improvise/web/tests/shell.test.js

// What the page decides between the boundaries: transport selection, the two
// status facts, the watchdog and the extent arithmetic. No DOM is involved.

import { test } from "node:test";
import assert from "node:assert/strict";

import {
  composeStatus,
  createShell,
  extentOf,
  frameCostOf,
  indicator,
  socketUrl,
} from "../shell.js";

test("a bare peer takes the page's own scheme, and https never falls back", () => {
  assert.equal(socketUrl("127.0.0.1:8787", "http:"), "ws://127.0.0.1:8787");
  assert.equal(socketUrl("example.test", "https:"), "wss://example.test");
  // An explicit `ws://` on an https page is UPGRADED, not honoured: the
  // browser would refuse the mixed-content connection either way.
  assert.equal(socketUrl("ws://example.test", "https:"), "wss://example.test");
  assert.equal(socketUrl("ws://example.test", "http:"), "ws://example.test");
  // `wss://` is honoured on both, and the match is case-insensitive.
  assert.equal(socketUrl("WSS://example.test", "http:"), "WSS://example.test");
});

test("a peer whose host merely starts with ws is not a scheme", () => {
  assert.equal(socketUrl("wsserver.test:9000", "http:"), "ws://wsserver.test:9000");
});

test("the two status facts compose, and neither can erase the other", () => {
  assert.equal(composeStatus("connected", "Filter: Product = Latte"), "connected · Filter: Product = Latte");
  // An empty fact contributes nothing rather than a stray separator.
  assert.equal(composeStatus("connected", ""), "connected");
  assert.equal(composeStatus("", "saved"), "saved");
  assert.equal(composeStatus("", ""), "");
});

test("a repaint's model status does not overwrite a connection failure", () => {
  const seen = [];
  const shell = createShell({ onStatus: (t) => seen.push(t), timeoutMs: 10 });
  shell.fail("cannot reach 127.0.0.1:8787");
  shell.setModel("Filter: Product = Latte");
  assert.equal(seen.at(-1), "cannot reach 127.0.0.1:8787 · Filter: Product = Latte");
});

/// A clock the test drives, so the watchdog's arming is asserted rather than
/// waited for. `fire()` runs what is pending, as the event loop would.
function fakeClock() {
  let next = 1;
  const pending = new Map();
  return {
    setTimer: (fn) => {
      const id = next++;
      pending.set(id, fn);
      return id;
    },
    clearTimer: (id) => pending.delete(id),
    fire: () => {
      const due = [...pending.values()];
      pending.clear();
      for (const fn of due) fn();
    },
    count: () => pending.size,
  };
}

test("the watchdog speaks when the peer never answers the handshake", () => {
  const clock = fakeClock();
  const seen = [];
  const shell = createShell({
    onStatus: (t) => seen.push(t),
    timeoutMs: 8000,
    setTimer: clock.setTimer,
    clearTimer: clock.clearTimer,
  });
  shell.setShell("connecting…");
  shell.arm("sent no document");
  assert.equal(shell.armed(), true);
  clock.fire();
  assert.equal(seen.at(-1), "sent no document");
});

test("a loud failure DISARMS the watchdog rather than being replaced by it", () => {
  const clock = fakeClock();
  const seen = [];
  const shell = createShell({
    onStatus: (t) => seen.push(t),
    timeoutMs: 8000,
    setTimer: clock.setTimer,
    clearTimer: clock.clearTimer,
  });
  shell.arm("sent no document");
  shell.fail("disconnected");
  assert.equal(shell.armed(), false);
  assert.equal(clock.count(), 0);
  clock.fire();
  // The precise message is what stands, eight seconds later and forever.
  assert.equal(seen.at(-1), "disconnected");
});

test("a frame that arrives is the answer the watchdog was waiting for", () => {
  const clock = fakeClock();
  const seen = [];
  const shell = createShell({
    onStatus: (t) => seen.push(t),
    timeoutMs: 8000,
    setTimer: clock.setTimer,
    clearTimer: clock.clearTimer,
  });
  shell.setShell("connected");
  shell.arm("sent no document");
  shell.sawFrame();
  clock.fire();
  assert.equal(seen.at(-1), "connected");
});

test("arming twice leaves one timer, not two", () => {
  const clock = fakeClock();
  const shell = createShell({
    onStatus: () => {},
    timeoutMs: 8000,
    setTimer: clock.setTimer,
    clearTimer: clock.clearTimer,
  });
  shell.arm("first");
  shell.arm("second");
  assert.equal(clock.count(), 1);
});

test("the frame is charged for before the extent is announced", () => {
  // 10 rows and 4 columns fit; one header level and one row-label column are
  // not data, so the peer is asked for 9 by 3.
  const box = { height: 10 * 26, width: 4 * 110 };
  assert.deepEqual(extentOf(box, { rows: 1, cols: 1 }), { rows: 9, cols: 3 });
});

test("a window smaller than its own frame still asks for one cell", () => {
  assert.deepEqual(extentOf({ height: 0, width: 0 }, { rows: 3, cols: 2 }), {
    rows: 1,
    cols: 1,
  });
});

test("the frame costs a line per column level, plus one for a group line", () => {
  const model = (levels, groups, rowLevels) => ({
    col_levels: levels,
    col_groups: groups,
    row_levels: rowLevels,
  });
  assert.deepEqual(frameCostOf(model([["a"]], [], 1)), { rows: 1, cols: 1 });
  // Two category levels on the column axis, and a group line above them.
  assert.deepEqual(frameCostOf(model([["a"], ["b"]], [{ span: 1 }], 2)), {
    rows: 3,
    cols: 2,
  });
});

test("the collapse glyph points right when collapsed", () => {
  assert.equal(indicator(true), "▶");
  assert.equal(indicator(false), "▼");
});