added dump/error2b endpoint for apitest in fylr

see #75661

Author: martinrode

manifest.master.yml

@@ -122,6 +122,19 @@ extensions:
             - type: "value"
               value: "%_exec.pluginDir%/server/extension/error2.js"
 
+  dump/error2b:
+    exec:
+      service: "node"
+      commands:
+        - prog: "node"
+          stdin:
+            type: "body"
+          stdout:
+            type: "body"
+          args:
+            - type: "value"
+              value: "%_exec.pluginDir%/server/extension/error2b.js"
+
   dump/error3:
     exec:
       service: "node"

server/extension/error2b.js

@@ -0,0 +1,13 @@
+(()=> {
+    console.log(JSON.stringify(
+      {
+        "code": "custom.error",
+        "err": "custom err", // this used to cause a parser error
+        "error": "custom error",
+        "statuscode": 402
+      }
+    ))
+    console.error("This error goes to STDERR")
+    // pass status code here
+    process.exit(499)
+})()