Point of sale: in a currency the pad works like a till — digits shift in from the right.

5 is 0.05, 277 is 2.77, 5588 is 55.88; backspace shifts out; the "." key
becomes "00". Sats are whole numbers and type plainly.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Tmfg8k5f3TbNJS34qiqHAp

2 files changed, 24 insertions, 3 deletions

diff --git a/src/features/pos.js b/src/features/pos.js
index 42e4590..127effc 100644
--- a/src/features/pos.js
+++ b/src/features/pos.js
@@ -45,10 +45,20 @@ export function posFeature(ctx) {
     render();
   }
   // Digits on screen, into the same field a keyboard or a paste would fill.
+  // In the user's currency the pad works like a till: digits shift in from
+  // the right with two decimals, so 5 is 0.05, 277 is 2.77, 5588 is 55.88,
+  // and the "." key becomes "00". Sats are whole numbers and type plainly.
   function numpad(get, set) {
+    const cents = getUnit() === 'fiat';
     const press = (k) => {
       let v = String(get() || '');
-      if (k === 'del') v = v.slice(0, -1);
+      if (cents) {
+        let d = v.replace(/\D/g, '');
+        if (k === 'del') d = d.slice(0, -1);
+        else d = (d + (k === '.' ? '00' : k)).slice(0, 12);
+        d = d.replace(/^0+/, '');
+        v = d ? (parseInt(d, 10) / 100).toFixed(2) : '';
+      } else if (k === 'del') v = v.slice(0, -1);
       else if (k === '.') { if (!v.includes('.')) v = (v || '0') + '.'; }
       else if (v === '0') v = k;
       else v += k;
@@ -57,7 +67,7 @@ export function posFeature(ctx) {
     const key = (k, label) => h('button', { class: 'pos-key' + (k === 'del' ? ' del' : ''), type: 'button', 'aria-label': k === 'del' ? t('posBackspace') : label, onClick: () => press(k) }, label);
     return h('div', { class: 'pos-pad' },
       ...['1', '2', '3', '4', '5', '6', '7', '8', '9'].map((k) => key(k, k)),
-      key('.', '.'), key('0', '0'), key('del', '\u232b'));
+      key('.', cents ? '00' : '.'), key('0', '0'), key('del', '\u232b'));
   }
   function close() {
     const p = ui.pos;
diff --git a/tools/pos-test.js b/tools/pos-test.js
index a50d9de..c38c3ea 100644
--- a/tools/pos-test.js
+++ b/tools/pos-test.js
@@ -16,7 +16,7 @@ const wallet = { loadFeatureState: (k, d) => (k in state ? state[k] : d), saveFe
 const ctx = {
   h, ui, wallet, render, toast: (m) => (window.toasts = (window.toasts || [])).push(m), copy: (x) => (window.copied = x),
   fmtAmount: (n) => Number(n).toLocaleString('en-US'), unitLabel: () => 'sats', unitTag: () => h('span', { class: 'unit-tag' }, 'sats'),
-  parseAmount: (v) => { const n = Number(String(v).replace(/,/g, '')); return isFinite(n) ? Math.round(n) : null; }, getUnit: () => 'sats',
+  parseAmount: (v) => { const n = Number(String(v).replace(/,/g, '')); return isFinite(n) ? Math.round(n) : null; }, getUnit: () => window.__unit || 'sats',
   brandHeader: () => null,
   hook(name, ...a) {
     if (name === 'arkReady') return true;
@@ -97,6 +97,17 @@ try {
   check('with the prompt off, Charge goes straight to the invoice', /Scan to pay/.test(await text()) && /300 sats/.test(await text()) && await page.evaluate(() => test.watch === 'ln3'));
   await page.evaluate(() => test.settle(false)); await pause(50);
   check('an expired invoice returns to the amount screen and says so', /That invoice expired/.test(await text()));
+  console.log('\n[a till in dollars]');
+  await page.evaluate(() => { window.__unit = 'fiat'; test.ui.pos = null; test.open(); }); await pause(50);
+  await click('5');
+  check('one digit is cents', await page.$eval('.pos-amount', (i) => i.value) === '0.05');
+  await click('\u232b'); for (const k of ['2', '7', '7']) await click(k);
+  check('digits shift in from the right', await page.$eval('.pos-amount', (i) => i.value) === '2.77');
+  await click('\u232b'); await click('\u232b'); await click('\u232b'); for (const k of ['5', '5', '8', '8']) await click(k);
+  check('...to any length', await page.$eval('.pos-amount', (i) => i.value) === '55.88');
+  await click('\u232b'); await click('\u232b'); await click('00');
+  check('the dot key is 00 in a currency', await page.$eval('.pos-amount', (i) => i.value) === '55.00');
+  await page.evaluate(() => { window.__unit = 'sats'; });
   await page.evaluate(() => { test.ui.pos = null; test.ui.posAtBoot = true; test.init(); }); await pause(50);
   check('the /pos link opens the till once a wallet is up', !!(await page.$('.pos-amount')));
   check('no browser errors', errors.length === 0);