Regression - JSON null matching (1.5.2 -2.0.x)

[ChristianAA]

Description

• In Karate 1.5.2 the assertion And match x.x == null succeeded when the response contained a real JSON null.
• In Karate 2.0.X the same assertion fails
• A workaround that passes is And match x.x == '#notpresent'.

Steps to Reproduce

Steps

1. Create a feature with the minimal scenario below.
2. Run the feature against Karate 1.5.2 and then against Karate 2.0.X.

Minimal reproduction

Feature: null matching regression demo

  Scenario: match real null values
	* def response = { status: 'ERROR_CREATING', user: null, settings: null }
	Then match response.status == 'ERROR_CREATING'
	And match response.user == null
	And match response.settings == null

Expected Behavior

The following worked in 1.5.2:

Then match response.user == null
And match response.settings == null

Actual Behavior

Error message:

Then match response.user == null
  match failed: EQUALS
  $ | actual path does not exist (STRING:NULL)
  '#notpresent'
  null

Karate Version

2.0.6

Java Version

25

Operating System

Linux

[ptrthomas]

Fixed on main in 2550735 — will ship in 2.0.7. The root cause was a heuristic in the match-expression evaluator that used a JS 'propName' in basePath check to differentiate "missing key" from "present-but-null"; that operator misreports Java Map keys, so a real null property was being coerced to #notpresent. Replaced with a direct Map.containsKey lookup.