feat(palette): sixteen ANSI colour ladders, cycled with c

tests/test_palettes.py

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+"""The colour palettes: sixteen ladders of ANSI names, and the `c` key."""
+
+from __future__ import annotations
+
+import html
+import re
+
+import pytest
+
+from beefy_player import config
+from beefy_player.app import BeefyPlayerApp
+from beefy_player.palettes import (
+    DEFAULT_PALETTE,
+    PALETTE_ORDER,
+    PALETTES,
+    palette_stops,
+)
+from beefy_player.widgets import frame
+from beefy_player.widgets.help import HelpScreen
+from beefy_player.widgets.station_list import StationList
+
+ANSI_NAMES = {
+    "black",
+    "red",
+    "green",
+    "yellow",
+    "blue",
+    "magenta",
+    "cyan",
+    "white",
+    "bright_black",
+    "bright_red",
+    "bright_green",
+    "bright_yellow",
+    "bright_blue",
+    "bright_magenta",
+    "bright_cyan",
+    "bright_white",
+}
+
+
+def test_there_are_sixteen_palettes_of_ansi_names() -> None:
+    assert len(PALETTES) == 16
+    assert len(PALETTE_ORDER) == 16
+    assert len(set(PALETTE_ORDER)) == 16
+    assert DEFAULT_PALETTE in PALETTES
+
+    for name, stops in PALETTES.items():
+        assert len(stops) >= 3, name
+        assert set(stops) <= ANSI_NAMES, (name, set(stops) - ANSI_NAMES)
+        # a ladder, not a list: the quiet end must differ from the hot end
+        assert stops[0] != stops[-1], name
+
+
+def test_a_broken_palette_name_falls_back_to_the_default() -> None:
+    assert palette_stops("mono") == PALETTES["mono"]
+    assert palette_stops(" MONO ") == PALETTES["mono"]
+    assert palette_stops("no-such-palette") == PALETTES[DEFAULT_PALETTE]
+    assert palette_stops(None) == PALETTES[DEFAULT_PALETTE]
+
+
+def test_the_config_remembers_the_palette() -> None:
+    assert config.Config.load().palette == DEFAULT_PALETTE
+    config.Config(palette="ember").save()
+    assert config.Config.load().palette == "ember"
+
+
+def test_an_unknown_palette_in_the_config_is_ignored() -> None:
+    config.CONFIG_PATH.parent.mkdir(parents=True, exist_ok=True)
+    config.CONFIG_PATH.write_text('{"palette": "chartreuse"}')
+    assert config.Config.load().palette == DEFAULT_PALETTE
+
+
+@pytest.mark.asyncio
+async def test_the_c_key_cycles_and_remembers_the_palette() -> None:
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(100, 30)) as pilot:
+        await pilot.pause()
+        start = app.palette
+        assert start == DEFAULT_PALETTE
+
+        await pilot.press("c")
+        await pilot.pause()
+        expected = PALETTE_ORDER[(PALETTE_ORDER.index(start) + 1) % len(PALETTE_ORDER)]
+        assert app.palette == expected
+        assert app.config.palette == expected
+        assert "palette" in app.notice
+
+        # the choice survives a restart
+        config.Config(palette=app.palette).save()
+        assert config.Config.load().palette == expected
+
+
+@pytest.mark.asyncio
+async def test_the_pane_corners_follow_the_palette() -> None:
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(100, 30)) as pilot:
+        await pilot.pause()
+        pane = app.query_one(StationList)
+
+        app.palette = "mono"
+        mono = [str(span.style) for span in pane.render().renderables[0].spans]
+        app.palette = "ember"
+        ember = [str(span.style) for span in pane.render().renderables[0].spans]
+
+        assert mono != ember
+        assert any("bright_white" in style for style in mono)
+        # ember's hot end is white too, but its quiet end is not
+        assert any(PALETTES["ember"][-2] in style for style in ember)
+
+
+@pytest.mark.asyncio
+async def test_the_spectrum_rows_use_the_active_palette() -> None:
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(100, 30)) as pilot:
+        await pilot.pause()
+        spectrum = app.query_one("SpectrumPanel")
+
+        def colours(styles: list[str]) -> set[str]:
+            return {
+                style.replace("dim ", "").replace("bold ", "").strip()
+                for style in styles
+            }
+
+        app.palette = "mono"
+        spectrum.refresh()
+        await pilot.pause()
+        assert colours(spectrum._row_palette(12, 0, False)) <= set(PALETTES["mono"])
+
+        app.palette = "neon"
+        spectrum.refresh()
+        await pilot.pause()
+        assert colours(spectrum._row_palette(12, 0, False)) <= set(PALETTES["neon"])
+
+
+def test_the_corner_fade_walks_back_down_the_ladder() -> None:
+    stops = PALETTES["spectrum"]
+    assert frame.corner_fade(0, stops) == stops[-1]
+    assert frame.corner_fade(1, stops) == stops[-2]
+    assert frame.corner_fade(3, stops) == stops[-4]
+    # the fade is short: past four cells it is just the border grey
+    assert frame.corner_fade(4, stops) == frame.EDGE
+
+
+@pytest.mark.asyncio
+async def test_the_help_scrolls_when_the_terminal_is_short() -> None:
+    """The help page is ~56 rows: it must be readable on a 24-row screen."""
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(80, 24)) as pilot:
+        await pilot.pause()
+        await pilot.press("question_mark")
+        await pilot.pause()
+        body = app.screen.query_one("#help")
+        assert body.size.height < body.virtual_size.height
+        assert body.max_scroll_y > 0
+        assert body.scroll_y == 0
+
+        await pilot.press("pagedown")
+        await pilot.pause()
+        assert body.scroll_y > 0
+
+        await pilot.press("end")
+        await pilot.pause()
+        assert body.scroll_y == body.max_scroll_y
+
+        await pilot.press("home")
+        await pilot.pause()
+        assert body.scroll_y == 0
+
+        await pilot.press("x")
+        await pilot.pause()
+        assert not isinstance(app.screen, HelpScreen)
+
+
+@pytest.mark.asyncio
+async def test_a_tall_terminal_needs_no_scrolling() -> None:
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(120, 70)) as pilot:
+        await pilot.pause()
+        await pilot.press("question_mark")
+        await pilot.pause()
+        body = app.screen.query_one("#help")
+        assert body.max_scroll_y == 0
+
+
+@pytest.mark.asyncio
+async def test_the_help_lists_every_palette_and_marks_the_active_one() -> None:
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(120, 64)) as pilot:
+        await pilot.pause()
+        app.palette = "ocean"
+        await pilot.press("question_mark")
+        await pilot.pause()
+        text = html.unescape(app.export_screenshot()).replace("\xa0", " ")
+        text = re.sub(r"<[^>]+>", "", text)
+
+        assert "PALETTES" in text
+        assert "c cycles them" in text
+        for name in PALETTE_ORDER:
+            assert name in text, name
+        assert "● ocean" in text
+        # each palette shows a swatch of eight blocks
+        assert "████████" in text
+
+
+@pytest.mark.asyncio
+async def test_the_help_footer_attributes_the_build() -> None:
+    """One line: the version and the project URL — no credits essay."""
+    from beefy_player import __version__
+
+    app = BeefyPlayerApp(autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(110, 70)) as pilot:
+        await pilot.pause()
+        await pilot.press("question_mark")
+        await pilot.pause()
+        body = app.screen.query_one("#help")
+        body.scroll_end(animate=False)
+        await pilot.pause()
+
+        text = html.unescape(app.export_screenshot()).replace("\xa0", " ")
+        text = re.sub(r"<[^>]+>", "", text)
+
+        assert f"beefy player {__version__}" in text
+        assert "https://tildeforge.dev/beefcarver/beefy-player" in text
+        # the old explanatory blurb is gone
+        assert "playerctl" not in text
+        assert "parec" not in text
+        assert "Stations and song history come from" not in text
+
+
+@pytest.mark.parametrize("slug", ["bassdrive", "somafm"])
+@pytest.mark.asyncio
+async def test_the_help_has_no_pane_explainer(slug: str) -> None:
+    """No catalogue gets a paragraph about its left pane."""
+    app = BeefyPlayerApp(provider=slug, autoplay=False, offline=True, audio=False)
+    async with app.run_test(size=(110, 60)) as pilot:
+        await pilot.pause()
+        await pilot.press("question_mark")
+        await pilot.pause()
+        text = html.unescape(app.export_screenshot()).replace("\xa0", " ")
+        text = re.sub(r"<[^>]+>", "", text)
+        assert "is a single stream" not in text
+        assert "multi-station catalogues" not in text
+        assert "CATALOGUES" in text