fix(npm): do not assume error code is a string (#120)

Fixes #119

Author: mcous

Diff for: dist/main.js

@@ -71,12 +71,15 @@ export async function callNpmCli<CommandT extends Command>(
   if (exitCode === 0) {
     successData = parseJson<SuccessData<CommandT>>(stdout);
   } else {
-    const errorPayload = parseJson<{ error?: { code?: string | null } }>(
+    const errorPayload = parseJson<{ error?: { code?: unknown } }>(
       stdout,
       stderr
     );
 
-    errorCode = errorPayload?.error?.code?.toUpperCase();
+    if (errorPayload?.error?.code) {
+      errorCode = String(errorPayload.error.code).toUpperCase();
+    }
+
     error = new errors.NpmCallError(command, exitCode, stderr);
   }
 
@@ -109,6 +112,9 @@ async function execNpm(
     npm.stdout.on("data", (data) => (stdout += data));
     npm.stderr.on("data", (data) => (stderr += data));
     npm.on("close", (code) => {
+      logger?.debug?.(`Received stdout: ${stdout}`);
+      logger?.debug?.(`Received stderr: ${stderr}`);
+
       resolve({
         stdout: stdout.trim(),
         stderr: stderr.trim(),