Selkie.git | t/ | 74-split-extreme-sizes.rakutest

---

use Test;
use lib 'lib';

use Selkie::Layout::Split;
use Selkie::Sizing;

# The boundary math in Selkie::Layout::Split must not underflow when
# the parent axis is squeezed to 0 or 1 cells. Pre-fix, the
# UInt-typed `$total - $first-w - 1` was assigned before the `max 0`
# clamp ran, so a tmux pane resize to 1 cell threw X::TypeCheck::
# Assignment out of render() and killed the whole TUI frame.

plan 8;

sub mk-split($ratio, $orientation = 'horizontal') {
    Selkie::Layout::Split.new(
        :$orientation,
        :$ratio,
        sizing => Sizing.flex,
    );
}

subtest "1-cell axis with ratio 0.5 — no underflow" => {
    plan 3;
    my %s = mk-split(0.5).compute-split-sizes(1, 0.5);
    is %s<first>, 1, "first clamped to 1 (the whole axis)";
    is %s<divider>, 1, "divider lands at the end";
    is %s<second>, 0, "second collapsed to 0 — no room";
};

subtest "1-cell axis with ratio 0.9 — no underflow" => {
    plan 3;
    my %s = mk-split(0.9).compute-split-sizes(1, 0.9);
    is %s<first>, 1, "first clamped to 1";
    is %s<divider>, 1, "divider at end";
    is %s<second>, 0, "second collapsed";
};

subtest "2-cell axis — first + divider, no room for second" => {
    plan 3;
    my %s = mk-split(0.5).compute-split-sizes(2, 0.5);
    is %s<first>, 1, "first gets 1 cell";
    is %s<divider>, 1, "divider at column 1";
    is %s<second>, 0, "second still has no room (2 - 1 - 1 = 0)";
};

subtest "3-cell axis — first + divider + second" => {
    plan 3;
    my %s = mk-split(0.5).compute-split-sizes(3, 0.5);
    is %s<first>, 1, "first gets floor(1.5) = 1";
    is %s<divider>, 1, "divider at column 1";
    is %s<second>, 1, "second gets 1";
};

subtest "0-cell axis — every slot zero, no crash" => {
    plan 3;
    my %s = mk-split(0.5).compute-split-sizes(0, 0.5);
    is %s<first>, 0, "first is 0";
    is %s<divider>, 0, "divider is 0";
    is %s<second>, 0, "second is 0";
};

subtest "extreme ratio 0.99 on 100 cells" => {
    plan 3;
    my %s = mk-split(0.99).compute-split-sizes(100, 0.99);
    is %s<first>, 99, "first ≈ ratio × total";
    is %s<divider>, 99, "divider at 99";
    is %s<second>, 0, "second = 100 - 99 - 1 = 0";
};

subtest "extreme ratio 0.01 on 100 cells — first clamped to >=1" => {
    plan 3;
    my %s = mk-split(0.01).compute-split-sizes(100, 0.01);
    is %s<first>, 1, "first clamped up from floor(1.0) = 1 (min)";
    is %s<divider>, 1, "divider at 1";
    is %s<second>, 98, "second gets the rest";
};

subtest "construction with edge ratios doesn't crash" => {
    plan 3;
    lives-ok { mk-split(0.0) },  "ratio 0.0 constructs";
    lives-ok { mk-split(1.0) },  "ratio 1.0 constructs";
    lives-ok { mk-split(0.5, 'vertical') }, "vertical orientation constructs";
};