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"""Tests for ``pn.Easing``: descriptors, the Python evaluator, and the wire form.""" from __future__ import annotations import time from typing import Any import pytest from pythonnative.animated import EASING_NAMES, Animated, AnimatedValue, Easing, EasingSpec from pythonnative.native_views import set_backend from pythonnative.testing import FakeBackend # ====================================================================== # Descriptors # ====================================================================== def test_easing_namespace_exposes_frozen_specs() -> None: assert EASING_NAMES == ("linear", "ease", "ease_in", "ease_out", "ease_in_out", "quad", "cubic", "bounce") for name in EASING_NAMES: spec = getattr(Easing, name) assert isinstance(spec, EasingSpec) assert spec.name == name and spec.points is None assert spec.to_wire() == name with pytest.raises(Exception): Easing.linear.name = "other" # type: ignore[misc] def test_bezier_descriptor_carries_control_points() -> None: spec = Easing.bezier(0.2, 0.8, 0.2, 1.0) assert spec == EasingSpec("bezier", (0.2, 0.8, 0.2, 1.0)) assert spec.to_wire() == [0.2, 0.8, 0.2, 1.0] assert repr(spec) == "Easing.bezier(0.2, 0.8, 0.2, 1.0)" assert repr(Easing.ease_out) == "Easing.ease_out" def test_bezier_validation() -> None: with pytest.raises(ValueError): Easing.bezier(1.5, 0.0, 0.5, 1.0) # x1 outside [0, 1] with pytest.raises(ValueError): Easing.bezier(0.5, 0.0, -0.1, 1.0) # x2 outside [0, 1] # y values may overshoot (anticipation and overshoot curves). Easing.bezier(0.34, 1.56, 0.64, 1.0) with pytest.raises(ValueError): EasingSpec("bezier") with pytest.raises(ValueError): EasingSpec("wobble") with pytest.raises(ValueError): EasingSpec("linear", (0.0, 0.0, 1.0, 1.0)) # ====================================================================== # Evaluator # ====================================================================== def test_named_curves_evaluate_to_reference_values() -> None: assert Easing.linear.evaluate(0.3) == 0.3 assert Easing.quad.evaluate(0.5) == 0.25 assert Easing.cubic.evaluate(0.5) == 0.125 assert Easing.bounce.evaluate(0.0) == 0.0 assert abs(Easing.bounce.evaluate(1.0) - 1.0) < 1e-12 # Penner bounce-out midway through the first arc. assert abs(Easing.bounce.evaluate(0.2) - 7.5625 * 0.2 * 0.2) < 1e-12 for name in EASING_NAMES: spec = getattr(Easing, name) assert spec.evaluate(0.0) == 0.0 assert abs(spec.evaluate(1.0) - 1.0) < 1e-9 def test_ease_family_matches_react_native_definitions() -> None: # ease == bezier(0.42, 0, 1, 1) (React Native's Easing.ease); in/out/in_out derive from it. for t in (0.1, 0.25, 0.5, 0.75, 0.9): assert abs(Easing.ease.evaluate(t) - Easing.bezier(0.42, 0.0, 1.0, 1.0).evaluate(t)) < 1e-9 assert abs(Easing.ease_in.evaluate(t) - Easing.ease.evaluate(t)) < 1e-9 # Easing.out(f)(t) == 1 - f(1 - t) assert abs(Easing.ease_out.evaluate(t) - (1.0 - Easing.ease.evaluate(1.0 - t))) < 1e-6 assert Easing.ease_in.evaluate(0.5) < 0.5 < Easing.ease_out.evaluate(0.5) assert abs(Easing.ease_in_out.evaluate(0.5) - 0.5) < 1e-6 assert Easing.ease_in_out.evaluate(0.25) < 0.25 and Easing.ease_in_out.evaluate(0.75) > 0.75 def test_cubic_bezier_solver_inverts_the_parametric_curve() -> None: """For sampled parameter values, evaluate(x(t)) must return y(t).""" def component(t: float, p1: float, p2: float) -> float: inv = 1.0 - t return 3 * inv * inv * t * p1 + 3 * inv * t * t * p2 + t * t * t curves = [ (0.2, 0.8, 0.2, 1.0), (0.42, 0.0, 0.58, 1.0), (0.34, 1.56, 0.64, 1.0), (1.0, 0.0, 0.0, 1.0), (0.0, 0.0, 1.0, 1.0), ] for x1, y1, x2, y2 in curves: spec = Easing.bezier(x1, y1, x2, y2) for i in range(1, 50): t = i / 50 x = component(t, x1, x2) y = component(t, y1, y2) assert abs(spec.evaluate(x) - y) < 1e-5, (x1, y1, x2, y2, t) def test_bezier_clamps_progress_outside_unit_interval() -> None: spec = Easing.bezier(0.2, 0.8, 0.2, 1.0) assert spec.evaluate(-0.5) == 0.0 assert spec.evaluate(1.5) == 1.0 # ====================================================================== # Animated.timing integration # ====================================================================== class _RecordingBackend(FakeBackend): def __init__(self) -> None: super().__init__() self.native_started: list = [] def start_animation(self, tag: int, anim_id: int, prop_name: str, spec: Any) -> bool: self.native_started.append((tag, anim_id, prop_name, dict(spec))) return True def cancel_animation(self, tag: int, anim_id: int) -> Any: return None @pytest.fixture def backend(): # type: ignore[no-untyped-def] backend = _RecordingBackend() set_backend(backend) try: yield backend finally: set_backend(None) def test_timing_rejects_unknown_easing_names() -> None: v = AnimatedValue(0.0) with pytest.raises(ValueError, match="Unknown easing"): Animated.timing(v, to=1.0, easing="ease_in_quad") with pytest.raises(ValueError): Animated.timing(v, to=1.0, easing="eas_in_out") with pytest.raises(TypeError): Animated.timing(v, to=1.0, easing=42) # type: ignore[arg-type] def test_timing_serializes_named_and_bezier_easings(backend: _RecordingBackend) -> None: v = AnimatedValue(0.0) v.attach(7, "opacity") Animated.timing(v, to=1.0, duration=500, easing="ease_out").start() Animated.timing(v, to=1.0, duration=500, easing=Easing.bounce).start() Animated.timing(v, to=1.0, duration=500, easing=Easing.bezier(0.2, 0.8, 0.2, 1.0)).start() Animated.timing(v, to=1.0, duration=500).start() wire = [spec["easing"] for _tag, _id, _prop, spec in backend.native_started] assert wire == ["ease_out", "bounce", [0.2, 0.8, 0.2, 1.0], "ease_in_out"] def test_callable_easing_disables_the_native_driver(backend: _RecordingBackend) -> None: v = AnimatedValue(0.0) v.attach(7, "opacity") handle = Animated.timing(v, to=1.0, duration=30, easing=lambda t: t * t) handle.start() assert backend.native_started == [] deadline = time.monotonic() + 2.0 while time.monotonic() < deadline and v.value < 0.99: time.sleep(0.01) assert abs(v.value - 1.0) < 0.05 @pytest.mark.asyncio async def test_timing_with_bezier_easing_runs_on_python_ticker() -> None: v = AnimatedValue(0.0) seen: list = [] v.add_listener("x", seen.append) result = await Animated.timing(v, to=1.0, duration=60, easing=Easing.bezier(0.2, 0.8, 0.2, 1.0)) assert result.finished is True assert abs(v.value - 1.0) < 1e-9 assert seen == sorted(seen), "an ease-out style bezier should be monotonic"