Add ./jest.config.js to include

in tsconfig.json

tsconfig.json

@@ -106,5 +106,5 @@
     // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
     "skipLibCheck": true /* Skip type checking all .d.ts files. */
   },
-  "include": ["src/**/*.ts", "tests/**/*.ts"]
+  "include": ["src/**/*.ts", "tests/**/*.ts", "./jest.config.js"]
 }