Jean-Pierre MartineauandClaude Opus 5.5
11b5274b31
Each test docstring states the behaviour that the test proves, in the simple present. No assertion message, test id, or other string literal changed. Four statements now agree with the code: the Trace highlight stays on the last row, a menu count, and two others. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
91 lines
4.2 KiB
Python
91 lines
4.2 KiB
Python
# SPDX-License-Identifier: Apache-2.0
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"""Tests for ``ui/oklab.py``, the perceptual colour space for the seam and its shade."""
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from __future__ import annotations
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import pytest
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from meshterm.ui import oklab
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from meshterm.ui.theme import _node_style_spectrum
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def _fill(key: str) -> str:
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return _node_style_spectrum(key).split()[-1]
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def test_every_node_fill_round_trips_through_oklab_exactly() -> None:
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"""Hex to Lab to hex is lossless on all 256 spectrum fills and the fixed greys."""
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for byte in range(256):
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colour = _fill(f"{byte:02x}")
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assert oklab.to_hex(oklab.from_hex(colour)) == colour
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for grey in ("#000000", "#ffffff", "#64748b", "#334155", "#3f3f46"):
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assert oklab.to_hex(oklab.from_hex(grey)) == grey
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def test_lightness_runs_black_to_white_and_distance_is_a_metric() -> None:
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"""``L`` spans 0–1, the distance from black to white is 1, and the distance is symmetric."""
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black, white = oklab.from_hex("#000000"), oklab.from_hex("#ffffff")
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assert black[0] == pytest.approx(0.0, abs=1e-6) and white[0] == pytest.approx(1.0, abs=1e-3)
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assert oklab.distance("#000000", "#ffffff") == pytest.approx(1.0, abs=1e-3)
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assert oklab.distance("#f25555", "#f25555") == 0.0
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assert oklab.distance("#f25555", "#5557f2") == oklab.distance("#5557f2", "#f25555")
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def test_the_wheel_is_not_uniform_to_the_eye() -> None:
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"""One hue step is small in green and large in cyan. This is why the module exists."""
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green = oklab.distance(_fill("4c"), _fill("5c"))
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cyan = oklab.distance(_fill("80"), _fill("90"))
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assert green < 0.03 < 0.15 < cyan
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def test_shaded_moves_lightness_alone_away_from_the_nearer_end() -> None:
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"""A light colour is returned darker and a dark colour lighter. The chroma is the same."""
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light, dark = "#55f255", "#334155"
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for colour, sign in ((light, -1), (dark, +1)):
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before, after = oklab.from_hex(colour), oklab.from_hex(oklab.shaded(colour, 0.1))
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assert (after[0] - before[0]) * sign == pytest.approx(0.1, abs=0.01)
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assert after[1] == pytest.approx(before[1], abs=0.02) # in-gamut: chroma kept
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assert after[2] == pytest.approx(before[2], abs=0.02)
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def test_shaded_floor_clears_a_second_colour_too() -> None:
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"""With a floor, the shift starts from the lightness that is further along."""
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a, b = _fill("4c"), _fill("5c") # b is the darker of two similar greens
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plain = oklab.shaded(a, 0.15)
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floored = oklab.shaded(a, 0.15, floor=oklab.from_hex(b)[0])
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assert oklab.from_hex(floored)[0] <= oklab.from_hex(plain)[0]
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assert oklab.from_hex(b)[0] - oklab.from_hex(floored)[0] == pytest.approx(0.15, abs=0.01)
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slate, lighter_slate = "#334155", "#3f3f46" # dark: the floor pushes up instead
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floored = oklab.shaded(slate, 0.15, floor=oklab.from_hex(lighter_slate)[0])
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assert oklab.from_hex(floored)[0] >= oklab.from_hex(oklab.shaded(slate, 0.15))[0]
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def test_fitted_lowers_chroma_alone_and_keeps_near_hues_apart() -> None:
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"""A colour outside the gamut is returned inside it, with its lightness and hue.
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A colour in the gamut is returned unchanged. The clip in ``to_hex`` made two dark
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greens near ``0x50`` almost one colour. After the fit, they are clearly two colours.
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"""
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inside = oklab.from_hex(_fill("80"))
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assert oklab.fitted(inside) == inside
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darker = [oklab.from_hex(_fill(key)) for key in ("4c", "5c")]
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outside = [(lab[0] * 0.6, lab[1], lab[2]) for lab in darker]
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fits = [oklab.fitted(lab) for lab in outside]
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clipped = oklab.distance(*(oklab.to_hex(lab) for lab in outside))
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assert oklab.distance(*(oklab.to_hex(lab) for lab in fits)) > 2 * clipped
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for before, after in zip(outside, fits, strict=True):
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assert after[0] == before[0]
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assert after[1] / before[1] == pytest.approx(after[2] / before[2]) # the same hue
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assert abs(after[1]) < abs(before[1]) # less chroma
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def test_from_hex_rejects_anything_but_six_digits() -> None:
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"""Six hex digits are accepted, and the ``#`` and the case are optional.
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All other text raises a ``ValueError``.
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"""
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with pytest.raises(ValueError):
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oklab.from_hex("#fff")
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assert oklab.from_hex("F25555") == oklab.from_hex("#f25555")
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