Struct Mock 

pub struct Mock { /* private fields */ }

Available on crate feature mock only.

A mock backend for use in testing.

By default, the backend discards all data written to it without any validation. However, the Mock::set_write_callback can be used to change this behaviour and to dynamically generate custom responses from devices. Alternatively, responses can be emulated by manually adding their raw bytes via Mock::push.

To test behaviour in the face of errors, there are dedicated methods for defining errors the mock will return.

Implementations

impl Mock

pub fn push<T: AsRef<[u8]>>(&mut self, bytes: T)

Available on crate features mock only.

Push data to the read buffer.

The data is not validated in any way.

pub fn clear(&mut self)

Available on crate features mock only.

Clear the read buffer.

pub fn is_empty(&self) -> bool

Available on crate features mock only.

Whether the mock has any data available or not.

pub fn set_read_error(&mut self, err: Option<Error>)

Available on crate features mock only.

Set the error to be returned when Mock::read is next called, if any.

The error is returned only once.

pub fn set_write_error(&mut self, err: Option<Error>)

Available on crate features mock only.

Set the error to be returned when Mock::write is next called, if any.

The error is returned only once.

pub fn set_flush_error(&mut self, err: Option<Error>)

Available on crate features mock only.

Set the error to be returned when Mock::flush is next called, if any.

The error is returned only once.

pub fn set_read_timeout_error(&mut self, err: Option<Error>)

Available on crate features mock only.

Set the error to be returned when Mock::set_read_timeout is next called, if any.

The error is returned only once.

pub fn set_write_callback( &mut self, callback: impl FnMut(&[u8], &mut dyn Write) + 'static, )

Available on crate features mock only.

Set the function to call when bytes are written to the backend.

The callback is passed two arguments: a reference to the written bytes and a mutable reference to the mock’s read buffer. Any emulated responses to the command’s bytes should be written to the read buffer.

By default, the Mock ignores all data written to it.

Example

let mut port = Port::open_mock();
port.backend_mut().set_write_callback(|message, reply_buffer| {
    match message {
        b"/1 io get ai 1\n" => write!(reply_buffer, "@01 0 OK BUSY -- 5.5\r\n"),
        b"/get pos\n" => write!(reply_buffer, "@01 0 OK BUSY -- 20\r\n@02 0 OK BUSY -- 10.1\r\n"),
        _ => panic!("unexpected message"),
    }.unwrap()
});
let reply = port.command_reply((1,"io get ai 1"))?.flag_ok()?;
assert_eq!(reply.data().parse::<f64>().unwrap(), 5.5);

Trait Implementations

impl Backend for Mock

Available on crate features mock only.

fn set_read_timeout(&mut self, timeout: Option<Duration>) -> Result<(), Error>

Set the read timeout.

fn read_timeout(&self) -> Result<Option<Duration>, Error>

Get the read timeout.

fn name(&self) -> Option<String>

Get the “name” of the backend.

impl Debug for Mock

Available on crate features mock only.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Read for Mock

Available on crate features mock only.

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_, u8>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact( &mut self, cursor: BorrowedCursor<'_, u8>, ) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

fn read_array<const N: usize>(&mut self) -> Result<[u8; N], Error>

where Self: Sized,

🔬This is a nightly-only experimental API. (read_array)

Read and return a fixed array of bytes from this source.

fn read_le<T>(&mut self) -> Result<T, Error>

where T: FromEndianBytes, Self: Sized,

🔬This is a nightly-only experimental API. (read_le)

Read and return a type (e.g. an integer) in little-endian order.

fn read_be<T>(&mut self) -> Result<T, Error>

where T: FromEndianBytes, Self: Sized,

🔬This is a nightly-only experimental API. (read_le)

Read and return a type (e.g. an integer) in big-endian order.

impl Write for Mock

Available on crate features mock only.

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.