mirror of
https://github.com/priyanshujain/sanderling.git
synced 2026-10-02 11:07:10 +00:00
pj
45b7624280
json has no undefined, so an extractor whose getter returned one had its
whole index dropped by JSON.stringify. that index then kept goja's
dump-derived value while its neighbours held the page's, and a property
comparing previous to current across the split fires on a healthy app.
folio has nine on(route, tag) extractors, so this was most extractors on
most steps.
each reading is wrapped in a {value} envelope: the drop now happens
inside the entry, and an absent value means the getter returned
undefined, which is what the goja host records for the same getter. a
json null would instead claim it returned null and x.current ===
undefined would answer differently on the two hosts.
sanderling
Autonomous property-based testing for mobile and web apps.
You write rules that must always hold about your app. sanderling explores the app on its own for minutes or hours, performing thousands of taps, swipes, and inputs, and records every step where a rule breaks. No scripted test paths. One TypeScript spec runs against Android, iOS, and web builds of the same app.
import { extract, always } from "@sanderling/spec";
import { defaultActions } from "@sanderling/spec/defaults";
import { noUncaughtExceptions } from "@sanderling/spec/defaults/properties";
const balance = extract("balance", s =>
parseInt(s.ax.find({ testTag: "Balance" })?.text ?? "0", 10));
export const properties = {
noUncaughtExceptions,
balanceNeverNegative: always(() => balance.current >= 0),
};
export const actionsRoot = defaultActions;
Every run produces a trace: one JSON line and one screenshot per step. sanderling replay opens it in a web UI for stepping through actions, screenshots, property timelines, and violations.
Alpha. Android, iOS, and web (Chrome driver only). Full scope in the v0.1.0 roadmap.
Docs
- Introduction: what property-based testing is and how sanderling works
- Case study: Folio: sanderling finding a real bug in a mobile app
- Getting started: install the CLI and run it against Folio
- Spec language reference
- Examples: folio (KMP, Android/iOS/web), folio-web (React + Vite)
- Architecture for contributors
sanderling, a wading bird that probes the shoreline for bugs that lie beneath.