kotlin.test / kotlin.test / Asserter / assertTrue assertTrue Common JVM JS Native 1.0 open fun assertTrue ( lazyMessage : ( ) -> String ? , actual : Boolean ) : Unit (source) Asserts that the specified value is true . Parameters lazyMessage - the function to return a message to report if the assertion fails. Common JVM JS Native 1.0 open fun assertTrue ( message : String ? , actual : Boolean ) : Unit (source) Asserts that the specified value is true . Parameters message - the message to report if the assertion fails.