adding check (#1957)

Signed-off-by: svetoslav-nikol0v <[email protected]>

examples/.env.example

@@ -0,0 +1,2 @@
+# Variable used in script that runs all examples
+NODE_COMMAND=node

examples/run-all-examples.js

@@ -13,13 +13,18 @@ const excludedDirectories = [
     "./simple_rest_signature_provider",
 ];
 const excludedJSFile = "run-all-examples.js";
+const cmd = process.env.NODE_COMMAND;
 
 fs.readdir(examplesDirectory, (err, files) => {
     if (err) {
         console.error("Error reading directory:", err);
         return;
     }
 
+    if (cmd === undefined) {
+        throw new Error("Environment variable NODE_COMMAND is required.");
+    }
+
     let completed = 0;
     let failed = 0;
 
@@ -43,7 +48,7 @@ fs.readdir(examplesDirectory, (err, files) => {
         console.log(`\n⏳ ${index + 1}. Running ${file}...`);
         const examplePath = path.join(examplesDirectory, file);
 
-        const result = spawnSync(process.env.NODE_COMMAND, [examplePath], {
+        const result = spawnSync(cmd, [examplePath], {
             stdio: "ignore",
         });