Log a clear error in the console when the returned value of `onEditable` is invalid. See #1112

HISTORY.md

@@ -3,6 +3,12 @@
 https://github.com/josdejong/jsoneditor
 
 
+## not yet published, version 9.1.2
+
+- Log a clear error in the console when the returned value of `onEditable` is 
+  invalid. See #1112.
+
+
 ## 2020-09-23, version 9.1.1
 
 - Fix #1111: Enum dropdown not showing when using patternProperties for schema.

src/js/Node.js

@@ -104,9 +104,16 @@ export class Node {
         if (typeof editable === 'boolean') {
           this.editable.field = editable
           this.editable.value = editable
-        } else {
+        } else if (typeof editable === 'object' && editable !== null) {
           if (typeof editable.field === 'boolean') this.editable.field = editable.field
           if (typeof editable.value === 'boolean') this.editable.value = editable.value
+        } else {
+          console.error( 'Invalid return value for function onEditable. ' +
+            'Actual value:', editable, '.',
+            'Either a boolean or object { field: boolean, value: boolean } expected.')
+
+          this.editable.field = false
+          this.editable.value = false
         }
       }
     }