Check for initializer before using it (#18708)

Author: mhegazy

src/compiler/checker.ts

@@ -16491,7 +16491,7 @@ namespace ts {
 
                 // If the symbol of the node has members, treat it like a constructor.
                 const symbol = isFunctionDeclaration(node) || isFunctionExpression(node) ? getSymbolOfNode(node) :
-                     isVariableDeclaration(node) && isFunctionExpression(node.initializer) ? getSymbolOfNode(node.initializer) :
+                     isVariableDeclaration(node) && node.initializer && isFunctionExpression(node.initializer) ? getSymbolOfNode(node.initializer) :
                      undefined;
 
                 return symbol && symbol.members !== undefined;

tests/baselines/reference/constructorFunctions.symbols

@@ -74,3 +74,23 @@ const c4_v2 = new C4();
 >c4_v2 : Symbol(c4_v2, Decl(index.js, 30, 5))
 >C4 : Symbol(C4, Decl(index.js, 25, 3))
 
+var c5_v1;
+>c5_v1 : Symbol(c5_v1, Decl(index.js, 32, 3))
+
+c5_v1 = function f() { };
+>c5_v1 : Symbol(c5_v1, Decl(index.js, 32, 3))
+>f : Symbol(f, Decl(index.js, 33, 7))
+
+new c5_v1();
+>c5_v1 : Symbol(c5_v1, Decl(index.js, 32, 3))
+
+var c5_v2;
+>c5_v2 : Symbol(c5_v2, Decl(index.js, 36, 3))
+
+c5_v2 = class { };
+>c5_v2 : Symbol(c5_v2, Decl(index.js, 36, 3))
+
+new c5_v2();
+>c5_v2 : Symbol(c5_v2, Decl(index.js, 36, 3))
+
+

tests/baselines/reference/constructorFunctions.types

@@ -112,3 +112,29 @@ const c4_v2 = new C4();
 >new C4() : {}
 >C4 : () => any
 
+var c5_v1;
+>c5_v1 : any
+
+c5_v1 = function f() { };
+>c5_v1 = function f() { } : () => void
+>c5_v1 : any
+>function f() { } : () => void
+>f : () => void
+
+new c5_v1();
+>new c5_v1() : any
+>c5_v1 : () => void
+
+var c5_v2;
+>c5_v2 : any
+
+c5_v2 = class { };
+>c5_v2 = class { } : typeof (Anonymous class)
+>c5_v2 : any
+>class { } : typeof (Anonymous class)
+
+new c5_v2();
+>new c5_v2() : (Anonymous class)
+>c5_v2 : typeof (Anonymous class)
+
+

tests/cases/conformance/salsa/constructorFunctions.ts

@@ -33,4 +33,13 @@ var C4 = function () {
 };
 
 const c4_v1 = C4();
-const c4_v2 = new C4();
+const c4_v2 = new C4();
+
+var c5_v1;
+c5_v1 = function f() { };
+new c5_v1();
+
+var c5_v2;
+c5_v2 = class { };
+new c5_v2();
+