solidity-testing

Language Rule

• Always respond in the same language the user is using. If the user asks in Chinese, respond in Chinese. If in English, respond in English.

Test Organization

• One test contract per source contract: MyToken.sol → MyToken.t.sol
• File location: All tests in test/ directory
• Naming: test_<feature>_<scenario> for passing tests, testFail_<feature>_<scenario> for expected reverts
  • Example: test_transfer_revertsWhenInsufficientBalance
  • Example: test_stake_updatesBalanceCorrectly
• Independence: Each test must run in isolation — use setUp() for shared state, no cross-test dependencies
• Filtering: Support --match-test and --match-contract for targeted runs

Coverage Requirements

Every core function must have tests covering:

| Scenario | What to verify | |----------|---------------| | Happy path | Standard input → expected output, correct state changes | | Permission checks | Unauthorized caller → vm.expectRevert with correct error | | Boundary conditions | Zero values, max values (type(uint256).max), off-by-one | | Failure scenarios | Every require / revert / custom error path | | State changes | Storage updates, balance changes, event emissions (vm.expectEmit) | | Edge cases | Empty arrays, duplicate calls, self-transfers |

Foundry Cheatcodes Quick Reference

| Cheatcode | Usage | |-----------|-------| | vm.prank(addr) | Next call from addr | | vm.startPrank(addr) | All calls from addr until vm.stopPrank() | | vm.warp(timestamp) | Set block.timestamp | | vm.roll(blockNum) | Set block.number | | vm.deal(addr, amount) | Set ETH balance | | vm.expectRevert(error) | Next call must revert with specific error | | vm.expectEmit(true,true,false,true) | Verify event emission (topic checks) | | vm.record() / vm.accesses() | Track storage reads/writes | | makeAddr("name") | Create labeled address for readable traces |

Fuzz Testing Rules

• All math-heavy and fund-flow functions must have fuzz tests
• Pattern: function testFuzz_<name>(uint256 amount) public
• Use vm.assume() to constrain inputs: vm.assume(amount > 0 && amount < MAX_SUPPLY);
• Default runs: 256 — increase to 10,000+ for critical functions: forge test --fuzz-runs 10000

Common Commands

# Run all tests
forge test

# Run specific test function
forge test --match-test test_transfer

# Run specific test contract
forge test --match-contract MyTokenTest

# Verbose output with full trace
forge test -vvvv

# Gas report
forge test --gas-report

# Fuzz with more runs
forge test --fuzz-runs 10000

# Test coverage
forge coverage

# Coverage with report
forge coverage --report lcov