🐛 [RUMF-1470] Sanitize - Fix size computation

packages/core/src/tools/sanitize.spec.ts

@@ -112,6 +112,11 @@ describe('sanitize', () => {
 
       expect(sanitize(cannotSerialize)).toEqual('[Unserializable]')
     })
+
+    it('should handle objects with properties including null or undefined', () => {
+      const obj = { a: null, b: undefined }
+      expect(sanitize(obj)).toEqual({ a: null, b: undefined })
+    })
   })
 
   describe('arrays handling', () => {
@@ -122,6 +127,11 @@ describe('sanitize', () => {
 
       expect(sanitize(arr)).toEqual([1, 2, 3, 4])
     })
+
+    it('should handle arrays containing null or undefined', () => {
+      const arr = [null, undefined]
+      expect(sanitize(arr)).toEqual([null, undefined])
+    })
   })
 
   describe('circular references handling', () => {
@@ -240,5 +250,22 @@ describe('sanitize', () => {
       expect(sanitized).toEqual([1, 2]) // Length of 5 after JSON.stringify
       expect(displaySpy).toHaveBeenCalled()
     })
+
+    it('should count size properly when array contains undefined values', () => {
+      // This is a special case: JSON.stringify([undefined]) => '[null]'
+      const displaySpy = spyOn(display, 'warn')
+      const arr = [undefined, undefined] // Length of 11 after JSON.stringify
+      const sanitized = sanitize(arr, 10)
+      expect(sanitized).toEqual([undefined])
+      expect(displaySpy).toHaveBeenCalled()
+    })
+
+    it('should count size properly when an object contains properties with undefined values', () => {
+      const displaySpy = spyOn(display, 'warn')
+      const obj = { a: undefined, b: 42 } // Length of 8 after JSON.stringify
+      const sanitized = sanitize(obj, 8)
+      expect(sanitized).toEqual({ a: undefined, b: 42 })
+      expect(displaySpy).not.toHaveBeenCalled()
+    })
   })
 })

packages/core/src/tools/sanitize.ts

@@ -79,12 +79,20 @@ export function sanitize(source: unknown, maxCharacterCount = SANITIZE_DEFAULT_M
           containerQueue,
           visitedObjectsWithPath
         )
-        accumulatedCharacterCount += JSON.stringify(targetData).length + separatorLength
+
+        if (targetData !== undefined) {
+          accumulatedCharacterCount += JSON.stringify(targetData).length
+        } else {
+          // When an element of an Array (targetData) is undefined, it is serialized as null:
+          // JSON.stringify([undefined]) => '[null]' - This accounts for 4 characters
+          accumulatedCharacterCount += 4
+        }
+        accumulatedCharacterCount += separatorLength
+        separatorLength = 1
         if (accumulatedCharacterCount > maxCharacterCount) {
           warnOverCharacterLimit(maxCharacterCount, 'truncated', source)
           break
         }
-        separatorLength = 1
         ;(containerToProcess.target as ContextArray)[key] = targetData
       }
     } else {
@@ -97,13 +105,17 @@ export function sanitize(source: unknown, maxCharacterCount = SANITIZE_DEFAULT_M
             containerQueue,
             visitedObjectsWithPath
           )
-          accumulatedCharacterCount +=
-            JSON.stringify(targetData).length + separatorLength + key.length + KEY_DECORATION_LENGTH
+          // When a property of an object has an undefined value, it will be dropped during serialization:
+          // JSON.stringify({a:undefined}) => '{}'
+          if (targetData !== undefined) {
+            accumulatedCharacterCount +=
+              JSON.stringify(targetData).length + separatorLength + key.length + KEY_DECORATION_LENGTH
+            separatorLength = 1
+          }
           if (accumulatedCharacterCount > maxCharacterCount) {
             warnOverCharacterLimit(maxCharacterCount, 'truncated', source)
             break
           }
-          separatorLength = 1
           ;(containerToProcess.target as Context)[key] = targetData
         }
       }