From 5652085eb4d884f300a7db7f2dbc522ecacd2e8e Mon Sep 17 00:00:00 2001
From: Peter Dvorak <peter.dvorak@novo.sk>
Date: Wed, 1 Jul 2026 09:46:06 +0200
Subject: [PATCH] Fix checker crashes silently passing validation as valid

  The two catch blocks in checkBehaviorReport() assumed every caught
  error was a custom {path, error} object (as thrown by
  Behavior.createStructureInfo / checkStatemachine). A real JS exception
  (e.g. a TypeError from a bug in the checker) has no .error property, so:

    - checking.js:189 pushed `error.error` == undefined onto
      report.fatal_errors. checkBehavior() then returns fatal_errors[0]
      == undefined, which callers read as "no error" -> a behavior that
      actually failed the check could be saved or started as if valid.

    - checking.js:199 called `error.path.replace(...)` unconditionally.
      On a real exception .path is undefined, so this threw a second
      TypeError inside the catch handler, masking the original error.

  Both handlers now resolve a non-empty message
  (error.error -> error.message -> String(error)), so a checker crash
  always produces a real fatal error instead of undefined. The
  container-navigation logic is guarded by `if (error.path != undefined)`
  so it only runs for the custom {path, error} objects that carry a path.
---
 flexbe_webui/app/_helper/checking.js | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/flexbe_webui/app/_helper/checking.js b/flexbe_webui/app/_helper/checking.js
index 71e31a5..d39f620 100644
--- a/flexbe_webui/app/_helper/checking.js
+++ b/flexbe_webui/app/_helper/checking.js
@@ -186,7 +186,8 @@ const Checking = new (function() {
 		} catch (error) {
 			console.log(`\x1b[91m Failed behavior check for '${Behavior.getBehaviorName()}\x1b[0m'\n    ${error}`);
 			console.log(error.stack);
-			report.fatal_errors.push(error.error);
+			// error may be a custom {path, error} object or a real JS exception; always record a non-empty message
+			report.fatal_errors.push(error.error != undefined ? error.error : (error.message != undefined ? error.message : `${error}`));
 			return report;
 		}
 
@@ -196,16 +197,21 @@ const Checking = new (function() {
 		} catch (error) {
 			console.log(`\x1b[91m Failed behavior createStructureInfo for '${Behavior.getBehaviorName()}\x1b[0m'\n    ${error}`);
 			console.log(error.stack);
-			let container_path = error.path.replace("/"+error.path.split("/").pop(), "");
-			let container = Behavior.getStatemachine().getStateByPath(container_path);
-			if (container instanceof BehaviorState) {
-				error.error += "<br />Note: Since this error is inside a contained behavior, please open this behavior directly and fix it there.";
-				error.error += "<br />Affected behavior: " + container.getBehaviorName();
-				container = container.getBehaviorStatemachine();
-			}
-			UI.Statemachine.setDisplayedSM(container);
+			// error may be a custom {path, error} object or a real JS exception; resolve a non-empty message and only
+			// navigate to the offending container when a path is actually present (a real exception has none).
+			let error_message = error.error != undefined ? error.error : (error.message != undefined ? error.message : `${error}`);
+			if (error.path != undefined) {
+				let container_path = error.path.replace("/"+error.path.split("/").pop(), "");
+				let container = Behavior.getStatemachine().getStateByPath(container_path);
+				if (container instanceof BehaviorState) {
+					error_message += "<br />Note: Since this error is inside a contained behavior, please open this behavior directly and fix it there.";
+					error_message += "<br />Affected behavior: " + container.getBehaviorName();
+					container = container.getBehaviorStatemachine();
+				}
+				UI.Statemachine.setDisplayedSM(container);
+			}
 			UI.Menu.toStatemachineClicked();
-			report.fatal_errors.push(error.error);
+			report.fatal_errors.push(error_message);
 			return report;
 		}