CleanupPath detects the existence of test DB file and removes it if found.

PathOfTempFile returns path of a new temporary file.

RandomPort returns a random port number between 30000 and 50000.

SignalChan returns a channel that will be written every interval until timeout.

TimestampNow returns current time from new clock.

WaitUntil periodically checks whether the condition specified in CheckCondition function is satisfied If an error is returned, it either comes from CheckCondition function or time is up before the given condition is satisfied.

TestGasLimit represents the gas limit used for test actions.

TestGasPriceInt64 represents the gas price for test actions in int64.

ErrTimeout is returned when time is up.

TestGasPrice represents the gas price for test actions in big int.

CheckCondition defines a func type that checks whether a certain condition is satisfied.