Merge pull request #570 from dumarchie/master

Spectest for rakudo/rakudo#3137

S17-promise/single-assignment.t

@@ -0,0 +1,51 @@
+use v6;
+use Test;
+plan 12;
+
+my $exception = ::('X::Promise::Resolved');
+
+{
+    my $promise = Promise.new;
+    my $vow = $promise.vow;
+
+    $vow.keep(1);
+    is $promise.status, Kept, 'Keeping a vow keeps the promise';
+    is $promise.result, 1, 'Keeping a vow assigns a result to the promise';
+
+    throws-like { $vow.keep(2) }, $exception, promise => $promise,
+     message => 'Cannot keep/break a Promise more than once (status: Kept)',
+     'Keeping a vow throws if the promise was Kept already';
+
+    is $promise.result, 1,
+     'Keeping a vow does not change the result of an already Kept promise';
+
+    throws-like { $vow.break(3) }, $exception, promise => $promise,
+     message => 'Cannot keep/break a Promise more than once (status: Kept)',
+     'Breaking a vow throws if the promise was Kept already';
+
+    is $promise.status, Kept,
+     'Breaking a vow does not change the status of an already Kept promise';
+}
+
+{
+    my $promise = Promise.new;
+    my $vow = $promise.vow;
+
+    $vow.break(1);
+    is $promise.status, Broken, 'Breaking a vow breaks the promise';
+    is $promise.cause, 1, 'Breaking a vow assigns a cause to the promise';
+
+    throws-like { $vow.break(2) }, $exception, promise => $promise,
+     message => 'Cannot keep/break a Promise more than once (status: Broken)',
+     'Breaking a vow throws if the promise was Broken already';
+
+    is $promise.cause, 1,
+     'Breaking a vow does not change the cause of an already Broken promise';
+
+    throws-like { $vow.keep(3) }, $exception, promise => $promise,
+     message => 'Cannot keep/break a Promise more than once (status: Broken)',
+     'Keeping a vow throws if the promise was Broken already';
+
+    is $promise.status, Broken,
+     'Keeping a vow does not change the status of an already Broken promise';
+}

spectest.data

@@ -876,6 +876,7 @@ S17-promise/in.t         # slow
 S17-promise/lock-async.t
 S17-promise/lock-async-stress.t # moar stress slow
 S17-promise/lock-async-stress2.t # moar stress slow
+S17-promise/single-assignment.t
 S17-promise/start.t      # slow
 S17-promise/stress.t     # stress
 S17-promise/then.t