Make it possible to queue up diag for the context

fixes #1004

This adds a system for queuing diag messages that will be attached to
the next context that releases, upon release the diags will be issued so
long as the context caused at least 1 failure. The diags will be
disgarded if the context did not add any failures.

the `no_warnings` and `lives` tools both now automatically add the
warning/exception to the diag queue.

Examples:

This will add the warning as a diagnostics message
ok(no_warnings { warn "xxx" }, "Did not get any warnings");

This will not add the warning-diag as no failures are caused
ok(!no_warnings { warn "xxx" }, "Got warnings");

This will add the exception as a diagnostics message
ok(lives { die "XXX" }, "Did not die");

This will not add the exception as a diagnostics message
ok(!lives { die "XXX" }, "Died");

lib/Test2/API.pm

@@ -175,9 +175,19 @@ our @EXPORT_OK = qw{
     test2_enable_trace_stamps
     test2_disable_trace_stamps
     test2_trace_stamps_enabled
+
+    test2_add_pending_diag
+    test2_get_pending_diags
+    test2_clear_pending_diags
 };
 BEGIN { require Exporter; our @ISA = qw(Exporter) }
 
+my @PENDING_DIAGS;
+
+sub test2_add_pending_diag { push @PENDING_DIAGS => @_ }
+sub test2_get_pending_diags { @PENDING_DIAGS }
+sub test2_clear_pending_diags { my @out = @PENDING_DIAGS; @PENDING_DIAGS = (); return @out }
+
 my $STACK       = $INST->stack;
 my $CONTEXTS    = $INST->contexts;
 my $INIT_CBS    = $INST->context_init_callbacks;
@@ -445,6 +455,7 @@ sub context {
             eval_error  => $eval_error,
             child_error => $child_error,
             _is_spawn   => [$pkg, $file, $line, $sub],
+            _start_fail_count => $hub->{failed} // 0,
         },
         'Test2::API::Context'
     ) if $current && $depth_ok;
@@ -493,15 +504,16 @@ sub context {
     my $aborted = 0;
     $current = bless(
         {
-            _aborted     => \$aborted,
-            stack        => $stack,
-            hub          => $hub,
-            trace        => $trace,
-            _is_canon    => 1,
-            _depth       => $depth,
-            errno        => $errno,
-            eval_error   => $eval_error,
-            child_error  => $child_error,
+            _aborted          => \$aborted,
+            stack             => $stack,
+            hub               => $hub,
+            trace             => $trace,
+            _is_canon         => 1,
+            _depth            => $depth,
+            errno             => $errno,
+            eval_error        => $eval_error,
+            child_error       => $child_error,
+            _start_fail_count => $hub->{failed} // 0,
             $params{on_release} ? (_on_release => [$params{on_release}]) : (),
         },
         'Test2::API::Context'

lib/Test2/API/Context.pm

@@ -25,7 +25,7 @@ my %LOADED = (
 use Test2::Util::ExternalMeta qw/meta get_meta set_meta delete_meta/;
 use Test2::Util::HashBase qw{
     stack hub trace _on_release _depth _is_canon _is_spawn _aborted
-    errno eval_error child_error thrown
+    errno eval_error child_error thrown _failed _start_fail_count
 };
 
 # Private, not package vars
@@ -42,6 +42,8 @@ sub init {
     confess "The 'hub' attribute is required"
         unless $self->{+HUB};
 
+    $self->{+_START_FAIL_COUNT} = $self->{+HUB}->{failed} // 0;
+
     $self->{+_DEPTH} = 0 unless defined $self->{+_DEPTH};
 
     $self->{+ERRNO}       = $! unless exists $self->{+ERRNO};
@@ -64,6 +66,8 @@ sub DESTROY {
     my $hub = $self->{+HUB};
     my $hid = $hub->{hid};
 
+    $self->{+_FAILED} = ($hub->{failed} // 0) - $self->{+_START_FAIL_COUNT};
+
     # Do not show the warning if it looks like an exception has been thrown, or
     # if the context is not local to this process or thread.
     {
@@ -111,6 +115,12 @@ Cleaning up the CONTEXT stack...
         $_->($self) for reverse @$hcbk;
     }
     $_->($self) for reverse @$ON_RELEASE;
+
+    if (my @diags = Test2::API::test2_clear_pending_diags()) {
+        if ($self->{+_FAILED} || ${$self->{+_ABORTED}}) {
+            $self->diag($_) for @diags;
+        }
+    }
 }
 
 # release exists to implement behaviors like die-on-fail. In die-on-fail you
@@ -131,6 +141,8 @@ sub release {
     my $hub = $self->{+HUB};
     my $hid = $hub->{hid};
 
+    $self->{+_FAILED} = ($hub->{failed} // 0) - $self->{+_START_FAIL_COUNT};
+
     croak "context thinks it is canon, but it is not"
         unless $CONTEXTS->{$hid} && $CONTEXTS->{$hid} == $self;
 
@@ -146,6 +158,12 @@ sub release {
     }
     $_->($self) for reverse @$ON_RELEASE;
 
+    if (my @diags = Test2::API::test2_clear_pending_diags()) {
+        if ($self->{+_FAILED} || ${$self->{+_ABORTED}}) {
+            $self->diag($_) for @diags;
+        }
+    }
+
     # Do this last so that nothing else changes them.
     # If one of the hooks dies then these do not get restored, this is
     # intentional

lib/Test2/Tools/Exception.pm

@@ -5,7 +5,7 @@ use warnings;
 our $VERSION = '1.302204';
 
 use Carp qw/carp/;
-use Test2::API qw/context/;
+use Test2::API qw/context test2_add_pending_diag test2_clear_pending_diags/;
 
 our @EXPORT = qw/dies lives try_ok/;
 use base 'Exporter';
@@ -42,6 +42,8 @@ sub lives(&) {
         $err = $@;
     }
 
+    test2_add_pending_diag("Exception: $err");
+
     # If the eval failed we want to set $@ to the error.
     $@ = $err;
     return 0;
@@ -53,12 +55,13 @@ sub try_ok(&;$) {
     my $ok = &lives($code);
     my $err = $@;
 
+    my @diag = test2_clear_pending_diags();
+
     # Context should be obtained AFTER code is run so that events inside the
     # codeblock report inside the codeblock itself. This will also preserve $@
     # as thrown inside the codeblock.
     my $ctx = context();
-    chomp(my $diag = "Exception: $err");
-    $ctx->ok($ok, $name, [$diag]);
+    $ctx->ok($ok, $name, \@diag);
     $ctx->release;
 
     $@ = $err unless $ok;

lib/Test2/Tools/Warnings.pm

@@ -4,7 +4,7 @@ use warnings;
 
 our $VERSION = '1.302204';
 
-use Test2::API qw/context/;
+use Test2::API qw/context test2_add_pending_diag/;
 
 our @EXPORT = qw/warns warning warnings no_warnings/;
 use base 'Exporter';
@@ -17,7 +17,14 @@ sub warns(&) {
     return $warnings;
 }
 
-sub no_warnings(&) { return !&warns(@_) }
+sub no_warnings(&) {
+    my $warnings = &warnings(@_);
+    return 1 if !@$warnings;
+
+    test2_add_pending_diag(@$warnings);
+
+    return 0;
+}
 
 sub warning(&) {
     my $code = shift;

t/modules/Tools/Warnings.t

@@ -11,7 +11,22 @@ is(warns { warn 'a' }, 1, "1 warning");
 is(warns { warn 'a' for 1 .. 4 }, 4, "4 warnings");
 
 ok(no_warnings { 0 }, "no warnings");
-ok(!no_warnings { warn 'a' }, "warnings");
+
+ok(!no_warnings { warn 'blah 1' }, "warnings");
+
+my $es = intercept {
+    ok(!no_warnings { warn "blah 2\n" }, "warnings 1");
+    ok(no_warnings { warn "blah 3\n" }, "warnings 2")
+};
+
+like(
+    [grep { $_->isa('Test2::Event::Diag') } @$es],
+    [
+        {message => qr/Failed test 'warnings 2'/},
+        {message => "blah 3\n"},
+    ],
+    "When the test failed we got a diag about the warning, but we got no diag when it passed"
+);
 
 is(
     warnings { 0 },