When I began quilting in the late 80's I was taught how to check a fabric to see if it would bleed. Take a piece of white muslin and wet a small area of the fabric in question, rub/scrub the muslin over the wet area. IF you have color on the muslin take the fabric and wash/iron it.
But another method that was taught in the early 90's was to steam press the fabric with a hot iron to set the color. The steam and heat represent washing and drying, and you should notice any shrinkage at that time. I still use this method.