Method expect_err

std/src/testutils.rs:889–892

Expects the invocation to have erroneously terminated with the exact `message`. If not called, defaults to expecting that execution terminated due to EOF. This or `expect_err` can only be called once.

(mut self, message: S)

    /// If not called, defaults to expecting that execution terminated due to EOF.  This or
    /// `expect_err` can only be called once.
    pub fn expect_err<S: Into<String>>(mut self, message: S) -> Self {
        self.exp_result = Err(message.into());
        self
    }

    /// Adds the `name` array as an array to expect in the final state of the machine.  The array
    /// will be tested to have the same `subtype` and `dimensions`, as well as specific `contents`.