This may sound crazy, but it's how I've done it for years.
I call this the towel and cell phone method. Once I've completed sweating the joints, I spread a couple of old bath towels around to catch any drips or spray if the joint leaks. Next, I hand my wife a flash light and make sure she has her phone ready. I walk out front to the water meter and call her with my phone, put it on speaker and set it in the grass by the meter. I turn the water back on and if she sees a leak, she yells and I turn the water off and re-do my joint.
Works for me.
BTW, watch 1/2 dozen YouTube videos and you should learn about all the tricks you need to sweat pipes the first time without leaks.
One trick I learned from a plumber is to have your shop vac handy and in "wet" mode (ie. no filter). Once you cut the existing pipe, turn on the vac and suction the pipe to remove as much water as it will. Cup your hand around the pipe for a better seal. I've heard it will remove several feet of water (pipe length) and form a vacuum lock on the water supply up in the pipe. Getting the water away from the sweat point will make soldering possible where it ordinarily would not be.