From ca4ef16c8f75d305c21145aecd304a82471492e6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Burzy=C5=84ski?= <mateuszburzynski@gmail.com>
Date: Tue, 23 Jul 2024 01:00:16 +0200
Subject: [PATCH] Fixed crash in `classFields` transform related to broken
 bodyless constructors (#59280)

Co-authored-by: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
---
 src/compiler/transformers/classFields.ts         |  4 ++--
 ...ieldsBrokenConstructorEmitNoCrash1.errors.txt | 14 ++++++++++++++
 .../classFieldsBrokenConstructorEmitNoCrash1.js  | 16 ++++++++++++++++
 ...ssFieldsBrokenConstructorEmitNoCrash1.symbols | 12 ++++++++++++
 ...lassFieldsBrokenConstructorEmitNoCrash1.types | 16 ++++++++++++++++
 .../classFieldsBrokenConstructorEmitNoCrash1.ts  |  8 ++++++++
 6 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.errors.txt
 create mode 100644 tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.js
 create mode 100644 tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.symbols
 create mode 100644 tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.types
 create mode 100644 tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts

diff --git a/src/compiler/transformers/classFields.ts b/src/compiler/transformers/classFields.ts
index 7ddafb36f7e..5a1b4321792 100644
--- a/src/compiler/transformers/classFields.ts
+++ b/src/compiler/transformers/classFields.ts
@@ -2416,11 +2416,11 @@ export function transformClassFields(context: TransformationContext): (x: Source
             factory.createBlock(
                 setTextRange(
                     factory.createNodeArray(statements),
-                    /*location*/ constructor ? constructor.body!.statements : node.members,
+                    /*location*/ constructor?.body?.statements ?? node.members,
                 ),
                 multiLine,
             ),
-            /*location*/ constructor ? constructor.body : undefined,
+            /*location*/ constructor?.body,
         );
     }
 
diff --git a/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.errors.txt b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.errors.txt
new file mode 100644
index 00000000000..882569d85c1
--- /dev/null
+++ b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.errors.txt
@@ -0,0 +1,14 @@
+classFieldsBrokenConstructorEmitNoCrash1.ts(3,3): error TS2390: Constructor implementation is missing.
+classFieldsBrokenConstructorEmitNoCrash1.ts(4,1): error TS1005: '(' expected.
+
+
+==== classFieldsBrokenConstructorEmitNoCrash1.ts (2 errors) ====
+    class Test {
+      prop = 42;
+      constructor
+      ~~~~~~~~~~~
+!!! error TS2390: Constructor implementation is missing.
+    }
+    ~
+!!! error TS1005: '(' expected.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.js b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.js
new file mode 100644
index 00000000000..4e12c57a8b2
--- /dev/null
+++ b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.js
@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts] ////
+
+//// [classFieldsBrokenConstructorEmitNoCrash1.ts]
+class Test {
+  prop = 42;
+  constructor
+}
+
+
+//// [classFieldsBrokenConstructorEmitNoCrash1.js]
+"use strict";
+class Test {
+    constructor() {
+        this.prop = 42;
+    }
+}
diff --git a/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.symbols b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.symbols
new file mode 100644
index 00000000000..4ea4711c805
--- /dev/null
+++ b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.symbols
@@ -0,0 +1,12 @@
+//// [tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts] ////
+
+=== classFieldsBrokenConstructorEmitNoCrash1.ts ===
+class Test {
+>Test : Symbol(Test, Decl(classFieldsBrokenConstructorEmitNoCrash1.ts, 0, 0))
+
+  prop = 42;
+>prop : Symbol(Test.prop, Decl(classFieldsBrokenConstructorEmitNoCrash1.ts, 0, 12))
+
+  constructor
+}
+
diff --git a/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.types b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.types
new file mode 100644
index 00000000000..6619167936e
--- /dev/null
+++ b/tests/baselines/reference/classFieldsBrokenConstructorEmitNoCrash1.types
@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts] ////
+
+=== classFieldsBrokenConstructorEmitNoCrash1.ts ===
+class Test {
+>Test : Test
+>     : ^^^^
+
+  prop = 42;
+>prop : number
+>     : ^^^^^^
+>42 : 42
+>   : ^^
+
+  constructor
+}
+
diff --git a/tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts b/tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts
new file mode 100644
index 00000000000..f9a9e712ccd
--- /dev/null
+++ b/tests/cases/compiler/classFieldsBrokenConstructorEmitNoCrash1.ts
@@ -0,0 +1,8 @@
+// @strict: true
+// @useDefineForClassFields: false
+// @target: es2021
+
+class Test {
+  prop = 42;
+  constructor
+}