TRIMSP/tests/recoil-cutoff-test.js

// Checks the GUI handling of the parIRL/parERC combination that used to crash
// the engine. A zero recoil cutoff makes the transport cascade diverge, so the
// GUI supplies a cutoff when recoils are switched on and refuses the run if the
// user insists on the zero cutoff.
//
// The real functions are lifted out of TrimSPlib.js and run against a minimal
// document stub, so this exercises shipped code rather than a copy of it.
// Run with: node tests/recoil-cutoff-test.js

const fs = require('fs');
const path = require('path');

const libPath = path.join(__dirname, '..', 'TrimSPlib.js');
const src = fs.readFileSync(libPath, 'utf8');

function grab(re) {
  const m = src.match(re);
  if (!m) {
    throw new Error('pattern not found in ' + libPath + ': ' + re);
  }
  return m[0];
}

const fields = {};
let shown = [];
let statusMsg = null;

global.document = {
  getElementById(id) {
    if (!(id in fields)) {
      fields[id] = { value: '', focus() { this.focused = true; } };
    }
    return fields[id];
  }
};
global.showTransientWarning = (message) => { shown.push(message); };
global.updateStatusBar = (options) => {
  if (options && options.run) { statusMsg = options.run; }
};

eval([
  grab(/var TRIMSP_MIN_RECOIL_CUTOFF = [\d.]+;/),
  grab(/function recoilCutoffIsUnusable\(\) \{[\s\S]*?\n\}/),
  grab(/function handleRecoilModeChange\(\) \{[\s\S]*?\n\}/),
].join('\n\n'));

// The pre-run refusal, lifted verbatim out of runSimulationSequence. It keeps
// that function's return convention, where 0 means "aborted before the engine
// was invoked" and 1 means the run may proceed.
eval('function runGuardVerdict() {\n'
  + grab(/    if \(recoilCutoffIsUnusable\(\)\) \{[\s\S]*?\n    \}\n/)
  + '  return 1;\n}\n');

function reset(irl, erc) {
  for (const key of Object.keys(fields)) { delete fields[key]; }
  const makeField = (value) => ({
    value: value,
    focus() { this.focused = true; },
  });
  fields.parIRL = makeField(String(irl));
  fields.parERC = makeField(String(erc));
  shown = [];
  statusMsg = null;
}

const cases = [
  // description,                  IRL,  ERC,     touchIRL, fills,  refuses
  ['default GUI state',              0, '0.0',   false,    false, false],
  ['parIRL 0->1, parERC=0 default',  1, '0.0',   true,     true,  false],
  ['user insists, edits parERC=0',   1, '0',     false,    false, true],
  ['user sets parERC back to 0',     1, '0.0',   false,    false, true],
  ['valid parIRL=1 with cutoff',     1, '0.02',  false,    false, false],
  ['parIRL 0->1, cutoff already set', 1, '0.02', true,     false, false],
  ['valid parIRL=1, large cutoff',   1, '15',    false,    false, false],
  ['parIRL=0 with parERC=0',         0, '0.0',   false,    false, false],
  ['parIRL 0->1, negative parERC',   1, '-1',    true,     true,  false],
  ['parIRL 0->1, blank parERC',      1, '',      true,     true,  false],
  ['parIRL 0->1, non-numeric parERC', 1, 'abc',  true,     true,  false],
  ['non-numeric parIRL treated as off', 'x', '0.0', true, false, false],
];

let passed = 0;
let failed = 0;

for (const [name, irl, erc, touchIRL, expectFilled, expectRefused] of cases) {
  reset(irl, erc);
  const before = fields.parERC.value;
  // The handler is wired to the parIRL widget only, so it runs when the user
  // changes parIRL and not when they go back and retype the cutoff themselves.
  if (touchIRL) { handleRecoilModeChange(); }
  const filled = fields.parERC.value !== before;
  const refused = runGuardVerdict() === 0;
  const refusedOk = (refused === expectRefused);
  // A refused run must actually say something in both places.
  const explained = !refused
    || (shown.length > 0 && typeof statusMsg === 'string' && statusMsg.length > 0);

  const ok = (filled === expectFilled) && refusedOk && explained;
  if (ok) { passed++; } else { failed++; }
  console.log((ok ? 'PASS  ' : 'FAIL  ') + name.padEnd(34)
    + 'parERC=' + String(fields.parERC.value).padEnd(6)
    + (filled ? 'filled in' : 'left alone').padEnd(13)
    + (refused ? 'refused' : 'runs')
    + (shown.length ? '  | "' + shown[shown.length - 1] + '"' : ''));
}

console.log('\n' + passed + ' passed, ' + failed + ' failed');
process.exit(failed ? 1 : 0);