Testing Entry Points Locally — Forge College

Want fast, deterministic validation of your Solana program entry logic without deploying to a validator? Local tests let you exercise parsing, authorization, and state transitions in seconds instead of minutes. What you'll learn In this lesson you'll set up a local test harness and author both unit and integration-style tests that exercise your Rust entry point behavior. You will learn how to call the processor (entry) function directly with mocked AccountInfo, construct instruction_data byte slices, and assert ProgramResult outcomes. You will also configure solana-program-test to run the same instruction in a simulated runtime, inspect account data changes, and validate side effects across transactions. Practical patterns for test isolation, deterministic setup, and debugging failing tests (targeted assertions, logs, and account snapshots) are covered so your cargo test runs are fast and reproducible. Who this is for Intermediate Rust and Solana developers who already understand the entry function signature (program_id: &Pubkey, accounts: &[AccountInfo], instruction_data: &[u8]) and basic account model. Intended for developers ready to add robust unit and integration tests to their program workflow. Key topics covered - Setting up a local test harness and dev-dependencies (solana-program-test, solana-sdk) - Writing unit tests that call the processor with mocked AccountInfo and instruction bytes - Integration-style tests using solana-program-test to simulate runtime transactions - Asserting state changes, account data mutations, and returned errors (ProgramResult) - Test isolation patterns and deterministic setup for repeatable cargo test runs - Debugging techniques: logs, targeted assertions, and account snapshots Get started building reproducible tests and speed up your development loop: https://www.forge.college/