fix: eval context fixes and new error types

open_feature/evaluation_context/evaluation_context.py

@@ -7,7 +7,7 @@ def merge(self, ctx2: "EvaluationContext") -> "EvaluationContext":
         if not (self and ctx2):
             return self or ctx2
 
-        self.attributes = {**self.attributes, **ctx2.attributes}
-        self.targeting_key = ctx2.targeting_key or self.targeting_key
+        attributes = {**self.attributes, **ctx2.attributes}
+        targeting_key = ctx2.targeting_key or self.targeting_key
 
-        return self
+        return EvaluationContext(targeting_key=targeting_key, attributes=attributes)

open_feature/exception/exceptions.py

@@ -85,3 +85,35 @@ def __init__(self, error_message: str = None):
         @return: the generic TypeMismatchError exception
         """
         super().__init__(error_message, ErrorCode.TYPE_MISMATCH)
+
+
+class TargetingKeyMissingError(OpenFeatureError):
+    """
+    This exception should be raised when the provider requires a targeting key
+    but one was not provided in the evaluation context.
+    """
+
+    def __init__(self, error_message: str = None):
+        """
+        Constructor for the TargetingKeyMissingError. The error code for this type of
+        exception is ErrorCode.TARGETING_KEY_MISSING.
+        @param error_message: a string message representing why the error has been
+        raised
+        """
+        super().__init__(error_message, ErrorCode.TARGETING_KEY_MISSING)
+
+
+class InvalidContextError(OpenFeatureError):
+    """
+    This exception should be raised when the evaluation context does not meet provider
+    requirements.
+    """
+
+    def __init__(self, error_message: str = None):
+        """
+        Constructor for the InvalidContextError. The error code for this type of
+        exception is ErrorCode.INVALID_CONTEXT.
+        @param error_message: a string message representing why the error has been
+        raised
+        """
+        super().__init__(error_message, ErrorCode.INVALID_CONTEXT)

open_feature/flag_evaluation/error_code.py

@@ -6,4 +6,6 @@ class ErrorCode(Enum):
     FLAG_NOT_FOUND = "FLAG_NOT_FOUND"
     PARSE_ERROR = "PARSE_ERROR"
     TYPE_MISMATCH = "TYPE_MISMATCH"
+    TARGETING_KEY_MISSING = "TARGETING_KEY_MISSING"
+    INVALID_CONTEXT = "INVALID_CONTEXT"
     GENERAL = "GENERAL"

open_feature/open_feature_client.py

@@ -199,7 +199,7 @@ def evaluate_flag_details(
             invocation_context = before_hooks(
                 flag_type, hook_context, merged_hooks, None
             )
-            invocation_context.merge(ctx2=evaluation_context)
+            invocation_context = invocation_context.merge(ctx2=evaluation_context)
 
             # merge of: API.context, client.context, invocation.context
             merged_context = (