From cdf12f91c73c641738c2a3c57607986fb29321f3 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Tue, 30 Nov 2021 12:57:37 -0800
Subject: [PATCH] Fix parsing of parenthesized functions in conditional
 expressions (#46960)

---
 src/compiler/parser.ts                              |  3 ++-
 ...izedVariableAndParenthesizedFunctionInTernary.js |  8 ++++++++
 ...ariableAndParenthesizedFunctionInTernary.symbols |  8 ++++++++
 ...dVariableAndParenthesizedFunctionInTernary.types | 13 +++++++++++++
 ...izedVariableAndParenthesizedFunctionInTernary.ts |  2 ++
 5 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.js
 create mode 100644 tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.symbols
 create mode 100644 tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.types
 create mode 100644 tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 6bb5d0aec31b9..9ca4828fec111 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -4539,9 +4539,10 @@ namespace ts {
             //  - "(x,y)" is a comma expression parsed as a signature with two parameters.
             //  - "a ? (b): c" will have "(b):" parsed as a signature with a return type annotation.
             //  - "a ? (b): function() {}" will too, since function() is a valid JSDoc function type.
+            //  - "a ? (b): (function() {})" as well, but inside of a parenthesized type.
             //
             // So we need just a bit of lookahead to ensure that it can only be a signature.
-            const hasJSDocFunctionType = type && isJSDocFunctionType(type);
+            const hasJSDocFunctionType = type && (isJSDocFunctionType(type) || isParenthesizedTypeNode(type) && isJSDocFunctionType(type.type));
             if (!allowAmbiguity && token() !== SyntaxKind.EqualsGreaterThanToken && (hasJSDocFunctionType || token() !== SyntaxKind.OpenBraceToken)) {
                 // Returning undefined here will cause our caller to rewind to where we started from.
                     return undefined;
diff --git a/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.js b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.js
new file mode 100644
index 0000000000000..2aa4a3989b9fa
--- /dev/null
+++ b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.js
@@ -0,0 +1,8 @@
+//// [parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts]
+let a: any;
+const c = true ? (a) : (function() {});
+
+
+//// [parserParenthesizedVariableAndParenthesizedFunctionInTernary.js]
+var a;
+var c = true ? (a) : (function () { });
diff --git a/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.symbols b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.symbols
new file mode 100644
index 0000000000000..9e2db3a1f667b
--- /dev/null
+++ b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts ===
+let a: any;
+>a : Symbol(a, Decl(parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts, 0, 3))
+
+const c = true ? (a) : (function() {});
+>c : Symbol(c, Decl(parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts, 1, 5))
+>a : Symbol(a, Decl(parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts, 0, 3))
+
diff --git a/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.types b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.types
new file mode 100644
index 0000000000000..5d9ee98ad924a
--- /dev/null
+++ b/tests/baselines/reference/parserParenthesizedVariableAndParenthesizedFunctionInTernary.types
@@ -0,0 +1,13 @@
+=== tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts ===
+let a: any;
+>a : any
+
+const c = true ? (a) : (function() {});
+>c : any
+>true ? (a) : (function() {}) : any
+>true : true
+>(a) : any
+>a : any
+>(function() {}) : () => void
+>function() {} : () => void
+
diff --git a/tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts b/tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts
new file mode 100644
index 0000000000000..6b22d3dd12cdf
--- /dev/null
+++ b/tests/cases/conformance/parser/ecmascript5/parserParenthesizedVariableAndParenthesizedFunctionInTernary.ts
@@ -0,0 +1,2 @@
+let a: any;
+const c = true ? (a) : (function() {});