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|
use strict;
use warnings;
use base 'Exporter';
my @IMPORT;
BEGIN {
@IMPORT = qw(
strict
warnings
Test::More
Test::Exception
Test::Deep
JSON::MaybeXS
);
do { eval "use $_; 1" or die $@ } for @IMPORT;
}
use Data::Dumper;
our @EXPORT = qw(
run_test fake_promise_code promise_test
);
sub import {
my $target = caller;
$target->export_to_level(1);
$_->import::into(1) for @IMPORT;
}
sub run_test {
my ($args, $expected, $force_promise) = @_;
local $Test::Builder::Level = $Test::Builder::Level + 1;
my @args = @$args;
$args[7] ||= fake_promise_code() if !defined $force_promise or $force_promise;
my $got = execute(@args);
if (!defined $force_promise) {
if (ref $got eq 'FakePromise') {
$got = eval { $got->get };
is $@, '' or diag(explain $@), return;
}
} elsif ($force_promise) {
isa_ok $got, 'FakePromise' or diag(explain $got), return;
$got = eval { $got->get };
is $@, '' or diag(explain $@), return;
} else {
# specified did not want promise
isnt ref($got), 'FakePromise' or return;
}
cmp_deeply $got, $expected or diag explain $got;
}
sub promise_test {
my ($p, $fulfilled, $rejected) = @_;
local $Test::Builder::Level = $Test::Builder::Level + 1;
my $got = [ eval { $p->get } ];
is_deeply $got, $fulfilled or diag 'got unexpected result: ', explain $got;
my $e = $@;
is $e, $rejected or diag 'got unexpected error: ', explain $e;
}
sub fake_promise_code {
+{
resolve => FakePromise->curry::resolve,
reject => FakePromise->curry::reject,
all => FakePromise->curry::all,
new => FakePromise->curry::new,
};
}
sub fake_promise_iterator {
require GraphQL::AsyncIterator;
GraphQL::AsyncIterator->new(
promise_code => fake_promise_code(),
);
}
{
package FakePromise;
use Moo;
use GraphQL::PubSub;
use curry;
has status => (is => 'rw'); # status = undef/'fulfilled'/'rejected'
has _values => (is => 'rw');
has parent => (is => 'ro');
has handlers => (is => 'ro');
has pubsub => (is => 'lazy', builder => sub { GraphQL::PubSub->new });
sub BUILD {
my ($self, $args) = @_;
if (my $parent = $args->{parent}) {
$self->_get_or_subscribe($parent, $self->curry::settle);
}
}
sub _get_or_subscribe {
my ($self, $promise, $func) = @_;
if (defined(my $status = $promise->status)) {
# parent settled, copy now
$func->($status, @{$promise->_values});
} else {
$promise->pubsub->subscribe(settle => $func);
}
}
sub resolve {
my $self = shift;
$self = $self->new if !ref $self;
$self->settle('fulfilled', @_);
$self;
}
sub reject {
my $self = shift;
$self = $self->new if !ref $self;
$self->settle('rejected', @_);
$self;
}
sub all {
my $self = shift;
die "all is a class method only" if ref $self;
$self = $self->new;
my ($i, @values) = (0);
my $unsettled = grep ref($_) eq __PACKAGE__, @_;
my @promise_deferral; # till after @values filled, avoid prematurely settle
for my $v (@_) {
if (ref(my $promise = $v) eq __PACKAGE__) {
my $this_value_index = $i;
push @values, undef;
push @promise_deferral, [ $promise, sub {
my ($status, @these_vals) = @_;
if ($status eq 'rejected') {
$self->settle($status, @these_vals);
} elsif (!defined $self->status) {
# if it IS defined, we already got rejected so it's over
$values[$this_value_index] = \@these_vals;
$unsettled--;
if ($unsettled <= 0) {
$self->settle('fulfilled', @values);
}
}
} ];
} else {
push @values, [ $v ];
}
$i++;
}
$self->_get_or_subscribe(@$_) for @promise_deferral;
$self;
}
sub then {
my $self = shift;
$self->new(parent => $self, handlers => +{ then => shift, catch => shift });
}
sub catch { shift->then(undef, @_) }
sub _safe_call {
my @r = eval { $_[0]->() };
$@ ? ('rejected', $@) : ('fulfilled', @r);
}
sub _settled_with_promise {
my ($self, $value) = @_;
return 0 if ref($value) ne __PACKAGE__;
$self->_get_or_subscribe($value, $self->curry::settle);
1;
}
sub settle {
my $self = shift;
die "Error: tried to settle an already-settled promise"
if defined $self->status;
my ($status, @values) = @_;
return if $self->_settled_with_promise($values[0]);
if (my $h = delete $self->{handlers}) {
# zap as no longer needed, might get rerun if was settled with promise
if ($status eq 'fulfilled' and $h->{then}) {
($status, @values) = _safe_call(sub { $h->{then}->(@values) });
return if $self->_settled_with_promise($values[0]);
}
if ($status eq 'rejected' and $h->{catch}) {
($status, @values) = _safe_call(sub { $h->{catch}->(@values) });
return if $self->_settled_with_promise($values[0]);
}
}
$self->status($status);
$self->_values(\@values);
$self->pubsub->publish(settle => $status, @values) if $self->{pubsub};
}
sub get {
my $self = shift;
die "Error: tried to 'get' a non-settled promise"
if !defined $self->status;
my @values = @{$self->_values};
die @values if $self->status eq 'rejected';
die "Tried to scalar-get but >1 value" if !wantarray and @values > 1;
return $values[0] if !wantarray;
@values;
}
}
1;
|
