This commit adds robust input validation to the SetGasPrice method and
implements comprehensive table-driven tests to ensure correct behavior.
Changes in core/txpool/txpool.go:
- Add nil gas price validation with graceful error handling
- Add validation to reject negative gas prices
- Add validation to reject gas prices exceeding 1000 GWei maximum
- Return detailed error messages for each validation failure
- Log warnings when invalid gas prices are rejected
Changes in eth/api_miner.go:
- Update MinerAPI.SetGasPrice to check error return from txPool.SetGasPrice
- Return false when validation fails (when SetGasPrice returns error)
- Return true when validation succeeds (when SetGasPrice returns nil)
New tests in core/txpool/txpool_test.go:
- Implement TestSetGasPrice using table-driven test pattern
- Test 4 invalid cases: nil, negative, exceed max+1, exceed 10000 GWei
- Test 7 valid cases: 0, 1 wei, 1 GWei, 100 GWei, 500 GWei, max-1, max
- Each test case includes expected error value for precise validation
- All 11 test cases verify both error returns and gas price state
- Tests use isolated pool instances to ensure independence
