How to test a smart contract without risking real bitcoin?

In the realm of cryptocurrency and decentralized finance, testing smart contracts is crucial to ensure their reliability and security before deployment. However, the question arises: how can one effectively test these complex digital agreements without incurring the risk of utilizing real bitcoin? Given the volatile nature of cryptocurrencies and the potential for significant financial losses, it is imperative to devise testing methodologies that minimize this risk. What strategies and tools are available to simulate contract execution and identify potential vulnerabilities without investing actual bitcoins? Additionally, how can one ensure that the testing environment accurately reflects the real-world conditions and dynamics of the blockchain? This is a pertinent inquiry that seeks to balance the need for rigorous testing with the imperative to safeguard financial assets.