Files
wickra/bindings/python/tests/test_streaming_vs_batch.py
T
kingchenc 5867f71450 feat: trade-flow microstructure indicators (part 2 of 4) (#113)
* feat(core): add 3 trade-flow microstructure indicators

SignedVolume (per-trade size signed by aggressor), CumulativeVolumeDelta
(running signed-volume total), and TradeImbalance (rolling buy/sell volume
imbalance over a trade window). All consume the Trade type, with full unit
coverage. Extends the Microstructure family.

* feat(bindings): expose trade-flow microstructure indicators

Python, Node and WASM bindings for SignedVolume, CumulativeVolumeDelta and
TradeImbalance. Each takes a trade via update(price, size, is_buy); Python and
Node expose a batch over three parallel arrays, WASM exposes per-trade update.
Regenerates node index.d.ts/.js.

* test(bindings,fuzz,bench): cover trade-flow microstructure indicators

Python and Node: reference values, streaming-vs-batch, lifecycle/repr and input
validation (zero window, negative size, non-positive price, mismatched batch
lengths). New indicator_update_trade fuzz target. Synthetic trade-tape benches
(signed_volume cheapest, trade_imbalance windowed/expensive).

* docs: add trade-flow indicators + bump counter to 227

README Microstructure family row gains signed volume / CVD / trade imbalance and
the counter goes 224 -> 227; CHANGELOG records the trade-flow indicators.
2026-06-01 16:38:48 +02:00

234 lines
7.6 KiB
Python

"""For every indicator, batch(prices) must equal repeated update(price).
This is the central correctness contract of Wickra: the two APIs share one
implementation, so they cannot disagree. These tests verify it from Python
across the entire warmup → steady-state transition.
"""
from __future__ import annotations
import math
import numpy as np
import pytest
import wickra as ta
def _equal_with_nan(a: np.ndarray, b: np.ndarray, tol: float = 1e-9) -> bool:
"""NumPy ``==`` treats NaN as not-equal; emulate ``equal_nan`` for floats."""
if a.shape != b.shape:
return False
both_nan = np.isnan(a) & np.isnan(b)
diff_ok = np.where(both_nan, 0.0, np.abs(a - b))
return bool(np.all(diff_ok <= tol))
@pytest.mark.parametrize(
"cls, args",
[
(ta.SMA, (14,)),
(ta.EMA, (14,)),
(ta.WMA, (14,)),
(ta.RSI, (14,)),
],
)
def test_scalar_streaming_matches_batch(cls, args, sine_prices):
batch = cls(*args).batch(sine_prices)
streamer = cls(*args)
streamed = np.array(
[streamer.update(float(p)) if streamer is not None else None for p in sine_prices],
dtype=object,
)
# Map None -> NaN to compare against batch.
streamed = np.array(
[math.nan if v is None else float(v) for v in streamed], dtype=np.float64
)
assert _equal_with_nan(batch, streamed)
def test_macd_streaming_matches_batch(sine_prices):
batch = ta.MACD().batch(sine_prices)
streamer = ta.MACD()
rows = []
for p in sine_prices:
v = streamer.update(float(p))
if v is None:
rows.append([math.nan, math.nan, math.nan])
else:
rows.append(list(v))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_bollinger_streaming_matches_batch(sine_prices):
batch = ta.BollingerBands().batch(sine_prices)
streamer = ta.BollingerBands()
rows = []
for p in sine_prices:
v = streamer.update(float(p))
if v is None:
rows.append([math.nan, math.nan, math.nan, math.nan])
else:
rows.append(list(v))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_atr_streaming_matches_batch(ohlc_series):
high, low, close = ohlc_series
batch = ta.ATR(14).batch(high, low, close)
streamer = ta.ATR(14)
rows = []
for h, l, c in zip(high, low, close):
rows.append(streamer.update((float(c), float(h), float(l), float(c), 0.0, 0)))
streamed = np.array([math.nan if v is None else v for v in rows], dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_stochastic_streaming_matches_batch(ohlc_series):
high, low, close = ohlc_series
batch = ta.Stochastic(14, 3).batch(high, low, close)
streamer = ta.Stochastic(14, 3)
rows = []
for h, l, c in zip(high, low, close):
v = streamer.update((float(c), float(h), float(l), float(c), 0.0, 0))
rows.append([math.nan, math.nan] if v is None else list(v))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_obv_streaming_matches_batch(ohlc_series):
_, _, close = ohlc_series
volume = np.ones_like(close)
batch = ta.OBV().batch(close, volume)
streamer = ta.OBV()
rows = []
for c, v in zip(close, volume):
rows.append(streamer.update((float(c), float(c), float(c), float(c), float(v), 0)))
streamed = np.array([math.nan if x is None else x for x in rows], dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_mama_streaming_matches_batch(sine_prices):
batch = ta.MAMA().batch(sine_prices)
streamer = ta.MAMA()
rows = []
for p in sine_prices:
v = streamer.update(float(p))
if v is None:
rows.append([math.nan, math.nan])
else:
rows.append(list(v))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_super_smoother_streaming_matches_batch(sine_prices):
batch = ta.SuperSmoother(10).batch(sine_prices)
streamer = ta.SuperSmoother(10)
streamed = np.array(
[math.nan if (v := streamer.update(float(p))) is None else float(v) for p in sine_prices],
dtype=np.float64,
)
assert _equal_with_nan(batch, streamed)
def test_rolling_vwap_streaming_matches_batch(ohlc_series):
# RollingVWAP(20) on the shared OHLC series. Provides finite-memory VWAP
# parity coverage now that the indicator is exposed across all bindings.
high, low, close = ohlc_series
volume = np.linspace(100.0, 200.0, num=close.size, dtype=np.float64)
batch = ta.RollingVWAP(20).batch(high, low, close, volume)
streamer = ta.RollingVWAP(20)
rows = []
for h, l, c, v in zip(high, low, close, volume):
rows.append(streamer.update((float(c), float(h), float(l), float(c), float(v), 0)))
streamed = np.array([math.nan if x is None else x for x in rows], dtype=np.float64)
assert _equal_with_nan(batch, streamed)
assert streamer.period == 20
assert streamer.warmup_period() == 20
assert streamer.is_ready()
streamer.reset()
assert not streamer.is_ready()
def test_value_area_streaming_matches_batch(ohlc_series):
high, low, close = ohlc_series
volume = np.linspace(100.0, 200.0, num=close.size, dtype=np.float64)
batch = ta.ValueArea(20, 50, 0.70).batch(high, low, volume)
streamer = ta.ValueArea(20, 50, 0.70)
rows = []
for h, l, v in zip(high, low, volume):
mid = float((h + l) / 2.0)
out = streamer.update((mid, float(h), float(l), mid, float(v), 0))
rows.append([math.nan, math.nan, math.nan] if out is None else list(out))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_initial_balance_streaming_matches_batch(ohlc_series):
high, low, _close = ohlc_series
batch = ta.InitialBalance(12).batch(high, low)
streamer = ta.InitialBalance(12)
rows = []
for h, l in zip(high, low):
mid = float((h + l) / 2.0)
out = streamer.update((mid, float(h), float(l), mid, 0.0, 0))
rows.append([math.nan, math.nan] if out is None else list(out))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_opening_range_streaming_matches_batch(ohlc_series):
high, low, close = ohlc_series
batch = ta.OpeningRange(6).batch(high, low, close)
streamer = ta.OpeningRange(6)
rows = []
for h, l, c in zip(high, low, close):
out = streamer.update((float(c), float(h), float(l), float(c), 0.0, 0))
rows.append([math.nan, math.nan, math.nan] if out is None else list(out))
streamed = np.array(rows, dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_orderbook_streaming_matches_batch():
snaps = [
(
[100.0, 99.0],
[1.0 + (i % 5), 1.0],
[101.0, 102.0],
[1.0 + ((i + 1) % 3), 1.0],
)
for i in range(30)
]
batch = ta.Microprice().batch(snaps)
streamer = ta.Microprice()
streamed = np.array([streamer.update(*snap) for snap in snaps], dtype=np.float64)
assert _equal_with_nan(batch, streamed)
def test_tradeflow_streaming_matches_batch():
n = 30
price = np.full(n, 100.0)
size = np.array([1.0 + (i % 4) for i in range(n)], dtype=np.float64)
is_buy = [i % 3 != 0 for i in range(n)]
batch = ta.CumulativeVolumeDelta().batch(price, size, is_buy)
streamer = ta.CumulativeVolumeDelta()
streamed = np.array(
[streamer.update(price[i], size[i], is_buy[i]) for i in range(n)],
dtype=np.float64,
)
assert _equal_with_nan(batch, streamed)