Feat: Sierpinski map - live play-tested

[bijx]

Description:

Map requested by creator on dev discord and playtested by 42 players on Rex's stream, adds map Sierpinski, which is a sierpinski carpet shape. The map is a "party map" great for private matches, but is not part of the public map rotation.

Screen.Recording.2026-01-08.010120.mp4

Please complete the following:

• I have added screenshots for all UI updates
• I process any text displayed to the user through translateText() and I've added it to the en.json file
• I have added relevant tests to the test directory
• I confirm I have thoroughly tested these changes and take full responsibility for any bugs introduced

Please put your Discord username so you can be contacted if a bug or regression is found:

bijx

[coderabbitai]

Walkthrough

This PR adds a new "Sierpinski" map to the game by registering it in the map generator, defining its structure and dimensions, localizing its name, configuring player counts, and assigning it to the arcade map category. The Didier map is concurrently reclassified from fantasy to arcade.

Changes

Cohort / File(s)	Summary
Map Assets and Descriptors map-generator/assets/maps/sierpinski/info.json, resources/maps/sierpinski/manifest.json	Added new Sierpinski map definition with 9 nations, coordinates, and regional dimensions for three zoom levels (map, map16x, map4x)
Map Registry and Localization map-generator/main.go, resources/lang/en.json	Registered sierpinski entry in map generator; added map name localization and new "arcade" category label in language file
Game Type System src/core/game/Game.ts	Extended GameMapType enum with Sierpinski; moved Didier from fantasy to arcade category; added Sierpinski to arcade category
Client and Configuration src/client/components/Maps.ts, src/core/configuration/DefaultConfig.ts	Added Sierpinski to MapDescription export; configured player count limits [20, 15, 10] for the new map

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• New Map! "Surrounded" 🏝️ #2770 — Adds new map with parallel changes to GameMapType enum, numPlayersConfig, MapDescription, and locale/manifest files
• Add Manicouagan Map and Credit OpenTopography #2620 — Adds new map with matching code-level modifications across map-generator, resources, and configuration files
• Feat: Lemnos Map #2683 — Adds new map with corresponding edits to same code constructs (enum, MapDescription, numPlayersConfig, registry)

Suggested labels

Feature - Map

Suggested reviewers

• evanpelle

Poem

🔺 A fractal map is born today,
Sierpinski shows the fractal way,
Nine nations dance in infinite grace,
Arcade's newest, nested space!
Didier joins the arcade fold,
Ancient patterns, new and bold. 🎮

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main change: adding the Sierpinski map that has been play-tested, which aligns with the changeset's primary purpose.
Description check	✅ Passed	The description provides comprehensive context about the map's origin, testing, purpose, and includes relevant screenshots and video links, all directly related to the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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[iiamlewis]

@bijx if this is added, can we keep it out of the main rotation of maps for now please

[bijx]

@bijx if this is added, can we keep it out of the main rotation of maps for now please

For sure. It's a fun party map but we don't even have to add it. I'm curious to see what others think since it's such a different map compared to the rest which are more realistic

[iiamlewis]

@bijx could we add a new section to the maps, a new category called "community" maps or "party" maps, which contains maps like this and the Didier map

[bijx]

@iiamlewis I called it "Arcade" because it matches what other RTS games do, how does that sound?

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

src/core/game/Game.ts (1)

127-178: Type the category keys as a union to prevent drift now that a 4th category exists.
Right now Record<string, GameMapType[]> won’t catch typos (e.g., "arcades") and won’t force callers to handle new categories.

Proposed diff

-export const mapCategories: Record<string, GameMapType[]> = {
+export type MapCategoryKey = "continental" | "regional" | "fantasy" | "arcade";
+
+export const mapCategories: Record<MapCategoryKey, GameMapType[]> = {
   continental: [
     GameMapType.World,
     GameMapType.GiantWorldMap,
     GameMapType.NorthAmerica,
     GameMapType.SouthAmerica,
     GameMapType.Europe,
     GameMapType.EuropeClassic,
     GameMapType.Asia,
     GameMapType.Africa,
     GameMapType.Oceania,
   ],
   regional: [
     GameMapType.BritanniaClassic,
     GameMapType.Britannia,
     GameMapType.BlackSea,
     GameMapType.GatewayToTheAtlantic,
     GameMapType.BetweenTwoSeas,
     GameMapType.Iceland,
     GameMapType.EastAsia,
     GameMapType.Mena,
     GameMapType.Australia,
     GameMapType.FaroeIslands,
     GameMapType.FalklandIslands,
     GameMapType.Baikal,
     GameMapType.Halkidiki,
     GameMapType.StraitOfGibraltar,
     GameMapType.Italia,
     GameMapType.Japan,
     GameMapType.Montreal,
     GameMapType.GulfOfStLawrence,
     GameMapType.Lisbon,
     GameMapType.NewYorkCity,
     GameMapType.Manicouagan,
     GameMapType.Lemnos,
     GameMapType.TwoLakes,
     GameMapType.StraitOfHormuz,
     GameMapType.AmazonRiver,
   ],
   fantasy: [
     GameMapType.Pangaea,
     GameMapType.Pluto,
     GameMapType.Mars,
     GameMapType.DeglaciatedAntarctica,
     GameMapType.Achiran,
     GameMapType.BaikalNukeWars,
     GameMapType.FourIslands,
     GameMapType.Svalmel,
     GameMapType.Surrounded,
   ],
   arcade: [GameMapType.Didier, GameMapType.Sierpinski],
 };

📜 Review details

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d4d4822 and ad6d78c.

📒 Files selected for processing (5)

• map-generator/main.go
• resources/lang/en.json
• src/client/components/Maps.ts
• src/core/configuration/DefaultConfig.ts
• src/core/game/Game.ts

🚧 Files skipped from review as they are similar to previous changes (2)

• src/core/configuration/DefaultConfig.ts
• map-generator/main.go

🧰 Additional context used

🧠 Learnings (3)

📓 Common learnings

Learnt from: TheGiraffe3
Repo: openfrontio/OpenFrontIO PR: 2306
File: src/core/game/Game.ts:141-141
Timestamp: 2025-10-27T08:59:47.620Z
Learning: In OpenFrontIO, gamemode-specific map variants that have altered geography from their real-world counterparts should be categorized as "fantasy" rather than "regional", even if based on real locations. Example: BaikalNukeWars is in "fantasy" because it has different islands than real Baikal.

📚 Learning: 2025-08-27T08:12:19.610Z

Learnt from: mokizzz
Repo: openfrontio/OpenFrontIO PR: 1940
File: resources/lang/en.json:763-766
Timestamp: 2025-08-27T08:12:19.610Z
Learning: In OpenFrontIO, some country entries in src/client/data/countries.json may have similar names but different codes (e.g., "Empire of Japan" vs "Empire of Japan1"). Each unique code requires its own translation key in resources/lang/en.json after normalization. Always verify against countries.json before suggesting removal of translation keys.

Applied to files:

• resources/lang/en.json

📚 Learning: 2025-10-27T08:59:47.620Z

Learnt from: TheGiraffe3
Repo: openfrontio/OpenFrontIO PR: 2306
File: src/core/game/Game.ts:141-141
Timestamp: 2025-10-27T08:59:47.620Z
Learning: In OpenFrontIO, gamemode-specific map variants that have altered geography from their real-world counterparts should be categorized as "fantasy" rather than "regional", even if based on real locations. Example: BaikalNukeWars is in "fantasy" because it has different islands than real Baikal.

Applied to files:

• resources/lang/en.json

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Deploy to openfront.dev

🔇 Additional comments (5)

resources/lang/en.json (2)

212-261: Add is consistent with map-key normalization (lowercase, no spaces).
sierpinski matches the existing pattern (newyorkcity, giantworldmap, etc.), so this should resolve correctly via the normal map-key translation lookup.

---

262-267: Don't update non-English locale files in this PR.

The map_categories.arcade and sierpinski keys in en.json are correct. Other locale files will be updated by the translation team in dedicated translation PRs. Regular PRs should only modify en.json; the project has a separate workflow for all other language files.

src/client/components/Maps.ts (1)

11-58: Good: MapDescription stays exhaustive after adding GameMapType.Sierpinski.
This keeps the compile-time “missing map label” guard working.

src/core/game/Game.ts (2)

72-118: Enum addition looks clean.
GameMapType.Sierpinski = "Sierpinski" matches the existing naming style and should be stable for serialization.

---

127-178: No action needed—the codebase already uses dynamic category iteration. Both SinglePlayerModal.ts and HostLobbyModal.ts iterate over mapCategories using Object.entries() rather than hard-coding category names, so the arcade category is automatically included in the UI without any changes to caller code.

Likely an incorrect or invalid review comment.