Wiktionary
sniff test
n. (context idiomatic English) An informal reality check of an idea or proposal, using one's common sense or sense of propriety.
Usage examples of "sniff test".
His sniff test revealed one lot that resembled coffee, another that might have been beer, and one that was probably water.
He had successfully carried out his first burglary, and he had passed his sniff test, and he had just heard and spoken two of his very favorite cliché.