Files

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kingchenc 53941b7b07 feat: add Market Breadth family with CrossSection input (#153 )

## What

Adds a new indicator input type and family for **market-breadth** analysis — indicators that aggregate the state of an entire universe of symbols at each tick, rather than a single instrument's price. This is the last open input-type on the expansion roadmap (S10) and unblocks the remaining breadth indicators (McClellan, TRIN, High-Low Index, ...).

## Core

- **`CrossSection` input type** (`crates/wickra-core/src/cross_section.rs`) — one tick carrying the per-symbol state of the whole universe as a `Vec<Member>` + `timestamp`. Each `Member` precomputes a signed `change` (sign classifies advancing / declining / unchanged), a `volume`, and `new_high` / `new_low` extreme flags, so the breadth indicators stay stateless per tick. Both `Member` and `CrossSection` are `#[non_exhaustive]` for additive field growth. `CrossSection::new` validates the universe (non-empty, finite changes, finite non-negative volumes); `new_unchecked` skips validation for hot paths. `advancers()` / `decliners()` count by sign.
- **`Error::InvalidCrossSection`** variant for the validation failures.
- **`AdvanceDecline`** (`advance_decline.rs`) — the Advance/Decline Line: the running cumulative sum of net advancing-minus-declining issues. `Input = CrossSection`, `Output = f64`, ready after the first tick.
- New **"Market Breadth"** `FAMILIES` group; indicator count **314 → 315**, family count nineteen → twenty.

## Bindings

All custom (CrossSection is non-scalar, so no macros apply). The universe crosses each boundary as parallel arrays (`change`, `volume`, `new_high`, `new_low`):
- **Python / Node** expose `update` + `batch` (one array group per tick). Node satisfies the completeness contract (`update`/`batch`/`reset`/`isReady`/`warmupPeriod`).
- **WASM** exposes only `update` (the universe is ragged across ticks, matching the other multi-input wasm indicators) with numeric high/low flags.
- Python `map_err` gains the new error arm; `__init__.py` gets a `# Market Breadth` section in both the import and `__all__` blocks. `index.d.ts` / `index.js` regenerated.

## Tests / Fuzz

- Dedicated **streaming-vs-batch + reference-value + ragged-rejection** tests in Python (`test_new_indicators.py`) and Node (`indicators.test.js`) — kept out of the scalar/candle parametrize lists.
- Rust unit tests cover every reject branch (empty / non-finite change / negative & non-finite volume) and every indicator branch.
- New fuzz target `indicator_update_crosssection` drives `AdvanceDecline` over bounded ragged universes built with `new_unchecked`.

## Verify

- `cargo fmt --all` clean
- `cargo test -p wickra-core --lib` → 2593 passed; `--doc` → 298 passed
- `cargo clippy --workspace --all-targets --all-features -- -D warnings` clean
- `cd bindings/node && npm run build && npm test` → 398 passed
- `maturin develop --release` + `pytest bindings/python/tests` → all passed
- counter check: mod-count 315 == lib-block 315

2026-06-03 04:11:10 +02:00

fuzz_targets

feat: add Market Breadth family with CrossSection input (#153 )

2026-06-03 04:11:10 +02:00

.gitignore

E16: add a cargo-fuzz harness

2026-05-22 16:44:19 +02:00

Cargo.toml

feat: add Market Breadth family with CrossSection input (#153 )

2026-06-03 04:11:10 +02:00

README.md

test(fuzz): cover every indicator, scalar and candle inputs (R9)

2026-05-23 10:33:05 +02:00

README.md

Fuzzing Wickra

cargo-fuzz harnesses for the parsing and stateful entry points of Wickra. Fuzzing requires a nightly Rust toolchain.

Setup

cargo install cargo-fuzz
rustup toolchain install nightly

Targets

Target	What it exercises
`csv_reader`	`CandleReader` over arbitrary bytes — headers, cells, BOM, binary noise.
`binance_envelope`	`RawWsEnvelope` deserialization from arbitrary strings.
`indicator_update`	Every scalar-input indicator (SMA / EMA / WMA / RSI / DEMA / TEMA / HMA / ROC / TRIX / SMMA / TRIMA / ZLEMA / KAMA / T3 / MOM / CMO / TSI / PMO / StochRSI / DPO / PPO / Coppock / StdDev / UlcerIndex / HistoricalVolatility / LinearRegression / LinRegSlope / LinRegAngle / VHF / ZScore / MACD / Bollinger) streamed + batched over arbitrary `f64` sequences (NaN, ±inf, jumps).
`indicator_update_candle`	Every candle-input indicator (ATR, NATR, TrueRange, ChaikinVolatility, Keltner, Donchian, PSAR, SuperTrend, ChandelierExit, ChandeKrollStop, ATRTrailingStop, ADX, Aroon, AroonOscillator, Vortex, MassIndex, ChoppinessIndex, CCI, WilliamsR, AwesomeOscillator, AcceleratorOscillator, UltimateOscillator, BalanceOfPower, OBV, MFI, VWAP, RollingVWAP, VWMA, ADL, VPT, CMF, ChaikinOscillator, ForceIndex, EaseOfMovement, TypicalPrice, MedianPrice, WeightedClose, Stochastic) streamed + batched over fuzz-derived OHLCV candles.
`tick_aggregator`	`TickAggregator` over arbitrary `(price, volume, timestamp)` triples.

Run

# From the repository root:
cargo +nightly fuzz run csv_reader
cargo +nightly fuzz run binance_envelope
cargo +nightly fuzz run indicator_update
cargo +nightly fuzz run indicator_update_candle
cargo +nightly fuzz run tick_aggregator

Each run continues until a crash is found or it is interrupted. A short time-boxed smoke run is useful in CI:

cargo +nightly fuzz run csv_reader -- -max_total_time=60

The expectation for every target is that it never panics: malformed or adversarial input must surface as an Err, never a crash.