Files
brain-of-reese/tests/unit/test_background_no_motion.py
T

253 lines
11 KiB
Python

"""Unit: the phase-25 still-background contract (source pins).
Owner report (2026-08-25, chat): the animated background "jitters down
and to the right every second and it slowly blinks brighter and darker.
It should be smooth, fluxuating, dimming and brightening, but not
moving. Different bright spots should slowly fade in and out."
The diagnosis (`.agent/reports/25_background_no_motion/`) found both
root causes in the phase-22 design:
- "jitters down and to the right" = the grid's 44px/60s drift
(0.73px/s, diagonally down-right) — a 1px grid line translated
sub-pixel by sub-pixel rasterizes with per-frame stepping;
- "slowly blinks" = the whole-layer 14s opacity 0.85↔1 +
scale(1)↔scale(1.05) pulse — one synchronized pulse reads as a blink.
The fix (styles.css, pure CSS, zero JS, no `filter` — A11): the grid is
a STATIC texture (no animation, no bg-grid-drift keyframes), and three
independent soft glow spots (body::after, html::before, html::after)
each run their own SLOW opacity-only fade (26/34/42s, ease-in-out,
negative delays → out of phase; LCM 4641s → the composite pattern
effectively never repeats within a viewing session), so the total light
fluxuates smoothly and irregularly — no blink, no jitter, no movement.
Story: .agent/user_stories/background-no-motion.md. Browser behavior
(no motion, visible fades, no occlusion, no overflow) is E2E-covered by
tests/e2e/test_background_no_motion.py (task 02).
"""
from __future__ import annotations
import re
from tests.unit.test_background_animation import _css, _css_no_comments, _rule_block
ALL_LAYERS = ("body::before", "body::after", "html::before", "html::after")
# (layer, keyframes name, duration shorthand, single-spot gradient)
GLOW_SPOTS = (
("body::after", "bg-glow-a", "animation: bg-glow-a 26s ease-in-out infinite",
"radial-gradient(circle 56rem at 12% 8%, rgb(109 120 242 / 0.14), transparent 62%)"),
("html::before", "bg-glow-b", "animation: bg-glow-b 34s ease-in-out -12s infinite",
"radial-gradient(circle 60rem at 88% 92%, rgb(34 211 238 / 0.10), transparent 62%)"),
("html::after", "bg-glow-c", "animation: bg-glow-c 42s ease-in-out -23s infinite",
"radial-gradient(circle 52rem at 14% 86%, rgb(109 120 242 / 0.09), transparent 62%)"),
)
def _bg_keyframes(css: str) -> dict[str, str]:
"""Name → body for every @keyframes bg-* rule (balanced braces —
works for the one-line blocks and a multi-line reformat alike)."""
out: dict[str, str] = {}
for m in re.finditer(r"@keyframes (bg-[A-Za-z0-9-]+)\s*\{", css):
start, depth, i = m.end(), 1, m.end()
while i < len(css) and depth:
if css[i] == "{":
depth += 1
elif css[i] == "}":
depth -= 1
i += 1
out[m.group(1)] = css[start:i - 1]
return out
# --------------------------------------------------------------------------
# No movement — the grid is a static texture, and no bg-* keyframe may
# animate anything but opacity
# --------------------------------------------------------------------------
def test_grid_has_no_animation() -> None:
"""body::before must carry NO animation declaration — the phase-22
0.73px/s drift rasterized as a once-per-second down-right jitter; the
owner wants no movement (2026-08-25)."""
block = _rule_block(_css(), "body::before")
assert "animation" not in block, (
"body::before must not animate (the no-movement contract)"
)
def test_drift_and_breathe_keyframes_are_deleted() -> None:
"""@keyframes bg-grid-drift and @keyframes bg-glow-breathe are gone —
the names must not appear anywhere in the file (no declaration, no
keyframe block, no stale comment)."""
css = _css()
assert "bg-grid-drift" not in css, "bg-grid-drift must be deleted"
assert "bg-glow-breathe" not in css, "bg-glow-breathe must be deleted"
def test_grid_keeps_its_static_texture() -> None:
"""The owner rejected the grid's MOTION, not the grid: 44px cells,
1px lines at 60% --line alpha, and the widened radial mask (both the
-webkit- and standard mask properties) stay."""
block = _rule_block(_css(), "body::before")
assert "background-size: 44px 44px" in block
assert (
"linear-gradient(to right, rgb(38 48 74 / 0.6) 1px, transparent 1px)" in block
), "grid must keep horizontal 1px lines at 60% --line"
assert (
"linear-gradient(to bottom, rgb(38 48 74 / 0.6) 1px, transparent 1px)" in block
), "grid must keep vertical 1px lines at 60% --line"
mask = "radial-gradient(140% 110% at 50% 0%, black 40%, transparent 90%)"
assert f"-webkit-mask-image: {mask};" in block
assert f"mask-image: {mask};" in block
def test_exactly_three_bg_glow_keyframes_exist() -> None:
"""Exactly three bg-* keyframe blocks: bg-glow-a/b/c (the old
bg-grid-drift and bg-glow-breathe are deleted)."""
assert set(_bg_keyframes(_css())) == {"bg-glow-a", "bg-glow-b", "bg-glow-c"}
def test_bg_keyframes_animate_opacity_only() -> None:
"""The no-movement contract: across ALL frames of ALL bg-* keyframes
the set of declared properties is exactly {opacity} — no transform,
scale, background-position, nothing else may appear."""
props: set[str] = set()
for _name, body in _bg_keyframes(_css()).items():
props |= set(re.findall(r"([A-Za-z-]+)\s*:", body))
assert props == {"opacity"}, (
f"bg-* keyframes must animate only opacity, found {sorted(props)}"
)
def test_glow_layers_declare_no_transform_or_position_animation() -> None:
"""The three glow layers themselves must not declare transform or
background-position either (the no-movement contract applies to the
layers, not just their keyframes)."""
for sel, _name, _anim, _grad in GLOW_SPOTS:
block = _rule_block(_css(), sel)
assert "transform" not in block, f"{sel} must not declare transform"
assert "background-position" not in block, (
f"{sel} must not declare background-position"
)
# --------------------------------------------------------------------------
# Three distinct bright spots, each on its own slow opacity-only fade
# --------------------------------------------------------------------------
def test_each_spot_runs_its_own_slow_opacity_fade() -> None:
"""body::after (phase-08 indigo, 26s), html::before (phase-08 cyan,
34s, -12s delay), html::after (third indigo, 42s, -23s delay) — each
glow layer's background-image is EXACTLY the single radial gradient
from the spec (color, radius, position, 62% transparent stop)."""
for sel, _name, animation, gradient in GLOW_SPOTS:
block = _rule_block(_css(), sel)
assert animation in block, f"{sel} must run {animation}"
assert f"background-image: {gradient};" in block, (
f"{sel} must carry exactly one radial gradient: {gradient}"
)
def test_glow_durations_are_distinct_and_slow() -> None:
"""The three cycles are out of phase (distinct durations) and each is
slow (>= 20s); LCM(26, 34, 42) = 4641s, so the composite pattern
effectively never repeats within a viewing session."""
durations: list[float] = []
for sel, name, _anim, _grad in GLOW_SPOTS:
block = _rule_block(_css(), sel)
m = re.search(rf"animation: {name}\s+([\d.]+)s", block)
assert m, f"{sel} must run its {name} fade"
durations.append(float(m.group(1)))
assert len(set(durations)) == len(durations), (
"the three spot cycles must be out of phase (distinct durations)"
)
assert all(d >= 20 for d in durations), (
f"each spot fade must be slow (>= 20s), got {durations}"
)
def test_glow_keyframes_low_and_high_opacities() -> None:
"""Each cycle: 0%/100% at its own low opacity (0.25 / 0.20 / 0.15),
50% at 1 — smooth fade in and out, never a hard cut."""
keyframes = _bg_keyframes(_css())
lows = {"bg-glow-a": 0.25, "bg-glow-b": 0.20, "bg-glow-c": 0.15}
for name, low in lows.items():
body = keyframes[name]
m = re.search(r"0%,\s*100%\s*\{\s*opacity:\s*([\d.]+)\s*;\s*\}", body)
assert m and float(m.group(1)) == low, (
f"{name} must start/end at opacity {low}"
)
m = re.search(r"50%\s*\{\s*opacity:\s*([\d.]+)\s*;\s*\}", body)
assert m and float(m.group(1)) == 1.0, (f"{name} must peak at opacity 1")
# --------------------------------------------------------------------------
# Layer plumbing — the no-occlusion contract across all four layers
# --------------------------------------------------------------------------
def test_all_four_layers_are_fixed_zminus1_noninteractive() -> None:
"""All four background pseudo-layers stay behind the content and can
never intercept input: fixed, full-viewport, z-index -1,
pointer-events none, with pseudo content (UI Structure Check: layers
behind content, no 360px overflow — the layers are fixed; inset: 0)."""
for sel in ALL_LAYERS:
block = _rule_block(_css(), sel)
assert "position: fixed" in block, f"{sel} must stay position:fixed"
assert "inset: 0" in block, f"{sel} must stay full-viewport (inset: 0)"
assert "z-index: -1" in block, f"{sel} must stay z-index:-1"
assert "pointer-events: none" in block, f"{sel} must stay click-through"
assert 'content: ""' in block, f"{sel} must keep its pseudo content"
def test_html_owns_canvas_and_body_stays_transparent() -> None:
"""The no-occlusion contract: <html> keeps the var(--bg) canvas;
<body> stays transparent and non-stacking — or the z-index:-1 layers
(including the new html::before / html::after spots) would be painted
over."""
html_block = _rule_block(_css(), "html")
assert "background: var(--bg)" in html_block, (
"html must keep background: var(--bg) (the page canvas)"
)
body_block = _rule_block(_css(), "body")
assert "background: transparent" in body_block, (
"body must keep background: transparent so the layers show"
)
for prop in ("z-index", "transform", "opacity", "filter"):
assert prop + ":" not in body_block, (
f"body must not create a stacking context (found {prop})"
)
# --------------------------------------------------------------------------
# Reduced motion + phase-08 anchors (no filter, no blur, zero JS)
# --------------------------------------------------------------------------
def test_reduced_motion_stills_all_four_layers() -> None:
"""prefers-reduced-motion: reduce must still ALL FOUR layers together
(body::before, body::after, html::before, html::after) with
animation: none — the typing/spinner/thinking blocks are untouched."""
blocks = re.findall(
r"@media \(prefers-reduced-motion: reduce\)\s*\{([\s\S]*?)\n\}", _css()
)
assert any(
all(sel in b for sel in ALL_LAYERS) and "animation: none" in b
for b in blocks
), "a reduced-motion block must still all four background layers"
def test_no_filter_in_any_layer_and_no_blur_anywhere() -> None:
"""The phase-08 performance anchor: no `filter` in any background
layer block, and no `blur` anywhere in styles.css (comments
stripped)."""
for sel in ALL_LAYERS:
assert "filter" not in _rule_block(_css(), sel), (
f"{sel} must not use any filter"
)
assert "blur" not in _css_no_comments(), (
"no filter: blur anywhere in styles.css (phase-08 perf anchor)"
)