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

pkg/spec/test/folio-new-account.test.ts

@@ -0,0 +1,235 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import { createdAccountHasNonZeroBalance } from "../../../examples/folio/sanderling/predicates.ts";
+
+const created = { kind: "Tap", on: "testTag:AddAccountScreen > testTag:AddAccountSubmit" };
+const idle = { kind: "Tap", on: "testTag:HomeScreen > testTag:AccountCard" };
+
+const account = (name: string, balance: number | null) => ({ name, balance });
+
+// The property still has teeth: the account the fuzzer just asked for, holding
+// money on the step its creation landed on Home, is a real violation.
+test("an account created holding money is a violation", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    true,
+  );
+});
+
+test("a double-tapped create is judged the same way", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: { kind: "DoubleTap", on: "id:AddAccountSubmit" },
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    true,
+  );
+});
+
+test("an account created empty is what the app is supposed to do", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 0)],
+    }),
+    false,
+  );
+});
+
+test("a balance that could not be read is not evidence", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", null)],
+    }),
+    false,
+  );
+});
+
+// The false positives this replaces. Home lists the accounts that fit the
+// viewport, so an account arrives in a later reading for reasons that have
+// nothing to do with being created: the list scrolled, a clipped card finished
+// laying out, or (before the route fix) the earlier reading came off a
+// half-rendered Home mid-transition. Measured on android: an existing Travel
+// holding $24,112.00 and an existing Savings holding $429,585.00, convicted for
+// coming into view.
+test("an account scrolling into view is not an account being created", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: idle,
+      typedName: "Travel",
+      before: [account("Emergency Fund", 461012300), account("Checking", 0)],
+      after: [
+        account("Emergency Fund", 461012300),
+        account("Checking", 0),
+        account("Travel", 2411200),
+        account("Savings", 0),
+      ],
+    }),
+    false,
+  );
+});
+
+test("nor is one that appears with no action at all behind it", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: null,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 2411200)],
+    }),
+    false,
+  );
+});
+
+// Even on the creation step, the only card judged is the one that answers to
+// the name the fuzzer typed. A card that came into view alongside it is still
+// just a card that came into view.
+test("a funded account arriving beside the created one is not judged", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Savings",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Savings", 0), account("Travel", 2411200)],
+    }),
+    false,
+  );
+});
+
+test("off Home there is no reading to judge", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "ledger",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    false,
+  );
+});
+
+test("a transition frame names no route, so nothing is judged there either", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: null,
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    false,
+  );
+});
+
+test("an unknown reading on either side is not evidence", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: null,
+      after: [account("Travel", 5000)],
+    }),
+    false,
+  );
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: null,
+    }),
+    false,
+  );
+});
+
+// defaultActions types edge-case text into the name field, and an empty name is
+// not a name we can find a card by.
+test("an empty typed name attributes nothing", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "   ",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    false,
+  );
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: undefined,
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000)],
+    }),
+    false,
+  );
+});
+
+// Web merges the card into one node whose text opens with the avatar initials,
+// so the identity key carries them: "TRTravel" is the card for "Travel".
+test("the merged web key still matches the name that was typed", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("CHChecking", 0)],
+      after: [account("CHChecking", 0), account("TRTravel", 5000)],
+    }),
+    true,
+  );
+});
+
+// Two cards answering to one typed name leave the appearance unattributable:
+// the fuzzer creates duplicates from a five-name list, and the tree has been
+// seen exposing the same card twice on a transition frame.
+test("two cards matching the typed name are not attributable to the creation", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0)],
+      after: [account("Checking", 0), account("Travel", 5000), account("MyTravel", 900)],
+    }),
+    false,
+  );
+});
+
+test("a card that was already there is not a card that was just created", () => {
+  assert.equal(
+    createdAccountHasNonZeroBalance({
+      route: "home",
+      lastAction: created,
+      typedName: "Travel",
+      before: [account("Checking", 0), account("Travel", 2411200)],
+      after: [account("Checking", 0), account("Travel", 2411200)],
+    }),
+    false,
+  );
+});