Sending on-chain from Spending states the fee and minimum up front.

The form asks the ASP for a co-operative offboard quote (mining share +
service fee, minimum = fee + dust) for the address on screen, disables
Send for a balance below it and points to Lightning. A too-small amount
reads in words instead of the manager's internal error, and the
unilateral-exit note only appears when co-operation actually failed.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01VP5Ljqk7EYcm5QQAbzDwog

1 files changed, 102 insertions, 0 deletions

diff --git a/tools/ark/offboard-minimum-test.js b/tools/ark/offboard-minimum-test.js
new file mode 100644
index 0000000..9593089
--- /dev/null
+++ b/tools/ark/offboard-minimum-test.js
@@ -0,0 +1,102 @@
+// The on-chain send from Spending states the co-operative fee and minimum up
+// front, refuses a balance below it in words, and keeps the unilateral-exit
+// note for when the ASP actually failed to co-operate. Local manager stub.
+// Run: bun tools/ark/offboard-minimum-test.js
+import assert from 'node:assert/strict';
+import puppeteer from 'puppeteer-core';
+import { generateMnemonic } from '@scure/bip39';
+import { wordlist } from '@scure/bip39/wordlists/english';
+
+const bundle = await Bun.build({ entrypoints: ['src/app.js'], target: 'browser', minify: true,
+  plugins: [{ name: 'cooperative-exit-test', setup(build) {
+    build.onLoad({ filter: /src\/app\.js$/ }, async ({ path }) => ({ loader: 'js', contents: await Bun.file(path).text() + `
+window.coopApp = { ui, wallet, ctx, render, enterWallet, get ready() { return !_bootDeciding; } };
+` }));
+    build.onLoad({ filter: /src\/features\/ark\.js$/ }, async ({ path }) => ({ loader: 'js', contents:
+      (await Bun.file(path).text()).replace("  return {\n    id: 'ark',", `
+  window.coopFeature = { setManager: (mgr) => { ark = mgr; }, offboard: doArkOffboard };
+  return {\n    id: 'ark',`) }));
+    build.onLoad({ filter: /src\/video-compress\.js$/ }, () => ({ loader: 'js', contents: 'export async function compressVideo(f) { return f; }' }));
+  } }] });
+assert(bundle.success, bundle.logs.join('\n'));
+const html = `<!doctype html><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><style>${await Bun.file('src/style.css').text()}</style><div id="app"></div><script type="module">${await bundle.outputs[0].text()}</script>`;
+const server = Bun.serve({ port: 0, fetch: (req) => new URL(req.url).pathname === '/'
+  ? new Response(html, { headers: { 'Content-Type': 'text/html' } }) : new Response(null, { status: 404 }) });
+const browser = await puppeteer.launch({ executablePath: '/usr/bin/google-chrome', headless: true, args: ['--no-sandbox'] });
+try {
+  const page = await browser.newPage(), errors = [];
+  page.on('pageerror', (e) => errors.push(e.message));
+  await page.setViewport({ width: 390, height: 844 });
+  const cdp = await page.createCDPSession();
+  await cdp.send('Network.enable');
+  await cdp.send('Network.setBlockedURLs', { urls: ['wss://*', 'ws://*'] });
+  await page.setRequestInterception(true);
+  page.on('request', (r) => r.url().startsWith(server.url.origin) || r.url().startsWith('data:') ? r.continue() : r.abort());
+  await page.evaluateOnNewDocument(() => {
+    localStorage.setItem('btc-wallet-network', 'regtest');
+    localStorage.setItem('btc-wallet-ark-provider:regtest', 'off');
+  });
+  await page.goto(server.url.href, { waitUntil: 'domcontentloaded' });
+  await page.waitForFunction(() => window.coopApp?.ready);
+  await page.evaluate(async (mn) => {
+    await coopApp.enterWallet(mn, '', { fresh: true, generated: true });
+    coopApp.ui.onb = null; localStorage.removeItem('btc-wallet-onb-step');
+    coopApp.wallet.scan = async () => {};
+    window.coopCalls = [];
+    window.coopManager = {
+      state: { vtxos: [{ id: 'coin-a', amountSat: 1000, state: 'spendable' }], actions: [], movements: [] },
+      async offboardQuote() { coopCalls.push({ type: 'quote' }); return { chainSat: 736, serviceSat: 204, totalSat: 940, minSat: 1270 }; },
+      info: { network: 'regtest' }, _tipH: 100,
+      vtxos() { return this.state.vtxos; },
+      _decoded() { throw new Error('no exit transaction fixture'); },
+      refreshFee() { return 0; }, unseenReceives() { return []; }, ackReceives() {},
+      address() { return 'test-ark-address'; },
+      async send(address, amount) { coopCalls.push({ type: 'split', address, amount }); throw new Error('unexpected split'); },
+      async startOffboard(spk, address, ids) {
+        coopCalls.push({ type: 'offboard', address, ids: ids || null });
+        throw window.coopFail || new Error('unexpected offboard');
+      },
+    };
+    coopFeature.setManager(coopManager);
+    coopApp.ui.screen = 'wallet'; coopApp.ui.tab = 'receive'; coopApp.render();
+  }, generateMnemonic(wordlist));
+  const open = async () => {
+    await page.evaluate(() => {
+      const { ui, render } = coopApp;
+      ui.arkOffboarded = null; ui.arkBusy = null; ui.arkError = ''; ui.arkCoopFailed = false;
+      ui.screen = 'wallet'; ui.tab = 'send';
+      ui.arkOffboardSend = { address: coopApp.wallet.derive(0, 1).address, amount: '' };
+      render();
+    });
+    await page.waitForSelector('input.mono-input');
+  };
+  const card = () => page.evaluate(() => {
+    const c = document.querySelector('input.mono-input').closest('.card');
+    return { uni: /trustless|didn’t cooperate/i.test(c.innerText), text: c.innerText, sendDisabled: c.querySelector('.btn-primary').disabled, err: c.querySelector('.notice.err')?.textContent || '' };
+  });
+  await open();
+  await page.waitForFunction(() => /Fee about/.test(document.querySelector('input.mono-input').closest('.card').innerText));
+  let c = await card();
+  assert.match(c.text, /Fee about 940 sats right now \(736 mining \+ 204 coinos\), so it needs at least 1,270 sats/);
+  assert.match(c.text, /Your 1,000 sats are below the 1,270-sat minimum/);
+  assert(c.sendDisabled, 'send is off below the minimum');
+  assert(!c.uni, 'no unilateral-exit talk for a balance that is merely small');
+  console.log('✓ the co-operative fee and minimum show before any tap; a balance below it disables Send and points to Lightning');
+
+  // the manager's own guard (fees moved since the quote): plain words, no fallback
+  await page.evaluate(() => { window.coopFail = Object.assign(new Error('ark balance too small to offboard after fees'), { tooSmall: true, feeSat: 950, minSat: 1280 }); });
+  await page.evaluate(() => coopFeature.offboard(0, coopApp.wallet.derive(0, 1).address));
+  c = await card();
+  assert.equal(c.err, 'Sending on-chain needs at least 1,280 sats right now (the fee is about 950).');
+  assert(!c.uni && !/ark balance too small/.test(c.text));
+  console.log('✓ a too-small offboard reads in words and does not offer the unilateral exit');
+
+  // the ASP refusing is what the unilateral exit is for
+  await page.evaluate(() => { window.coopFail = new Error('server unavailable'); });
+  await page.evaluate(() => coopFeature.offboard(0, coopApp.wallet.derive(0, 1).address));
+  c = await card();
+  assert.equal(c.err, 'server unavailable');
+  assert(c.uni, 'a failed co-operation still explains the unilateral exit: ' + c.text);
+  console.log('✓ a failed co-operation still shows the unilateral-exit note');
+  assert.deepEqual(errors, []);
+} finally { await browser.close(); server.stop(true); }