f - expand test coverage

Author: jkczyz

lightning/src/ln/features.rs

@@ -952,25 +952,36 @@ mod tests {
 		features1.set_gossip_queries_optional();
 		features1.set_variable_length_onion_optional();
 		features1.set_payment_secret_optional();
+		features1.set_basic_mpp_optional();
+		assert_eq!(features1.flags.len(), 3);
 		assert_eq!(features1.flags[0], 0b10000110);
 		assert_eq!(features1.flags[1], 0b10000010);
+		assert_eq!(features1.flags[2], 0b00000010);
 
 		let mut features2 = InitFeatures::empty();
 		features2.set_data_loss_protect_optional();
 		features2.set_upfront_shutdown_script_optional();
 		features2.set_gossip_queries_optional();
 		features2.set_variable_length_onion_optional();
 		features2.set_static_remote_key_optional();
+		features2.set_basic_mpp_optional();
+		assert_eq!(features2.flags.len(), 3);
 		assert_eq!(features2.flags[0], 0b10100010);
 		assert_eq!(features2.flags[1], 0b00100010);
+		assert_eq!(features1.flags[2], 0b00000010);
 
 		let features1_minus2 = features1.clone() - features2.clone();
+		assert_eq!(features1_minus2.flags.len(), 2);
 		assert_eq!(features1_minus2.flags[0], 0b00000100);
 		assert_eq!(features1_minus2.flags[1], 0b10000000);
 
-		let features2_minus1 = features2 - features1;
+		let features2_minus1 = features2 - features1.clone();
+		assert_eq!(features2_minus1.flags.len(), 2);
 		assert_eq!(features2_minus1.flags[0], 0b00100000);
 		assert_eq!(features2_minus1.flags[1], 0b00100000);
+
+		let empty_features = features1.clone() - features1;
+		assert!(empty_features.flags.is_empty());
 	}
 
 	#[test]