Fix panic in getTsConfigObjectLiteralExpression for malformed tsconfig (#3877)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: DanielRosenwasser <972891+DanielRosenwasser@users.noreply.github.com>

Author: Copilot

internal/tsoptions/tsconfigparsing.go

@@ -1505,7 +1505,9 @@ func ForEachPropertyAssignment[T any](objectLiteral *ast.ObjectLiteralExpression
 func getTsConfigObjectLiteralExpression(tsConfigSourceFile *ast.SourceFile) *ast.ObjectLiteralExpression {
 	if tsConfigSourceFile != nil && tsConfigSourceFile.Statements != nil && len(tsConfigSourceFile.Statements.Nodes) > 0 {
 		expression := tsConfigSourceFile.Statements.Nodes[0].Expression()
-		return expression.AsObjectLiteralExpression()
+		if ast.IsObjectLiteralExpression(expression) {
+			return expression.AsObjectLiteralExpression()
+		}
 	}
 	return nil
 }

testdata/baselines/reference/compiler/tsconfigMalformedNonObject.errors.txt

@@ -0,0 +1,13 @@
+error TS2688: Cannot find type definition file for 'nonexistent'.
+  The file is in the program because:
+    Entry point of type library 'nonexistent' specified in compilerOptions
+
+
+!!! error TS2688: Cannot find type definition file for 'nonexistent'.
+!!! error TS2688:   The file is in the program because:
+!!! error TS2688:     Entry point of type library 'nonexistent' specified in compilerOptions
+==== tsconfig.json (0 errors) ====
+    [{"compilerOptions": {"types": ["nonexistent"]}}]
+==== index.ts (0 errors) ====
+    export const x = 1;
+    

testdata/baselines/reference/compiler/tsconfigMalformedNonObject.js

@@ -0,0 +1,8 @@
+//// [tests/cases/compiler/tsconfigMalformedNonObject.ts] ////
+
+//// [index.ts]
+export const x = 1;
+
+
+//// [index.js]
+export const x = 1;

testdata/baselines/reference/compiler/tsconfigMalformedNonObject.symbols

@@ -0,0 +1,6 @@
+//// [tests/cases/compiler/tsconfigMalformedNonObject.ts] ////
+
+=== index.ts ===
+export const x = 1;
+>x : Symbol(x, Decl(index.ts, 0, 12))
+

testdata/baselines/reference/compiler/tsconfigMalformedNonObject.types

@@ -0,0 +1,7 @@
+//// [tests/cases/compiler/tsconfigMalformedNonObject.ts] ////
+
+=== index.ts ===
+export const x = 1;
+>x : 1
+>1 : 1
+

testdata/tests/cases/compiler/tsconfigMalformedNonObject.ts

@@ -0,0 +1,4 @@
+// @filename: tsconfig.json
+[{"compilerOptions": {"types": ["nonexistent"]}}]
+// @filename: index.ts
+export const x = 1;