IO::Async::Test(3pm) User Contributed Perl Documentation IO::Async::Test(3pm)
NAME
"IO::Async::Test" - utility functions for use in test scripts
SYNOPSIS
use Test::More tests => 1;
use IO::Async::Test;
use IO::Async::Loop;
my $loop = IO::Async::Loop->new;
testing_loop( $loop );
my $result;
$loop->do_something(
some => args,
on_done => sub {
$result = the_outcome;
}
);
wait_for { defined $result };
is( $result, what_we_expected, 'The event happened' );
...
my $buffer = "";
my $handle = IO::Handle-> ...
wait_for_stream { length $buffer >= 10 } $handle => $buffer;
is( substr( $buffer, 0, 10, "" ), "0123456789", 'Buffer was correct' );
my $result = wait_for_future( $stream->read_until( "\n" ) )->get;
DESCRIPTION
This module provides utility functions that may be useful when writing
test scripts for code which uses IO::Async (as well as being used in
the IO::Async test scripts themselves).
Test scripts are often synchronous by nature; they are a linear
sequence of actions to perform, interspersed with assertions which
check for given conditions. This goes against the very nature of
IO::Async which, being an asynchronisation framework, does not provide
a linear stepped way of working.
In order to write a test, the "wait_for" function provides a way of
synchronising the code, so that a given condition is known to hold,
which would typically signify that some event has occurred, the outcome
of which can now be tested using the usual testing primitives.
Because the primary purpose of IO::Async is to provide IO operations on
filehandles, a great many tests will likely be based around connected
pipes or socket handles. The "wait_for_stream" function provides a
convenient way to wait for some content to be written through such a
connected stream.
FUNCTIONS
testing_loop
testing_loop( $loop )
Set the IO::Async::Loop object which the "wait_for" function will loop
on.
wait_for
wait_for { COND } OPTS
Repeatedly call the "loop_once" method on the underlying loop (given to
the "testing_loop" function), until the given condition function
callback returns true.
To guard against stalled scripts, if the loop indicates a timeout for
(a default of) 10 consequentive seconds, then an error is thrown.
Takes the following named options:
timeout => NUM
The time in seconds to wait before giving up the test as being
stalled. Defaults to 10 seconds.
wait_for_stream
wait_for_stream { COND } $handle, $buffer
As "wait_for", but will also watch the given IO handle for readability,
and whenever it is readable will read bytes in from it into the given
buffer. The buffer is NOT initialised when the function is entered, in
case data remains from a previous call.
$buffer can also be a CODE reference, in which case it will be invoked
being passed data read from the handle, whenever it is readable.
wait_for_future
$future = wait_for_future $future
Since version 0.68.
A handy wrapper around using "wait_for" to wait for a Future to become
ready. The future instance itself is returned, allowing neater code.
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.34.0 2022-08-19 IO::Async::Test(3pm)
Generated by dwww version 1.15 on Wed Jun 26 18:06:35 CEST 2024.