Add comments to packet coalescing test
diff --git a/src/objective-c/tests/InteropTests.m b/src/objective-c/tests/InteropTests.m
index 4e5a528..c9941fd 100644
--- a/src/objective-c/tests/InteropTests.m
+++ b/src/objective-c/tests/InteropTests.m
@@ -164,11 +164,15 @@
expectedResponse.payload.body = [NSMutableData dataWithLength:10];
XCTAssertEqualObjects(response, expectedResponse);
+ // The test is a success if there is a batch of exactly 3 ops (SEND_INITIAL_METADATA,
+ // SEND_MESSAGE, SEND_CLOSE_FROM_CLIENT). Without packet coalescing each batch of ops contains
+ // only one op.
NSArray *opBatches = [GRPCCall obtainAndCleanOpBatchLog];
+ const NSInteger kExpectedOpBatchSize = 3;
for (NSObject *o in opBatches) {
if ([o isKindOfClass:[NSArray class]]) {
NSArray *batch = (NSArray *)o;
- if ([batch count] == 3) {
+ if ([batch count] == kExpectedOpBatchSize) {
[expectation fulfill];
break;
}