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use Test; | |
class Promise { | |
enum State <PENDING FULFILLED REJECTED>; | |
has State $.state = PENDING; | |
has @.on-fulfill; | |
has @.on-reject; | |
has $.value; | |
has $.reason; | |
method fulfill($value) { | |
return unless $!state == PENDING; | |
$!state = FULFILLED; | |
for @!on-fulfill -> &cb { | |
&cb($value) | |
} | |
} | |
method reject($reason) { | |
return unless $!state == PENDING; | |
$!state = REJECTED; | |
for @!on-reject -> &cb { | |
&cb($reason) | |
} | |
} | |
method then(&yep, &nope?) { | |
@!on-fulfill.push: &yep; | |
@!on-reject.push: &nope if &nope; | |
if $!state == FULFILLED { | |
&yep($!value) | |
} elsif $!state == REJECTED { | |
&nope($!reason) | |
} | |
return self | |
} | |
} | |
{ | |
my $promise = Promise.new; | |
my $value = 0; | |
$promise.then(sub ($arg) { $value = $arg }); | |
ok !$value, "Hasn't been fulfilled yet"; | |
$promise.fulfill("OH HAI"); | |
is $promise.state, Promise::State::FULFILLED, "Correct state"; | |
is $value, "OH HAI", "Code has been run"; | |
} | |
{ | |
my $promise = Promise.new(state => Promise::State::FULFILLED, | |
value => "yay!"); | |
is $promise.state, Promise::State::FULFILLED, "Already correct state"; | |
my $value = 0; | |
$promise.then({ $value = $^arg }); | |
is $value, "yay!", "Code ran immediately"; | |
} | |
{ | |
my $promise = Promise.new; | |
my $value = 0; | |
my $reason = 0; | |
$promise.then({ $value = $^arg }, { $reason = $^arg }); | |
ok !$reason, "Hasn't been rejected yet"; | |
$promise.reject("OH NOES"); | |
is $promise.state, Promise::State::REJECTED, "Correct state"; | |
ok !$value, "Fulfill code didn't run"; | |
is $reason, "OH NOES", "Reject code has been run"; | |
} | |
{ | |
my $promise = Promise.new; | |
my $value = 0; | |
$promise.then({ $value++ }); | |
$promise.then({ $value++ }); | |
$promise.then({ $value++ }); | |
ok !$value, "Hasn't been fulfilled yet"; | |
$promise.fulfill("OH HAI"); | |
is $promise.state, Promise::State::FULFILLED, "Correct state"; | |
is $value, 3, "Code has been run"; | |
} | |
done; |
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