const Bar5 = () => (
+////     <div>Hello world</div>
+//// )
+//// 
+//// export const Bar6 = () => (<div>Hello world</div>)
+//// 
+//// export const Bar7 = () => <div>Hello world</div>
+//// 
+//// export const Bar8 = () =>
+////     (<div>Hello world</div>)
+//// 
+//// export const Bar9 = () =>
+////     <div>Hello world</div>
+
+verify.formatDocumentChangesNothing();