path: root/tests/test_split_ux.py

#!/usr/bin/env python3
"""Splitting by clicking a border, with a guide that shows what will happen.

The old per-pane `+` was one glyph for a verb that has four directions, and it
taxed every frame three columns forever. A border encodes the direction by
being on that side, costs nothing when idle, and shows a preview on hover.
"""

import os
import sys
import tempfile
import time

from harness import Session, check, report

FAST_TEXT = "hover_delay_ms 20\n"


def cfg(text):
    f = tempfile.NamedTemporaryFile("w", suffix=".kdl", delete=False)
    f.write(text)
    f.close()
    return f.name


FAST = cfg(FAST_TEXT)

SH = ["/bin/sh", "-c", 'printf "\\033]2;shell\\007"; stty raw -echo; cat']


def hover(s, x, y):
    s.send(rf"\e[<35;{x + 1};{y + 1}M")


def rest(s, x, y):
    """Hover and stay there: the guide arms on dwell, not on contact.

    The wait is real elapsed time - the guide is gated on a clock, not on
    anything observable - so the sessions that are not *about* the dwell run
    with FAST_TEXT and pay 20ms instead of 250."""
    hover(s, x, y)
    time.sleep(0.06)


def click(s, x, y):
    s.send(rf"\e[<0;{x + 1};{y + 1}M")
    s.send(rf"\e[<0;{x + 1};{y + 1}m")


def test_no_more_plus():
    """The frame carries no `+`, which is what lets the strip's new-tab button
    *be* a bare `+`: there is exactly one of them in the UI, so it means one
    thing. If a `+` ever returns to a frame, that button needs its word back.
    """
    with Session(SH, cols=60, rows=14, config=FAST) as s:
        s.settle()
        snap = s.snapshot()
        p = s.pane()
        check(
            "the frame has no split button any more",
            "+" not in snap.line(p["y"]),
            repr(snap.line(p["y"])),
        )
        check(
            "the status bar still has its own new-tab button",
            any(h["action"] == "newtab" and h["y"] == 1 for h in snap.hits),
            repr(snap.line(1)),
        )
        # The frame does spend columns again -- six of them, on the zoom and
        # close buttons -- but on two verbs that a single glyph *can* encode.
        # The split button was removed because one glyph cannot mean four
        # directions, not because buttons are forbidden. With them off, the row
        # is all title and rule again, and that is the stronger claim.
        check(
            "the title gets most of the row back",
            snap.line(p["y"]).count("─") > p["w"] - 20,
            repr(snap.line(p["y"])),
        )

    with Session(
        SH, cols=60, rows=14, config=cfg(FAST_TEXT + "pane_buttons false\n")
    ) as s:
        s.settle()
        snap, p = s.snapshot(), s.pane()
        check(
            "and all of it when the buttons are off",
            snap.line(p["y"]).count("─") > p["w"] - 12,
            repr(snap.line(p["y"])),
        )


def test_each_border_splits_toward_itself():
    for side, expect in [("r", "right"), ("l", "left"), ("b", "below"), ("t", "above")]:
        with Session(SH, cols=80, rows=26, config=FAST) as s:
            s.settle()
            before = s.pane()
            # The handle in the middle of that edge, not just any cell on it:
            # the rest of the edge deliberately does nothing.
            x, y = s.snapshot().handle(before["id"], side)
            click(s, x, y)
            s.settle(80)
            panes = s.panes()
            check(
                f"clicking the {side} border splits", len(panes) == 2, str(len(panes))
            )
            if len(panes) != 2:
                continue

            old = [q for q in panes if q["id"] == before["id"]][0]
            new = [q for q in panes if q["id"] != before["id"]][0]
            if expect == "right":
                ok = new["x"] > old["x"] and new["y"] == old["y"]
            elif expect == "left":
                ok = new["x"] < old["x"] and new["y"] == old["y"]
            elif expect == "below":
                ok = new["y"] > old["y"] and new["x"] == old["x"]
            else:
                ok = new["y"] < old["y"] and new["x"] == old["x"]
            check(
                f"the new pane lands {expect}",
                ok,
                f"old={old['x']},{old['y']} new={new['x']},{new['y']}",
            )
            check("and takes focus", new["focused"], str(new))
            said = {
                "r": "split right",
                "l": "split left",
                "b": "split down",
                "t": "split up",
            }[side]
            check(
                "and it says which way it went",
                said in s.snapshot().screen(),
                repr(s.snapshot().screen()[-80:]),
            )


def test_the_guide_escalates_from_edge_to_handle():
    """Two stages: the edge says *where the button is*, the handle says *what
    the click will do*. Hovering anywhere on an edge must show the first without
    the second, or brushing a border would still draw a boundary nobody asked
    about."""
    with Session(SH, cols=80, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()
        snap = s.snapshot()
        check(
            "no guide when the pointer is elsewhere",
            "┃" not in snap.screen() and "╎" not in snap.screen(),
            repr(snap.screen()[:120]),
        )

        rx, ry = snap.rim(p["id"], "l")
        rest(s, rx, ry)
        snap = s.snapshot()
        check(
            "hovering the rim of a side border arms it",
            "┃" in snap.screen(),
            repr(snap.screen()[:200]),
        )
        check(
            "and shows the handle you are meant to click",
            "█" in snap.screen(),
            repr(snap.screen()[:200]),
        )
        check(
            "but previews no boundary yet",
            "╎" not in snap.screen(),
            repr(snap.screen()[:200]),
        )

        hx, hy = snap.handle(p["id"], "l")
        rest(s, hx, hy)
        snap = s.snapshot()
        check(
            "on the handle it previews where the split would land",
            "╎" in snap.screen() and "█" in snap.screen(),
            repr(snap.screen()[:200]),
        )

        bx, by = snap.handle(p["id"], "b")
        rest(s, bx, by)
        snap = s.snapshot()
        check(
            "hovering the bottom handle arms that instead",
            "━" in snap.screen() and "╌" in snap.screen(),
            repr(snap.screen()[:200]),
        )
        check(
            "and the side guide is gone",
            "┃" not in snap.screen(),
            repr(snap.screen()[:200]),
        )

        rest(s, p["content_x"] + 3, p["content_y"] + 2)  # into the content
        snap = s.snapshot()
        check(
            "moving off a border puts the guide away",
            "━" not in snap.screen()
            and "┃" not in snap.screen()
            and "█" not in snap.screen(),
            repr(snap.screen()[:200]),
        )


def test_the_handle_thickens_by_a_column_never_a_row():
    """A cell is about twice as tall as it is wide, so the two axes cannot both
    grow by one and look the same. An upright handle takes a second column; a
    horizontal one stays on its own row and gets heavier instead, because two
    rows of block across a border reads as a wall and costs a row of output."""
    with Session(SH, cols=80, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()

        def blocks(snap):
            return [
                (x, y)
                for y, row in enumerate(snap.text)
                for x, ch in enumerate(row)
                if ch == "█"
            ]

        for side in ("t", "b"):
            hx, hy = s.snapshot().handle(p["id"], side)
            rest(s, hx, hy)
            cells = blocks(s.snapshot())
            rows = {y for _, y in cells}
            check(
                f"the {side} handle is one row tall",
                cells and rows == {hy},
                f"rows {sorted(rows)}, handle row {hy}",
            )

        for side in ("l", "r"):
            hx, hy = s.snapshot().handle(p["id"], side)
            rest(s, hx, hy)
            cells = blocks(s.snapshot())
            cols = {x for x, _ in cells}
            inward = hx + 1 if side == "l" else hx - 1
            check(
                f"the {side} handle is two columns wide",
                cells and cols == {hx, inward},
                f"columns {sorted(cols)}, wanted {sorted((hx, inward))}",
            )
            check(
                f"and the {side} handle's inner column is clickable",
                s.snapshot().hit_at(inward, hy) == f"border:{p['id']}:{side}",
                str(s.snapshot().hit_at(inward, hy)),
            )


def test_guide_follows_the_new_layout():
    """Regression: the guide described the layout from *before* the split.

    Hover state used to be remembered from the last motion event, so after a
    click split the guide stayed attached to the old pane and the old edge
    until the mouse moved and corrected it. It is derived during the paint
    now, from the rects that paint registered.
    """
    with Session(SH, cols=120, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()
        edge_x, edge_y = s.snapshot().handle(p["id"], "r")

        rest(s, edge_x, edge_y)
        click(s, edge_x, edge_y)
        s.settle(100)  # and deliberately no further mouse movement

        snap = s.snapshot()
        panes = s.panes()
        check("the split happened", len(panes) == 2, str(len(panes)))

        armed = [
            q
            for q in panes
            if "┃" in "".join(row[q["x"] : q["x"] + q["w"]] for row in snap.text)
        ]
        check("exactly one pane shows a guide", len(armed) == 1, str(armed))
        if len(armed) != 1:
            return
        check(
            "and it is the one the pointer is actually over",
            armed[0]["x"] <= edge_x < armed[0]["x"] + armed[0]["w"],
            f"pointer at {edge_x}, guide on {armed[0]['x']}..{armed[0]['x'] + armed[0]['w']}",
        )
        check(
            "on the edge the pointer is on",
            (snap.hit_at(edge_x, edge_y) or "").endswith(f"{armed[0]['id']}:r"),
            str(snap.hit_at(edge_x, edge_y)),
        )


def test_the_guide_waits_for_a_rest():
    """A pointer crossing a border on its way elsewhere must not flash it."""
    with Session(SH, cols=80, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()
        left, right = p["x"], p["x"] + p["w"] - 1
        row = p["y"] + 3

        hover(s, left, row)
        snap = s.snapshot()  # no dwell: this is the moment of contact
        check(
            "touching a border does not arm it immediately",
            "┃" not in snap.screen(),
            repr(snap.screen()[:160]),
        )

        # keep moving: across the pane and onto the other border
        hover(s, left + 6, row)
        hover(s, right, row)
        snap = s.snapshot()
        check(
            "passing over borders arms nothing",
            "┃" not in snap.screen(),
            repr(snap.screen()[:160]),
        )

        time.sleep(0.4)  # now rest
        snap = s.snapshot()
        check("resting on one arms it", "┃" in snap.screen(), repr(snap.screen()[:200]))
        check(
            "and it is the border being rested on",
            snap.hit_at(right, row)
            in (
                f"border:{p['id']}:r",
                f"brim:{p['id']}:r",
            ),
            str(snap.hit_at(right, row)),
        )

        hover(s, p["content_x"] + 2, row)
        snap = s.snapshot()
        check(
            "moving away disarms it at once",
            "┃" not in snap.screen(),
            repr(snap.screen()[:160]),
        )


def test_press_skips_the_wait():
    with Session(SH, cols=80, rows=26) as s:
        s.settle()
        p = s.pane()
        x, y = edge_of(s, p, "r")  # the handle: the rim answers no press
        s.send(rf"\e[<0;{x + 1};{y + 1}M")  # press and hold: that is intent
        snap = s.snapshot()
        check(
            "holding the button on a border arms it immediately",
            "┃" in snap.screen(),
            repr(snap.screen()[:200]),
        )
        s.send(rf"\e[<0;{x + 1};{y + 1}m")


def test_delay_is_configurable():
    import os
    import tempfile

    f = tempfile.NamedTemporaryFile("w", suffix=".kdl", delete=False)
    f.write("hover_delay_ms 0\n")
    f.close()
    with Session(SH, cols=80, rows=26, config=f.name) as s:
        s.settle()
        p = s.pane()
        hover(s, p["x"], p["y"] + 3)
        snap = s.snapshot()
        check(
            "with no delay configured it arms on contact",
            "┃" in snap.screen(),
            repr(snap.screen()[:160]),
        )
    os.unlink(f.name)


def test_guide_is_per_pane():
    with Session(SH, cols=150, rows=26, config=FAST) as s:
        s.settle()
        s.key("\\\\")
        s.settle()
        left, right = s.panes()
        rest(s, left["x"], left["y"] + 2)
        snap = s.snapshot()
        row = snap.line(left["y"] + 2)
        check(
            "the hovered pane is armed",
            "┃" in row[left["x"] : left["x"] + left["w"]],
            repr(row),
        )
        check(
            "the other one is not",
            "┃" not in row[right["x"] : right["x"] + right["w"]],
            repr(row),
        )


def test_drag_still_moves():
    """The top border does double duty: click splits, drag moves."""
    with Session(SH, cols=90, rows=26, config=FAST) as s:
        s.settle()
        s.key("\\\\")
        s.settle()
        left, right = s.panes()

        # drag: press, move, release -> swap, not split
        s.send(rf"\e[<0;{left['x'] + 5};{left['y'] + 1}M")
        s.send(rf"\e[<32;{right['x'] + 5};{right['y'] + 3}M")
        s.send(rf"\e[<0;{right['x'] + 5};{right['y'] + 3}m")
        s.settle(80)
        check(
            "dragging the top border still moves the pane",
            len(s.panes()) == 2,
            str(len(s.panes())),
        )
        panes = {q["id"]: q for q in s.panes()}
        check(
            "and swaps them",
            panes[left["id"]]["x"] > panes[right["id"]]["x"],
            str(s.panes()),
        )

        # click: press, release, no motion, on the handle -> split up. The rest
        # of the row is a drag handle only, which is the point of the handle.
        hx, hy = edge_of(s, s.panes()[0], "t")
        s.send(rf"\e[<0;{hx + 1};{hy + 1}M")
        s.send(rf"\e[<0;{hx + 1};{hy + 1}m")
        s.settle(80)
        check(
            "clicking its handle splits instead",
            len(s.panes()) == 3,
            str(len(s.panes())),
        )
        # and the rest of the row does not: the accident this whole shape exists
        # to stop. Counted from the pane the handle click just created.
        n = len(s.panes())
        top = s.panes()[0]
        rx, ry = s.snapshot().rim(top["id"], "t")
        s.send(rf"\e[<0;{rx + 1};{ry + 1}M")
        s.send(rf"\e[<0;{rx + 1};{ry + 1}m")
        s.settle(80)
        check(
            "while the rest of the row splits nothing",
            len(s.panes()) == n,
            f"{n} -> {len(s.panes())}",
        )


def test_tiny_panes_have_no_targets():
    with Session(SH, cols=90, rows=16, config=FAST) as s:
        s.settle()
        s.key("\\\\")
        s.settle()
        s.resize(30, 8)  # collapses to a stack
        s.settle(80)
        snap = s.snapshot()
        check(
            "a collapsed layout still draws and does not crash",
            s.api("alive")["alive"],
            "",
        )
        # Say what this means rather than pattern-matching on shape: a *header*
        # offers no split targets. The old form forbade any 1x1-ish border hit,
        # which also catches the legitimate side border of a very short pane
        # that is merely small, not collapsed.
        header_rows = {p["y"] for p in s.panes() if p["hidden"]}
        on_headers = [
            h
            for h in snap.hits
            if h["action"].startswith("border:") and h["y"] in header_rows
        ]
        check(
            "a collapsed header is a focus target, not a split one",
            not on_headers,
            str(on_headers),
        )


# ---- the floor: a split that is not worth making is not offered ------------

ARROWS = {"l": "\u25c4", "r": "\u25ba", "t": "\u25b2", "b": "\u25bc"}


def edge_of(s, pane, side):
    """The cell on that side that actually does something: its handle.

    Read out of the hit list rather than worked out here, so these tests cannot
    quietly agree with a geometry bug. The rest of an edge is the rim, which is
    what `Snapshot.rim` is for.
    """
    return s.snapshot().handle(pane["id"], side)


def test_a_split_below_the_floor_is_not_offered():
    """min_split is a usability floor, not the physical one: the pane below
    would still *fit* by min_pane, and is refused anyway."""
    conf = cfg(FAST_TEXT + "min_pane cols=10 rows=3\nmin_split cols=40 rows=14\n")
    with Session(SH, cols=80, rows=26, config=conf) as s:
        s.settle()
        p = s.pane()
        for side in ("l", "r", "t", "b"):
            x, y = edge_of(s, p, side)
            rest(s, x, y)
            snap = s.snapshot()
            body = snap.screen()
            check(
                f"resting on the {side} border arms nothing below the floor",
                "\u2503" not in body and "\u2501" not in body,
                repr(body[:80]),
            )
            click(s, x, y)
            s.settle(80)
            check(
                f"and clicking the {side} border splits nothing",
                len(s.panes()) == 1,
                str(len(s.panes())),
            )
    os.unlink(conf)


def test_the_floor_is_configurable_in_both_axes():
    # Wide enough for columns, too short for rows.
    conf = cfg(FAST_TEXT + "min_split cols=20 rows=40\n")
    with Session(SH, cols=90, rows=26, config=conf) as s:
        s.settle()
        p = s.pane()
        x, y = edge_of(s, p, "b")
        click(s, x, y)
        s.settle(80)
        check(
            "a row split below the row floor is refused",
            len(s.panes()) == 1,
            str(len(s.panes())),
        )
        x, y = edge_of(s, p, "r")
        click(s, x, y)
        s.settle(80)
        check(
            "while a column split above the column floor still happens",
            len(s.panes()) == 2,
            str(len(s.panes())),
        )
    os.unlink(conf)


def test_the_keyboard_obeys_the_same_floor():
    conf = cfg(FAST_TEXT + "min_split cols=40 rows=14\n")
    with Session(SH, cols=80, rows=26, config=conf) as s:
        s.settle()
        s.key("\\\\")
        s.settle(80)
        check(
            "the keyboard will not split below the floor either",
            len(s.panes()) == 1,
            str(len(s.panes())),
        )
        # ...but a script asking for a pane is declaring, not being offered.
        s.api("split", dir="cols")
        s.settle(80)
        check(
            "the control API is not bound by it",
            len(s.panes()) == 2,
            str(len(s.panes())),
        )
    os.unlink(conf)


def test_the_guide_says_which_way_it_goes():
    with Session(SH, cols=120, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()
        for side in ("l", "r", "t", "b"):
            x, y = edge_of(s, p, side)
            rest(s, x, y)
            body = s.snapshot().screen()
            check(
                f"the {side} guide carries its own arrow",
                ARROWS[side] in body,
                repr(ARROWS[side]),
            )
            others = [a for k, a in ARROWS.items() if k != side]
            check(
                f"and only that one",
                not any(o in body for o in others),
                repr(body[:80]),
            )


def test_the_arrow_rides_the_handle():
    """The arrow used to sit halfway along the dashed line, which split the
    message in two: the handle said *press here* and something out in the middle
    of the pane said *this is what happens*. It belongs on the button."""
    with Session(SH, cols=120, rows=26, config=FAST) as s:
        s.settle()
        p = s.pane()
        for side in ("l", "r", "t", "b"):
            hx, hy = edge_of(s, p, side)
            rest(s, hx, hy)
            snap = s.snapshot()
            pos = snap.find(ARROWS[side])
            # Inside the handle: same row for an upright edge, same column for a
            # horizontal one, and never out on the boundary line.
            near = pos is not None and (
                (side in "lr" and pos[1] == hy and abs(pos[0] - hx) <= 1)
                or (side in "tb" and pos[1] == hy and abs(pos[0] - hx) <= 3)
            )
            check(
                f"the {side} arrow is on the handle",
                near,
                f"{pos} vs handle ({hx},{hy})",
            )
            check(
                f"and the {side} boundary line carries none",
                pos != (p["x"] + p["w"] // 2, p["y"] + p["h"] // 2),
                str(pos),
            )

        # The arrow is part of the button, so it is legible from the first stage:
        # brushing an edge says which way that handle splits, without previewing
        # a boundary.
        rx, ry = s.snapshot().rim(p["id"], "l")
        rest(s, rx, ry)
        snap = s.snapshot()
        check(
            "and it shows on rim hover too, with no boundary",
            ARROWS["l"] in snap.screen() and "╎" not in snap.screen(),
            repr([l for l in snap.text if ARROWS["l"] in l][:1]),
        )


def test_the_top_handle_aims_at_the_middle_and_keeps_the_row_readable():
    """Two faults that fed each other.

    The handle went to the *widest* free run of the top row, and a centred title
    leaves two runs of nearly the same width — so a one-cell difference nobody
    can see threw it out toward a corner. And the armed edge ruled straight
    through the title, so the thing it sits beside was invisible, which is what
    made the position look arbitrary rather than merely off.
    """
    plain = ["/bin/sh", "-c", "stty raw -echo; cat"]
    with Session(plain, cols=110, rows=28, config=FAST) as s:
        s.settle()
        p = s.pane()
        e = [h for h in s.snapshot().hits if h["action"] == f"title:{p['id']}:t"][0]
        mid = p["x"] + p["w"] // 2
        centre = e["x"] + e["w"] // 2
        check(
            "with nothing in the way the handle is centred on the row",
            abs(centre - mid) <= 1,
            f"handle centre {centre}, row middle {mid}",
        )

    with Session(SH, cols=110, rows=28, config=FAST) as s:  # SH sets a title
        s.settle()
        p = s.pane()
        snap = s.snapshot()
        e = [h for h in snap.hits if h["action"] == f"title:{p['id']}:t"][0]
        name = [h for h in snap.hits if h["action"] == f"panetitle:{p['id']}"][0]
        check(
            "and when the title holds the middle it sits against it",
            e["x"] == name["x"] + name["w"] or e["x"] + e["w"] == name["x"],
            f"handle {e['x']}..{e['x'] + e['w'] - 1}, "
            f"title {name['x']}..{name['x'] + name['w'] - 1}",
        )

        # ...which only reads as deliberate if the armed edge leaves the title be.
        hx, hy = snap.handle(p["id"], "t")
        rest(s, hx, hy)
        row = s.snapshot().text[p["y"]]
        check(
            "the armed top edge does not rule through the name",
            "shell" in row,
            repr(row),
        )
        check(
            "nor through the buttons",
            all(m in row for m in ("▬", "□", "✕")),
            repr(row),
        )


# ---- `C-a Enter`: split whichever way there is room for -----------------------


def geometry(s):
    return [
        (p["x"], p["y"], p["w"], p["h"])
        for p in sorted(s.panes(), key=lambda q: (q["y"], q["x"]))
    ]


def toast_line(s):
    got = [
        l.strip()
        for l in s.snapshot().text
        if "split right" in l or "split down" in l or "no room" in l
    ]
    return got[-1] if got else ""


def test_it_splits_across_the_longer_side():
    """Longer as you *see* it: a cell is about twice as tall as it is wide, so a
    100x24 terminal is a wide pane and wants cutting into columns, while 60x40 is a
    tall one and wants rows. `gap_aspect` is the number that says so."""
    with Session(SH, cols=100, rows=24) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check(
            "a wide pane splits into columns",
            len(g) == 2 and g[0][1] == g[1][1],
            str(g),
        )
        check("side by side, evenly", g[0][2] == g[1][2], str(g))
        check(
            "and it says which way it went",
            toast_line(s) == "split right",
            repr(toast_line(s)),
        )

    with Session(SH, cols=60, rows=40) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check(
            "a tall pane splits into rows", len(g) == 2 and g[0][0] == g[1][0], str(g)
        )
        check("one above the other", g[1][1] > g[0][1], str(g))
        check("and says so", toast_line(s) == "split down", repr(toast_line(s)))


def test_the_aspect_is_the_configured_one():
    """`gap_aspect` is already this program's answer to how many columns a row is
    worth, so it is the number that decides "longer" -- one knob, one answer, rather
    than a second constant meaning the same thing.

    74x44 is the case that proves it: the pane is about 72x40, which is wider than it
    is tall in *cells* and taller than it is wide once a row counts double. Square
    cells split it into columns; the default splits it into rows.
    """
    square = cfg("gap_aspect 1\n")
    with Session(SH, cols=74, rows=44, config=square) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check(
            "with square cells, 72x40 splits into columns",
            len(g) == 2 and g[0][1] == g[1][1],
            str(g),
        )
    with Session(SH, cols=74, rows=44) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check(
            "...and with the default aspect, the same pane splits into rows",
            len(g) == 2 and g[0][0] == g[1][0],
            str(g),
        )
    os.unlink(square)


def test_it_falls_back_to_the_axis_that_fits():
    """The point of the action: on a pane that is wide but short the longer side is
    across, and if that does not fit the other one is tried before giving up."""
    # 150x14: the pane is 146x10 -- wide, so columns are preferred, and two columns
    # of 73 clear `min_split cols=32`. Rows would not (10 rows cannot make two of 8).
    with Session(SH, cols=150, rows=14) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check("wide and short splits into columns", g[0][1] == g[1][1], str(g))

    # 40x50: the pane is 36x46 -- tall, so rows, and 46 makes two of 8 easily while
    # 36 columns cannot make two of 32.
    with Session(SH, cols=40, rows=50) as s:
        s.settle()
        s.key(r"\r")
        s.settle(60)
        g = geometry(s)
        check("narrow and tall splits into rows", g[0][0] == g[1][0], str(g))
        check(
            "...even though columns is what a naive cell count would pick",
            g[1][1] > g[0][1],
            str(g),
        )


def test_no_room_says_so_rather_than_collapsing_the_tab():
    """A pane already under the floor cannot be split into two panes worth having by
    either axis -- and `split_fits` used to say yes, because it only asked about the
    dimension it was dividing. The answer was two panes the layout immediately
    collapsed into a list, from an action that was offered."""
    with Session(SH, cols=100, rows=8) as s:
        s.settle()
        before = geometry(s)
        s.key(r"\r")
        s.settle(60)
        check(
            "nothing was split",
            geometry(s) == before,
            "%s -> %s" % (before, geometry(s)),
        )
        check(
            "and it says why", toast_line(s) == "no room to split", repr(toast_line(s))
        )

    # The explicit keys answer the same way, because whether there is room cannot
    # depend on which key you asked with.
    with Session(SH, cols=100, rows=8) as s:
        s.settle()
        before = geometry(s)
        s.key("\\\\")
        s.settle(60)
        check("`C-a \\` refuses it too", geometry(s) == before, str(geometry(s)))
        check(
            "...in its own words",
            "no room to split across" in s.snapshot().screen(),
            repr(s.snapshot().screen()[-100:]),
        )


def test_it_is_on_the_sheet_and_in_the_palette():
    with Session(SH, cols=100, rows=30) as s:
        s.settle()
        s.send(r"\x01?")
        s.settle(60)
        sheet = s.snapshot().screen()
        check(
            "the sheet lists it",
            "split the longer way" in sheet,
            repr([l.strip() for l in s.snapshot().text if "longer" in l]),
        )
        check("under Enter", "enter" in sheet.lower(), "")
        s.send(r"\e")
        s.settle(40)
        s.send(r"\x01p")
        s.settle(40)
        s.send("longer")
        s.settle(60)
        check(
            "and the palette finds it",
            "split the longer way" in s.snapshot().screen(),
            repr([l.strip() for l in s.snapshot().text if "longer" in l]),
        )


if __name__ == "__main__":
    test_no_more_plus()
    test_each_border_splits_toward_itself()
    test_the_guide_escalates_from_edge_to_handle()
    test_the_handle_thickens_by_a_column_never_a_row()
    test_guide_follows_the_new_layout()
    test_the_guide_waits_for_a_rest()
    test_press_skips_the_wait()
    test_delay_is_configurable()
    test_guide_is_per_pane()
    test_drag_still_moves()
    test_tiny_panes_have_no_targets()
    test_a_split_below_the_floor_is_not_offered()
    test_the_floor_is_configurable_in_both_axes()
    test_the_keyboard_obeys_the_same_floor()
    test_the_guide_says_which_way_it_goes()
    test_the_arrow_rides_the_handle()
    test_the_top_handle_aims_at_the_middle_and_keeps_the_row_readable()
    test_it_splits_across_the_longer_side()
    test_the_aspect_is_the_configured_one()
    test_it_falls_back_to_the_axis_that_fits()
    test_no_room_says_so_rather_than_collapsing_the_tab()
    test_it_is_on_the_sheet_and_in_the_palette()
    sys.exit(report())