[]: Fix test context files

1 files changed, 3 insertions, 1 deletions

diff --git a/library/python/testing/yatest_lib/ya.py b/library/python/testing/yatest_lib/ya.py
index dc4011db92..ab1a5366f2 100644
--- a/library/python/testing/yatest_lib/ya.py
+++ b/library/python/testing/yatest_lib/ya.py
@@ -102,7 +102,9 @@ class Ya(object):
         self._env_file = context_internal.get("env_file")
 
         if context:
-            self._context.update(context)
+            for k, v in context.items():
+                if k not in self._context or v is not None:
+                    self._context[k] = v
 
     @property
     def source_root(self):