From ebe9ee29b0db4aa3dd86a19ece2dca0d7404f217 Mon Sep 17 00:00:00 2001
From: poteboy <poteboy.dev@gmail.com>
Date: Wed, 31 Jul 2024 23:36:14 +0900
Subject: [PATCH 1/2] feat: Fix parsing of generic type parameters in arrow
 functions with JSX syntax

---
 src/compiler/parser.ts                              |  9 +++++++++
 .../reference/jsxGenericArrowFunction.symbols       | 10 ++++++++++
 .../reference/jsxGenericArrowFunction.types         | 13 +++++++++++++
 tests/cases/compiler/jsxGenericArrowFunction.tsx    |  5 +++++
 4 files changed, 37 insertions(+)
 create mode 100644 tests/baselines/reference/jsxGenericArrowFunction.symbols
 create mode 100644 tests/baselines/reference/jsxGenericArrowFunction.types
 create mode 100644 tests/cases/compiler/jsxGenericArrowFunction.tsx

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index b20d4b8b8b52e..09ee76a8e9258 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -5352,6 +5352,15 @@ namespace Parser {
                     return Tristate.True;
                 }
 
+                const isNextTokenGreater = lookAhead(function () {
+                    var third = nextToken();
+                    return third === SyntaxKind.GreaterThanToken;
+                });
+
+                if (isNextTokenGreater) {
+                    return Tristate.Unknown;
+                }
+
                 return Tristate.False;
             }
 
diff --git a/tests/baselines/reference/jsxGenericArrowFunction.symbols b/tests/baselines/reference/jsxGenericArrowFunction.symbols
new file mode 100644
index 0000000000000..f24a510b4be75
--- /dev/null
+++ b/tests/baselines/reference/jsxGenericArrowFunction.symbols
@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/jsxGenericArrowFunction.tsx] ////
+
+=== jsxGenericArrowFunction.tsx ===
+const a = <T>(b: T) => b
+>a : Symbol(a, Decl(jsxGenericArrowFunction.tsx, 0, 5))
+>T : Symbol(T, Decl(jsxGenericArrowFunction.tsx, 0, 11))
+>b : Symbol(b, Decl(jsxGenericArrowFunction.tsx, 0, 14))
+>T : Symbol(T, Decl(jsxGenericArrowFunction.tsx, 0, 11))
+>b : Symbol(b, Decl(jsxGenericArrowFunction.tsx, 0, 14))
+
diff --git a/tests/baselines/reference/jsxGenericArrowFunction.types b/tests/baselines/reference/jsxGenericArrowFunction.types
new file mode 100644
index 0000000000000..507ba00c7dc7b
--- /dev/null
+++ b/tests/baselines/reference/jsxGenericArrowFunction.types
@@ -0,0 +1,13 @@
+//// [tests/cases/compiler/jsxGenericArrowFunction.tsx] ////
+
+=== jsxGenericArrowFunction.tsx ===
+const a = <T>(b: T) => b
+>a : <T>(b: T) => T
+>  : ^ ^^ ^^ ^^^^^^
+><T>(b: T) => b : <T>(b: T) => T
+>               : ^ ^^ ^^ ^^^^^^
+>b : T
+>  : ^
+>b : T
+>  : ^
+
diff --git a/tests/cases/compiler/jsxGenericArrowFunction.tsx b/tests/cases/compiler/jsxGenericArrowFunction.tsx
new file mode 100644
index 0000000000000..0ac51630b5995
--- /dev/null
+++ b/tests/cases/compiler/jsxGenericArrowFunction.tsx
@@ -0,0 +1,5 @@
+// @strict: true
+// @noEmit: true
+// @jsx: preserve
+
+const a = <T>(b: T) => b
\ No newline at end of file

From c6057c0b97bf16572fd371dbead00676dc9685df Mon Sep 17 00:00:00 2001
From: poteboy <poteboy.dev@gmail.com>
Date: Wed, 31 Jul 2024 23:53:45 +0900
Subject: [PATCH 2/2] chore: Run lint

---
 src/compiler/parser.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 09ee76a8e9258..a7bddf7ef93ec 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -5352,8 +5352,8 @@ namespace Parser {
                     return Tristate.True;
                 }
 
-                const isNextTokenGreater = lookAhead(function () {
-                    var third = nextToken();
+                const isNextTokenGreater = lookAhead(() => {
+                    const third = nextToken();
                     return third === SyntaxKind.GreaterThanToken;
                 });