BSOL

Bridge Solver Online

This is a fork of the original Bridge Solver Online authored by John Goacher (https://mirgo2.co.uk/bridgesolver/)

JavaScript

The application remains a static browser application, but its code is organized as native ES modules:

• js/startup.mjs initializes the application.
• js/bootstrap.mjs builds the page and parses URL parameters.
• js/events.mjs wires the main user-interface events.
• js/import.mjs, js/pbn.mjs, and js/xml.mjs handle supported input formats.
• js/board-renderer.mjs, js/hand-renderer.mjs, and js/play.mjs render and play boards.
• js/scoring.mjs, js/scorecard.mjs, js/ranking.mjs, and js/traveller.mjs handle results.
• js/workers.mjs manages the main and background DDS workers.
• js/worker/ contains the worker wrapper, DDS JavaScript runtime, and dds.wasm.
• js/ui-popups.mjs contains shared popup, dialog, and spinner behavior.

The modules use explicit imports and exports. Temporary window bridges preserve compatibility for remaining global call sites and should be removed only when all callers of a bridged API use imports. js/shared/bridge-utils.js intentionally remains a classic script because the classic DDS worker loads it with importScripts().

Language

To allow text (help text and display text) to appear in other languages the following concept has been applied:

• A language switcher has been created (changeLanguage()). Whereever possible displayed text is piped through this function
• Added flags on the frontpage to allow the switch of language
• Currently English and German are implemented
• The default language is initialized in js/startup.mjs (e.g. language="de"). Language codes follow the 2-character code (e.g. en, de)

Styles

The main stylesheet is ddummy.css. It contains:

• the responsive layout for the import controls, board, results, dialogs, and tables;
• the shared Verdana-based application typography and softer Arial typography for the board/play view;
• the teal application palette, with calmer read-only legends and stronger action-button colors;
• keyboard focus indicators and reduced-motion support.

HTML

• The browser continues to load the generated static index.html.
• Maintain the source fragments in html/ (head.html, start.html, main-view.html, overlays.html, and footer.html), not the generated file.
• Run npm run build:html after changing a fragment. The versioned pre-commit hook rebuilds and stages index.html automatically.
• HTML is validated with npm run validate:html.

Functionality

Layout and buttons

The layout is fluid up to a 1000px content width. Import and navigation controls wrap inside their fieldsets when necessary. Wide board and Traveller content scrolls within its local container instead of causing page-level overflow. Dialogs and progress overlays are constrained to the viewport on narrow screens.

Interactive controls have accessible names, visible keyboard focus, live status updates, and reduced-motion behavior. The language switcher, file input, dialogs, board number, and current play position expose appropriate labels or ARIA semantics.

Loading of hands

Hands can be entered and analyzed in various ways:

• Choosing a local file by clicking the respective button on the frontpage
• Dropping a file onto the area on the frontpage covering the buttons
• Paste (CTRL-V on Windows/Linux, CMD-V on Mac) on the frontpage
• Using the respective button on the frontpage to retrieve data from the clipboard (requires user consent to read from the clipboard)
• Manual input of single hands by using the respective button on the frontpage
• Loading a remote file via an URL parameter (e.g. ?file=https://example.com/tournament.pbn). The remote server has to allow loading data via HTTP header Header set Access-Control-Allow-Origin * or more specific Header set Access-Control-Allow-Origin "https://thedomain.com".
• Loading additional traveller data (if available) is possible through the URL parameter xml. (e.g. ?file=https://example.com/tournament.pbn&xml=https://example.com/tournament.json). A live example can be found here: Live example.
• Board data can be provided completely with URL paramters
• For an overview of all available URL parameters see the file URL-Parameters.html

Supported file formats:

• .pbn
• .dlm
• .lin (BBO play and hand record files)

Handling of content in .pbn files

The [Result section of a .pbn file can optionally contain plain text enclosed in curly brackets. If present the text contained within is displayed at the bottom of the respective board in a highlighted box. The text may contain HTML markup for styling purposes.

• When present in a .pbn file Play, Auction, Playerlist, Contract and Score have been added to the display similar to the handling of respective content in .lin files.

URL parameters

Two additional URL parameters have been implemented. For a full list of parameters see list of URL parameters

• lang: sets the language for displayed text including help text. Language is a two-character code, e.g. lang=de.
• nav: turns on/off the navigation buttons, e.g. nav=0 hides the navigation buttons.

Double Dummy Solver

Boards are analyzed using the double dummy solver authored by Bo Haglund / Sören Hein and implemented as a WebAssembly module. The analysis runs completely in the browser (no server component necessary).

The provided version is based on the DDS3 project (https://github.com/dds-bridge/dds) currently using the released version 3.1.

The sources for the WebAssembly module can be downloaded from here: https://github.com/krtschil/bsol-wasm/releases.

DDS/WASM runtime failures and browser Worker errors are reported through the application UI. Main-worker failures and background-analysis failures are handled separately; failed background workers are stopped so that an analysis cannot remain silently stuck.

Development

Install the development dependencies and run the checks:

npm ci
npm test
npm run build:html
npm run validate:html

The regression suite is in test/regression.test.js and currently covers the migrated module behavior as well as important compatibility bridges. The browser-only XML parser smoke test is test/xml-smoke.html. CI also checks JavaScript syntax, generated HTML freshness, HTML validity, and the XML smoke test.

==TODO==

Board display:

• Upper right quadrant: for BBO tournaments the bidding shows < and > buttons that allow navigation to the bidding of the next pair. For passed out hands the buttons are not visible. Must be corrected.
• When a pbn file contains play data and a traveller is also supplied (via URL) the play functionality is turned off. The pbn file alone shows correct behaviour. Example: hands/10807.pbn & hands/10807.json Must be corrected.

Traveller display:

• Hover popup of opponent's pair number is always misplaced far above the table. Should be more flexible just above or to the right of the hovered pair number
• "Contract was 4C": the suit name should be replaced by the respective symbol

AI support

Claude/Sonnet 5 and GitHub/Copilot helped in analyzing and fixing code where necessary.