Update topenAIChat.m

Author: vpapanasta

tests/topenAIChat.m

@@ -3,18 +3,6 @@
 
 %   Copyright 2023-2024 The MathWorks, Inc.
 
-    methods (TestClassSetup)
-        function saveEnvVar(testCase)
-            % Ensures key is not in environment variable for tests
-            openAIEnvVar = "OPENAI_API_KEY";
-            if isenv(openAIEnvVar)
-                key = getenv(openAIEnvVar);
-                unsetenv(openAIEnvVar);
-                testCase.addTeardown(@(x) setenv(openAIEnvVar, x), key);
-            end
-        end
-    end
-
     properties(TestParameter)
         InvalidConstructorInput = iGetInvalidConstructorInput();
         InvalidGenerateInput = iGetInvalidGenerateInput();  
@@ -44,6 +32,7 @@ function generateOpenAIChatWithDefaultNVPValues(testCase)
         end
 
         function keyNotFound(testCase)
+            iSaveEnvVar(testCase);
             testCase.verifyError(@()openAIChat, "llms:keyMustBeSpecified");
         end
 
@@ -469,4 +458,14 @@ function createOpenAIChatWithOpenAIKey(testCase)
         "InvalidSeed",struct( ...
             "Input",{{ validMessages  "Seed" "2" }},...
             "Error","MATLAB:validators:mustBeNumericOrLogical"));   
+end
+
+function iSaveEnvVar(testCase)
+% Ensures key is not in environment variable for tests
+openAIEnvVar = "OPENAI_API_KEY";
+if isenv(openAIEnvVar)
+    key = getenv(openAIEnvVar);
+    unsetenv(openAIEnvVar);
+    testCase.addTeardown(@(x) setenv(openAIEnvVar, x), key);
+end
 end