1IO::Async::Test(3)    User Contributed Perl Documentation   IO::Async::Test(3)
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NAME

6       "IO::Async::Test" - utility functions for use in test scripts
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SYNOPSIS

9        use Test::More tests => 1;
10        use IO::Async::Test;
11
12        use IO::Async::Loop;
13        my $loop = IO::Async::Loop->new();
14        testing_loop( $loop );
15
16        my $result;
17
18        $loop->do_something(
19           some => args,
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21           on_done => sub {
22              $result = the_outcome;
23           }
24        );
25
26        wait_for { defined $result };
27
28        is( $result, what_we_expected, 'The event happened' );
29
30        ...
31
32        my $buffer = "";
33        my $handle = IO::Handle-> ...
34
35        wait_for_stream { length $buffer >= 10 } $handle => $buffer;
36
37        is( substr( $buffer, 0, 10, "" ), "0123456789", 'Buffer was correct' );
38

DESCRIPTION

40       This module provides utility functions that may be useful when writing
41       test scripts for code which uses "IO::Async" (as well as being used in
42       the "IO::Async" test scripts themselves).
43
44       Test scripts are often synchronous by nature; they are a linear
45       sequence of actions to perform, interspersed with assertions which
46       check for given conditions. This goes against the very nature of
47       "IO::Async" which, being an asynchronisation framework, does not
48       provide a linear stepped way of working.
49
50       In order to write a test, the "wait_for()" function provides a way of
51       synchronising the code, so that a given condition is known to hold,
52       which would typically signify that some event has occured, the outcome
53       of which can now be tested using the usual testing primitives.
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55       Because the primary purpose of "IO::Async" is to provide IO operations
56       on filehandles, a great many tests will likely be based around
57       connected pipes or socket handles. The "wait_for_stream()" function
58       provides a convenient way to wait for some content to be written
59       through such a connected stream.
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FUNCTIONS

62   testing_loop( $loop )
63       Set the "IO::Async::Loop" object which the "wait_for()" function will
64       loop on.
65
66   wait_for( $condfunc )
67       Repeatedly call the "loop_once()" method on the underlying loop (given
68       to the "testing_loop()" function), until the given condition function
69       callback returns true.
70
71       To guard against stalled scripts, if the loop indicates a timeout for
72       10 consequentive seconds, then an error is thrown.
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74   wait_for_stream( $condfunc, $handle, $buffer )
75       Set up an "IO::Async::Stream" object around the given $handle. Data
76       read from the stream will be appended into $buffer (which is NOT
77       initialised when the function is entered, in case data remains from a
78       previous call). The "loop_once" method is then repeatedly called until
79       the condition function callback returns true. After this, the temporary
80       stream will be removed from the loop.
81

AUTHOR

83       Paul Evans <leonerd@leonerd.org.uk>
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87perl v5.12.1                      2010-06-09                IO::Async::Test(3)
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