Disallow started request writers on GRPCCall init
diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index 279ef93..687932c 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -100,7 +100,9 @@
if (!host || !method) {
[NSException raise:NSInvalidArgumentException format:@"Neither host nor method can be nil."];
}
- // TODO(jcanizales): Throw if the requestWriter was already started.
+ if (requestWriter.state != GRXWriterStateNotStarted) {
+ [NSException raise:NSInvalidArgumentException format:@"The requests writer can't be already started."];
+ }
if ((self = [super init])) {
static dispatch_once_t initialization;
dispatch_once(&initialization, ^{