Add isCJS helper, update import-in-the-middle

library/agent/hooks/wrapRequire.ts

@@ -34,6 +34,7 @@ export function wrapRequire() {
       `Could not find the _resolveFilename function in node:module using Node.js version ${process.version}`
     );
   }
+
   // Prevent wrapping the require function multiple times
   isRequireWrapped = true;
   // Save the original require function
@@ -261,5 +262,5 @@ function patchPackage(this: mod, id: string, originalExports: unknown) {
  * Returns the unwrapped require function.
  */
 export function getOrignalRequire() {
-  return originalRequire || mod.prototype.require;
+  return originalRequire || mod.prototype?.require;
 }

library/helpers/isCJS.ts

@@ -0,0 +1,9 @@
+import * as mod from "module";
+
+/**
+ * Check if executed in CommonJS environment.
+ * This will always be true if the library is normally used because it is a CommonJS library.
+ */
+export function isCJS(): boolean {
+  return mod.prototype !== undefined && mod.prototype.require !== undefined;
+}