The idiom 'to put someone to the test' means to push someone to the limits of their ability or intellect in order to discover how able or capable they are to deal with a particular circumstance or situation. Sometimes you might 'put something or someone to the test' in order to trial something or to see if it can perform as needed.

1. We've had a couple of easy matches so far, but I expect our next opponents will put us to the test.
2. I have a good feeling that my idea will work, but I'll have to put it to the test.

1. The sales pitch will be a big challenge for me. My public speaking skills are really going to be put to the test!
2. Giving Claire full control over the marketing campaign is the best way of putting her ideas to the test.
3. The scientist wanted to put his theory to the test, so he devised and carried out a series of experiments.