NAME

Selkie::Test::Tree - Find and assert on widgets inside a built tree

SYNOPSIS

use Test;
use Selkie::Test::Tree;
use Selkie::Widget::Button;

# $root is some layout tree built by your app code
my $save-btn = find-widget $root, -> $w {
    $w ~~ Selkie::Widget::Button && $w.label eq 'Save';
};
ok $save-btn.defined, 'Save button exists';

my @all-buttons = find-widgets $root, -> $w { $w ~~ Selkie::Widget::Button };
is @all-buttons.elems, 3, 'three buttons total';

contains-widget-ok $root, $save-btn, 'save button reachable from root';

done-testing;

DESCRIPTION

When a widget tree is built by a subscription callback or a factory helper, you often don't hold direct references to every child. These helpers walk the tree (descending through Container children and Border/Modal content) so tests can locate widgets by predicate.

The walk function is the underlying iterator; the other helpers build on it. Write find-widget($root, &pred) for "first match" and find-widgets($root, &pred) for "all matches". The predicate is any Callable that takes a widget and returns a truthy value.

EXAMPLES

Find by widget type

my $first-input = find-widget $root,
    -> $w { $w ~~ Selkie::Widget::TextInput };

Find by attribute

my $title-bar = find-widget $root, -> $w {
    $w ~~ Selkie::Widget::Text && $w.text.starts-with('Settings');
};

Assert the tree's shape

is find-widgets($root, * ~~ Selkie::Widget::Button).elems, 2, 'two buttons';
is find-widgets($root, * ~~ Selkie::Widget::ListView).elems, 1, 'one list';

Verify a widget is still reachable

Useful to catch regressions where a widget gets destroyed but tests still held a reference:

contains-widget-ok $root, $my-input, 'input still in the tree';

SEE ALSO

• Selkie::Container — provides the children list walk descends through

• Selkie::Widget::Border, Selkie::Widget::Modal — walked through their content

sub walk

sub walk(
    Selkie::Widget $root
) returns Seq

Iterate every widget reachable from $root, depth-first. Yields $root itself first, then descends through Container.children and any .content (for Border/Modal). Lazy — safe to short-circuit with .first.

sub find-widget

sub find-widget(
    Selkie::Widget $root,
    &predicate
) returns Selkie::Widget

Return the first widget matching the predicate, or Nil. The predicate can be any Callable taking a widget; smartmatch also works thanks to Raku's * whatever star: find-widget root, -> w.focusable };

sub find-widgets

sub find-widgets(
    Selkie::Widget $root,
    &predicate
) returns List

Return every widget in the tree matching the predicate, in walk order.

sub contains-widget-ok

sub contains-widget-ok(
    Selkie::Widget $root,
    Selkie::Widget $target,
    Str:D $desc
) returns Mu

Test assertion: $target is reachable from $root. Uses identity comparison (===), so it's checking the same widget instance.