A game that takes a rake has chips leaving the table every hand, and the bank check had no idea. It added up the buy-ins, added up the chips on the felt, and told the dealer somebody had been paid for chips they were never given — a shortfall that grows all night and points at a miscount that never happened. Every home game that takes a drop for the beer fund hits this on hand one. So the tool takes it, rather than watching it go. Under Table Setup: a percentage, an optional cap, and "no flop, no drop" — the rule almost everyone plays, on by default, where a hand that ends before the flop pays nothing. Zero percent is a game that doesn't rake, which is most of them and the default, and nothing about that game changes. Where it shows up is the point. The pot wizard says "House takes $2 of $40 — 5%, capped at $5" above the payouts, before a chip moves, because the summary is the dealer's last chance to disagree with the arithmetic and money taken quietly is the one thing a tool like this must never do. The bank check gets a House take line and says "balanced ... once the $2 in the house's cut is counted". The hand log keeps the pot as the table saw it with the cut recorded beside it, and the export has a column for it, so the night's total is one sum in a spreadsheet. Two decisions worth stating. The rake rounds *down* to a chip the table actually has: a house that can't make 40c takes nothing and the players keep it, which is the only way to be wrong about this that nobody argues with. And on a split pot it comes off the top, then what is left is shared in proportion — with the rounding leftovers going back to the winners rather than to the house, which asked for a number and gets that number, not that number plus dust. Measured end to end through the UI: 5% capped at $5 on a $40 pot pays $38 and banks $2; four stacks plus the cut come to exactly the $800 bought in; the bank check reads balanced. With no-flop-no-drop on, a hand folded round pre-flop pays the full $15 and takes nothing; with it off the same hand pays $14 and takes $1. Co-Authored-By: Claude Opus 5 <[email protected]> Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb
Hold'em dealer tests
Unit tests for the money logic behind /Casino/TexasHoldem — the betting engine, the
side-pot calculator, the split calculator and the table state.
node --test tests/holdem/*.test.js
No install step, no package.json, no dependencies. The browser modules are plain
script-tag files that each end with a module.exports guard, so Node can require them
as-is; load.js puts them on globalThis under the same names they use to find each
other in the page, in the load order from TexasHoldem.cshtml.
What's covered
| File | Covers |
|---|---|
potCalculator.test.js |
Main and side pots, dead money, uncalled bets, odd-cent distribution |
betting.test.js |
Blinds, street completion, raises reopening the action, all-in run-outs |
state.test.js |
Button rotation, which seats post blinds, session standings |
splitCalculator.test.js |
Chopped pots, odd chips, unmakeable denominations |
invariants.test.js |
1000 randomised hands per property (see below) |
The layout audit
The unit tests above cover the money. uiAudit.js covers the thing you can only see
in a browser: whether a dealer can actually reach every control.
node tests/holdem/runUiAudit.js # needs Playwright and the site running
It checks WCAG AA contrast, touch target sizes, touch-action and tap highlights, that fields stay selectable and are large enough not to trigger iOS zoom, that nothing important is covered or off-screen with no way to scroll to it, that no grid column has collapsed to nothing, and that no text is painted outside its box. It runs over the table, all five overlays and Quick Split, at thirteen viewports from a 360px phone to a 1600px desktop and the same phones on their side — each viewport twice, once with a mouse and once with a thumb.
That last part, and two of those checks, are newer than this paragraph claiming them.
runAll() did not include the contrast check at all, and touch targets sat behind an
opt-in flag nothing passed, so "the audit is clean" meant nine checks rather than
eleven for a long run of rounds. Both were written and tested and simply never called.
The mouse/thumb pair matters for the same reason: the 44px rule stands itself down
where hover: hover says there is a pointer, and a headless desktop browser is a
pointer, so a single pass had never measured a touch target at any viewport. Between
them they found a 9px seat label at 3.39:1, a 37px-tall amount field and a 30px delete
button on Quick Split.
A check that decides it doesn't apply says so in the output rather than reporting no offenders, which reads identically to a pass. The same goes for the two exemptions that exist: a disabled control, which WCAG itself excuses, and a link inside a sentence, whose size is set by the line it sits in.
Deliberately not in CI: the unit suite is dependency-free and runs in a second, while
this one needs a browser and a running site. Run it after any change that adds or
resizes a control. With no Playwright to hand, paste uiAudit.js into devtools and
call LayoutAudit.runAll().
The contrast check is built so it cannot report a false positive: backgrounds
composite through alpha, and where a gradient is involved every colour stop is tried
and the most flattering one used. A finding means the text fails even under the
reading most generous to it. Two earlier attempts at this got it wrong in both
directions — one read only background-color and scored text on a gradient against
nothing, the other treated low-alpha stops as opaque — so uiAudit.js is checked
against known-answer cases before it is believed.
Touch targets are measured by probing outward with elementFromPoint rather than by
reading the element box, because the box lies in both directions: a small control can
be padded out with a transparent ::after and respond well beyond its painted size,
and a checkbox inside a label is hit by tapping the label. The 44px rule is only
enforced where hover: none says there's no mouse.
It exists because these checks were being re-typed into a console every time something changed, and each time they only covered whatever had just been touched. That is how the standings table shipped with a player-name column zero pixels wide and kept it for two rounds.
Why the randomised suite exists
Every correctness bug found in this tool so far has been shape-dependent: blinds posted to empty chairs, the button skipping past players, heads-up acting out of order, an overbet announced as a side pot. None of them show up on a full six-handed table with equal stacks, which is the table anyone writes a fixed example for.
invariants.test.js deals a thousand hands across random seat counts, random empty
chairs, random stack depths and random dealer input, and checks the things a dealer
would notice being wrong:
- chips are never created or destroyed during play
- the pot breakdown plus the uncalled returns always equal the money that went in
- paying the pot out settles it to the cent
- once uncalled chips are handed back, nobody is still betting above the whole table
- the button and both blinds always land on players who are actually in the hand
The generator is seeded, so a failure reproduces from the seed printed in the message rather than being a flake to re-run.