1 files changed, 38 insertions, 0 deletions
diff --git a/Functions/FirebaseFunctions/FUNUsageValidation.h b/Functions/FirebaseFunctions/FUNUsageValidation.h
new file mode 100644
index 0000000..17b1c4f
--- /dev/null
+++ b/Functions/FirebaseFunctions/FUNUsageValidation.h
@@ -0,0 +1,38 @@
+// Copyright 2017 Google
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** Helper for creating a general exception for invalid usage of an API. */
+NSException *FUNInvalidUsage(NSString *exceptionName, NSString *format, ...);
+
+/**
+ * Macro to throw exceptions in response to API usage errors. Avoids the lint warning you usually
+ * get when using @throw and (unlike a function) doesn't trigger warnings about not all codepaths
+ * returning a value.
+ *
+ * Exceptions should only be used for programmer errors made by consumers of the SDK, e.g.
+ * invalid method arguments.
+ *
+ * For recoverable runtime errors, use NSError**.
+ * For internal programming errors, use FSTFail().
+ */
+#define FUNThrowInvalidArgument(format, ...)                                       \
+  do {                                                                             \
+    @throw FUNInvalidUsage(@"FIRInvalidArgumentException", format, ##__VA_ARGS__); \
+  } while (0)
+
+NS_ASSUME_NONNULL_END