Upgrade TypeScript to v4

Author: Evgeniy Timokhov

package.json

@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/timocov/ts-transformer-properties-rename",
   "peerDependencies": {
-    "typescript": ">=3.0.0"
+    "typescript": ">=3.0.0 || >=4.0.0"
   },
   "devDependencies": {
     "@types/chai": "~4.2.11",
@@ -38,7 +38,7 @@
     "rimraf": "~3.0.2",
     "ts-node": "~8.10.2",
     "tslint": "~6.1.2",
-    "typescript": "~3.9.5"
+    "typescript": "~4.4.3"
   },
   "scripts": {
     "clean": "rimraf lib/ dist/",

src/typescript-helpers.ts

@@ -121,7 +121,8 @@ export function getClassOfMemberSymbol(nodeSymbol: ts.Symbol): ts.ClassLikeDecla
 			return (classMember.parent as ts.ConstructorDeclaration).parent;
 		}
 
-		return classMember.parent;
+		// we're sure that it is a class, not interface
+		return classMember.parent as ts.ClassLikeDeclaration | ts.ObjectLiteralExpression;
 	}
 
 	return null;