Warning and control the rest of interfaces in GRPCCall+Tests as well

src/objective-c/GRPCClient/internal_testing/GRPCCall+Tests.h

@@ -45,6 +45,9 @@
  *
  * Must be called before any gRPC call to that host is made. It's illegal to pass the same host to
  * more than one invocation of the methods of this category.
+ *
+ * This function is for internal testing of gRPC only. It is not part of gRPC's public interface.
+ * Do not use in production. To enable, set the preprocessor flag GRPC_TEST_OBJC.
  */
 + (void)useTestCertsPath:(NSString *)certsPath
                 testName:(NSString *)testName
@@ -55,12 +58,18 @@
  *
  * Must be called before any gRPC call to that host is made. It's illegal to pass the same host to
  * more than one invocation of the methods of this category.
+ *
+ * This function is for internal testing of gRPC only. It is not part of gRPC's public interface.
+ * Do not use in production. To enable, set the preprocessor flag GRPC_TEST_OBJC.
  */
 + (void)useInsecureConnectionsForHost:(NSString *)host;
 
 /**
  * Resets all host configurations to their default values, and flushes all connections from the
  * cache.
+ *
+ * This function is for internal testing of gRPC only. It is not part of gRPC's public interface.
+ * Do not use in production. To enable, set the preprocessor flag GRPC_TEST_OBJC.
  */
 + (void)resetHostSettings;
 

src/objective-c/GRPCClient/internal_testing/GRPCCall+Tests.m

@@ -41,6 +41,7 @@
 + (void)useTestCertsPath:(NSString *)certsPath
                 testName:(NSString *)testName
                  forHost:(NSString *)host {
+#ifdef GRPC_TEST_OBJC
   if (!host || !certsPath || !testName) {
     [NSException raise:NSInvalidArgumentException format:@"host, path and name must be provided."];
   }
@@ -55,15 +56,32 @@
   GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
   [hostConfig setTLSPEMRootCerts:certs withPrivateKey:nil withCertChain:nil error:nil];
   hostConfig.hostNameOverride = testName;
+#else
+  NSLog(@"This function is for internal testing of gRPC only. "
+        "It is not part of gRPC's public interface. Do not use in production. "
+        "To enable, set the preprocessor flag GRPC_TEST_OBJC.");
+#endif
 }
 
 + (void)useInsecureConnectionsForHost:(NSString *)host {
+#ifdef GRPC_TEST_OBJC
   GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
   hostConfig.secure = NO;
+#else
+  NSLog(@"This function is for internal testing of gRPC only. "
+        "It is not part of gRPC's public interface. Do not use in production. "
+        "To enable, set the preprocessor flag GRPC_TEST_OBJC.");
+#endif
 }
 
 + (void)resetHostSettings {
+#ifdef GRPC_TEST_OBJC
   [GRPCHost resetAllHostSettings];
+#else
+  NSLog(@"This function is for internal testing of gRPC only. "
+        "It is not part of gRPC's public interface. Do not use in production. "
+        "To enable, set the preprocessor flag GRPC_TEST_OBJC.");
+#endif
 }
 
 + (void)enableOpBatchLog:(BOOL)enabled {