test(folio): cover transition frames, card readings and creation

pkg/spec/test/folio-transition-frame.test.ts

@@ -0,0 +1,142 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import {
+  countSubmitsInWindow,
+  readHomeCards,
+  readHomeTotalBalance,
+  routeOfFrame,
+  submitChangesBalanceByTypedAmount,
+} from "../../../examples/folio/sanderling/predicates.ts";
+
+// The spec's own screen table. A frame is the set of markers its accessibility
+// tree carries, which is all routeOfFrame is allowed to look at.
+const SCREENS = {
+  login: "LoginScreen",
+  "add-account": "AddAccountScreen",
+  "add-transaction": "AddTransactionScreen",
+  ledger: "LedgerScreen",
+  home: "HomeScreen",
+};
+
+const frame =
+  (...tags: string[]) =>
+  (tag: string) =>
+    tags.includes(tag);
+
+test("a frame showing one screen names its route", () => {
+  assert.equal(routeOfFrame(SCREENS, frame("LoginScreen")), "login");
+  assert.equal(routeOfFrame(SCREENS, frame("AddAccountScreen")), "add-account");
+  assert.equal(routeOfFrame(SCREENS, frame("AddTransactionScreen")), "add-transaction");
+  assert.equal(routeOfFrame(SCREENS, frame("LedgerScreen")), "ledger");
+  assert.equal(routeOfFrame(SCREENS, frame("HomeScreen")), "home");
+});
+
+test("a frame showing no screen at all is unknown", () => {
+  assert.equal(routeOfFrame(SCREENS, frame()), null);
+  assert.equal(routeOfFrame(SCREENS, frame("SomethingElse")), null);
+});
+
+// The android transition frame: 425 of 1879 steps across 17 measured runs carry
+// two screens, in every combination the navigation graph allows. Ranking the
+// markers and taking the first answers add-transaction for the first of these
+// while a second, unscoped look answers "on Home" -- and two answers for one
+// frame is the defect. There is one answer now, and on a transition frame it is
+// "I do not know".
+test("a transition frame showing two screens names neither", () => {
+  assert.equal(routeOfFrame(SCREENS, frame("AddTransactionScreen", "HomeScreen")), null);
+  assert.equal(routeOfFrame(SCREENS, frame("HomeScreen", "LedgerScreen")), null);
+  assert.equal(routeOfFrame(SCREENS, frame("AddAccountScreen", "HomeScreen")), null);
+  assert.equal(routeOfFrame(SCREENS, frame("HomeScreen", "LoginScreen")), null);
+  assert.equal(routeOfFrame(SCREENS, frame("AddTransactionScreen", "LedgerScreen")), null);
+});
+
+test("the three-screen frames android also emits name nothing", () => {
+  assert.equal(
+    routeOfFrame(SCREENS, frame("AddTransactionScreen", "HomeScreen", "LedgerScreen")),
+    null,
+  );
+});
+
+// Everything read off Home takes the route as its only input, so a frame that
+// is not Home cannot be read as Home by anything.
+test("a transition frame's half-drawn Home total is not a reading", () => {
+  const route = routeOfFrame(SCREENS, frame("AddTransactionScreen", "HomeScreen"));
+  assert.deepEqual(
+    readHomeTotalBalance({ route, totalText: "$86,911.00", previousCarrier: 8681600 }),
+    { value: 8681600, carrier: 8681600, fresh: false },
+  );
+});
+
+test("nor is its half-drawn card list", () => {
+  const route = routeOfFrame(SCREENS, frame("AddAccountScreen", "HomeScreen"));
+  const carried = { Travel: "8", Checking: "0" };
+  const partial = { Travel: "8" };
+  assert.deepEqual(readHomeCards<Record<string, string>>({ route, reading: partial, previousCarrier: carried }), {
+    value: carried,
+    carrier: carried,
+    fresh: false,
+  });
+});
+
+// The false conviction itself, android seed 3, steps 98-102 of the recorded
+// trace. Five submits deep into the window the app sits on AddTransaction with
+// "339" typed; a double-tap on Back starts the trip Home; the frame that comes
+// back carries BOTH screens with Home's total already drawn behind the outgoing
+// one. The old spec read that total as a fresh Home reading, reset the window to
+// zero, and aimed the next tap at a TxnSubmit button that had stopped existing.
+// The tap landed on Home, committed nothing, and the property demanded 33900 of
+// movement for it. Nine of the eleven android convictions were this, all at
+// delta 0.0x, all a single Tap where the real bug is a DoubleTap.
+test("the measured android transition chain no longer convicts at delta 0", () => {
+  let carrier: number | null = 8681600;
+  let submits = 5;
+  const step = (
+    tags: string[],
+    totalText: string | undefined,
+    lastAction: { kind: string; on: string } | null,
+  ) => {
+    const route = routeOfFrame(SCREENS, frame(...tags));
+    const reading = readHomeTotalBalance({ route, totalText, previousCarrier: carrier });
+    const window = countSubmitsInWindow({ previousCount: submits, lastAction, fresh: reading.fresh });
+    carrier = reading.carrier;
+    submits = window.next;
+    return { route, total: reading.value, submits: window.reported };
+  };
+
+  const back = { kind: "DoubleTap", on: "id:BackButton" };
+  const phantomSubmit = { kind: "Tap", on: "testTag:AddTransactionScreen > testTag:TxnSubmit" };
+
+  const transition = step(["AddTransactionScreen", "HomeScreen"], "$86,911.00", back);
+  assert.equal(transition.route, null);
+  assert.equal(transition.total, 8681600);
+  assert.equal(transition.submits, 5);
+
+  const landing = step(["HomeScreen"], "$86,911.00", phantomSubmit);
+  assert.equal(landing.submits, 6);
+  assert.equal(
+    submitChangesBalanceByTypedAmount({
+      route: landing.route,
+      lastAction: phantomSubmit,
+      submitsInWindow: landing.submits,
+      typedAmount: 33900,
+      prevTotalBalance: transition.total,
+      currTotalBalance: landing.total,
+    }),
+    true,
+  );
+
+  // What the reset bought the old spec: the same landing, judged against a
+  // window of one and a total the transition frame had already banked.
+  assert.equal(
+    submitChangesBalanceByTypedAmount({
+      route: "home",
+      lastAction: phantomSubmit,
+      submitsInWindow: 1,
+      typedAmount: 33900,
+      prevTotalBalance: 8691100,
+      currTotalBalance: 8691100,
+    }),
+    false,
+  );
+});