Minesweeper for VSCode

A classic Minesweeper game that runs inside Visual Studio Code.

• GitHub: https://github.com/zhanwangfeng/MinesweeperForVSCode
• VSCode: https://marketplace.visualstudio.com/items?itemName=zhanwangfeng.minesweeper-for-vscode

Features

• Activity Bar entry — a mine icon opens the Minesweeper view container.
• Main "Open Game" button — opens (or focuses) the game in a webview.
• TreeView difficulty selector — choose Easy / Medium / Hard; the current selection is highlighted and a "Select" action is available per item.
• Webview game board — left-click to reveal, right-click to flag, flood-fill, timers, and win/lose detection.
• Chord / clear — left-click an already-revealed number to auto-clear its neighbors once enough flags are placed.
• Mine odds (probability) hints — an Odds toggle button in the toolbar; when enabled, hovering an unrevealed cell shows a floating 💣 33% tooltip with the exact chance that the cell is a mine.
• Language switching (en / cn) — a toolbar button toggles the UI language; also respects the minesweeper.language setting (auto / en / cn) which follows the VSCode locale.
• Online multiplayer (LAN) — host-authoritative, turn-based mine guessing over your local network. Unlimited players share one board, pick one unrevealed cell per round and mark it as Mine or Not a mine, and compete on a score leaderboard.

Usage

1. Press the mine icon in the Activity Bar (or run command Minesweeper: Open Game).
2. Pick a difficulty from the TreeView on the left.
3. Play in the webview. Use Restart to reset and Switch Language to toggle en/cn.
4. Click Odds (✕ / ✓) in the toolbar to turn mine-probability hints on or off, then hover any unrevealed cell to see its odds.

Online Multiplayer (LAN)

Two extra TreeView entries appear below the difficulty items:

• Create Room (Online) — starts a room on your machine and shows your local IP:PORT (default port 18766). Share it with the other players.
• Join Room (Online) — asks for the host's IP:PORT and joins that room.

How a match works

1. The host opens the room webview and shares the IP:PORT shown in the header; players join by entering it there.
2. Everyone (including the host) appears in the lobby with their nickname, address and connection status. There is no player limit. The list is ordered for you: you are always first; if you are not the host, the host is shown second; then the other real players; bots are shown last. Within each group the join order is kept.
3. The host picks the board size inside the webview — 小 / 中 / 大 (Small / Medium / Large), i.e. 9×9 / 16×16 / 20×20 — and clicks Start Game once at least one other player has joined.
4. The board opens with one random safe cell already revealed — if it has no adjacent mines the reveal cascades through its neighbours, exactly like the first click of the single-player game.
5. Each round every player picks one unrevealed cell and marks it as Mine or Not a mine. A round lasts 20 seconds. You only see the other players' picks after you have made your own pick — so nobody can free-ride on others' choices.
6. When everyone has picked — or the 20-second timer runs out — all picked cells are revealed together. If everyone has already picked but time remains, the picks are held for about 3 seconds so you can study the board before the answer is shown. A picked cell that turns out to be a safe cell with no adjacent mines cascades open over its neighbours, exactly like the single-player game, so the board keeps opening up as you play.
7. Scoring scales with the number of players. Every cell is worth max(5, ceil(playerCount / 2)) points (the pot), where playerCount is the active pool. That pot is split among the players who picked that cell: each correct guess earns +max(1, ceil(pot / correctCount)) (shared equally), and each wrong guess loses −max(1, ceil(pot / wrongCount / 3)) (a third of the pot, shared equally). Players who did not pick in time keep their score unchanged. The result toast at the bottom of the window reports only your own outcome for the round.
8. Revealed cells show their true identity (a mine, or the adjacent-mine count) and can no longer be picked. Each player's current pick is shown as an icon in the player list (💣 = mine, ✓ = not a mine), and every picked cell shows a live tally: a green number top-left = players who guessed not a mine, and a red number bottom-right = players who guessed mine.
9. The whole match lasts 3 / 6 / 9 minutes for 小 / 中 / 大 (it scales with the board size). It ends when the timer reaches 0:00 or when every cell has been revealed, then a leaderboard is shown ranked by score (gold / silver / bronze for the top three).
10. If a player disconnects mid-round, their pick for that round is dropped and the lobby is updated, but their score is kept and the match continues.
11. Players (including bots) who join after a match has started are tagged Waiting for next game in the player list — they cannot pick during the current match and only become active when the next match begins.

Pick popup: on your turn, clicking an unrevealed cell opens a small popup where you mark it as Mine or Not a mine. Clicking anywhere else — or clicking an already-revealed cell — closes the popup. Clicking an already-revealed cell never opens it.

Game Over leaderboard: when the match ends, the score leaderboard (gold / silver / bronze for the top three) appears inside its own panel. It is kept within the panel with proper margins, and its player list scrolls independently if the room is too large to fit all players at once.

Nicknames

Every player (the host included) can set a display name while in the lobby by clicking the ✎ button next to their name in the player list; clients also have a nickname box in the sidebar. For clients the change is sent to the host and broadcast to all, while the host updates its own name directly. Names are capped at 16 characters. Renaming is lobby-only: once a match starts the rename entry points disappear and any unfinished edit is discarded, so you cannot change your name mid-match. Your nickname is saved the moment you set it and is automatically pre-filled the next time you open a room (host or client), so you only have to type it once.

Test bots

The host can click Add Bot in the room sidebar at any time to drop a local bot into the room. A bot counts as a regular player (it appears in the lobby, the board and the leaderboard, and keeps its score across games), so a single person can start a match and exercise the whole flow — Start Game becomes available as soon as one bot has joined.

Bots are simple: each round a bot waits a short random moment, then picks a random unrevealed cell and a random guess (a coin flip between Mine and Not a mine). They never use the odds hints or any board knowledge, and they need no network connection — they live entirely in the host's webview.

Networking note: the host's machine must be reachable from the other players on the same network (firewall allowing the chosen TCP port).

Mine Odds

The odds are exact, not a heuristic:

• Every revealed number cell becomes a constraint over its unrevealed neighbors (flags count as known mines and are subtracted from the number).
• Frontier cells are grouped into connected components by shared constraints; every legal mine layout of each component is enumerated with backtracking, unit propagation, and branching on the smallest constraint.
• Cells that touch no number are symmetric, so they are folded in with binomial coefficients instead of being enumerated.
• All components are combined by polynomial convolution under the global remaining-mine count, giving each cell a probability in [0, 1].

Consequences worth knowing:

• 0% means the cell is provably safe, 100% means it is provably a mine — both are certainties derived from the current board.
• On an untouched board there is no information yet, so every cell reports 0% until the first reveal.
• A 1500 ms computation budget guards against pathological hard-mode positions; if it is exceeded, hints for that move are simply skipped.
• Odds are only computed while a game is in progress (not after a win/loss) and only when the toggle is on.

Commands

Build & Run (for development)

npm install
npm run compile        # compile to dist/
# Press F5 in VSCode to launch the Extension Development Host

Package a .vsix (for a local install or a manual upload) or publish to the Marketplace:

npm run package        # -> minesweeper-for-vscode-<version>.vsix
npm run publish        # publish the current version to the VS Marketplace

Both commands trigger the vscode:prepublish script, which runs tsc — so there is no need to compile beforehand.

Configuration