## Problem
The ghost/build-menu price of a structure can show the wrong (inflated)
cost. Concretely: a player who owns a **captured** city and then starts
building their **first** city sees the 3rd-city price (**500k**) for
that build instead of the 2nd-city price (**250k**).
## Root cause
Structure cost scales as `2^(units built) × base` (city: 125k / 250k /
500k …), counted via:
```ts
Math.min(player.unitsOwned(type), player.unitsConstructed(type))
```
The `Math.min` is deliberate — it caps the count at how many you've
actually **built**, so **captured** units (owned but not built) don't
inflate the price.
`unitsConstructed()` defeated that by double-counting in-progress
builds:
```ts
const built = this.numUnitsConstructed[type] ?? 0; // already includes the building unit
let constructing = 0;
for (const unit of this._units) {
if (unit.type() !== type) continue;
if (!unit.isUnderConstruction()) continue;
constructing++; // counts the SAME unit again
}
return constructing + built; // doubled
```
`recordUnitConstructed()` is called in `buildUnit()` the moment the unit
is created — while it is still under construction — so
`numUnitsConstructed` already accounts for in-progress builds. The extra
loop counted them a second time.
With one captured city + one city under construction: `unitsOwned = 2`,
double-counted `unitsConstructed = 2`, so `Math.min(2, 2) = 2` → 500k.
Without the double-count it's `Math.min(2, 1) = 1` → 250k. ✅
The redundant loop is a leftover from #2378, which removed the separate
`UnitType.Construction` unit. Back then in-progress builds were a
distinct unit type **not** recorded in `numUnitsConstructed`, so the
loop was needed; afterward it became a pure double-count. This is a
long-standing latent bug — present identically on `v31` — not a recent
regression.
## Fix
`unitsConstructed()` now just returns `numUnitsConstructed[type]`, which
already includes under-construction builds.
## Tests
`tests/economy/ConstructionCost.test.ts` covers both:
- pure case (first city under construction) → still 250k
- captured city + first city under construction → was 500k, now 250k
(fails without the fix with `expected 2 to be 1`)
All related suites (economy, PlayerImpl, nation structure behavior,
upgrades, MIRV pricing, stats) — 144 tests — pass.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
OpenFront.io is an online real-time strategy game focused on territorial control and alliance building. Players compete to expand their territory, build structures, and form strategic alliances in various maps based on real-world geography.
This is a fork/rewrite of WarFront.io. Credit to https://github.com/WarFrontIO.
License
OpenFront source code is licensed under the GNU Affero General Public License v3.0
Current copyright notices appear in:
- Footer: "© OpenFront and Contributors"
- Loading screen: "© OpenFront and Contributors"
Modified versions must preserve these notices in reasonably visible locations.
See the LICENSE for complete requirements.
For asset licensing, see LICENSE-ASSETS.
For license history, see LICENSING.md.
🌟 Features
- Real-time Strategy Gameplay: Expand your territory and engage in strategic battles
- Alliance System: Form alliances with other players for mutual defense
- Multiple Maps: Play across various geographical regions including Europe, Asia, Africa, and more
- Resource Management: Balance your expansion with defensive capabilities
- Cross-platform: Play in any modern web browser
📋 Prerequisites
- npm (v10.9.2 or higher)
- A modern web browser (Chrome, Firefox, Edge, etc.)
🚀 Installation
-
Clone the repository
git clone https://github.com/openfrontio/OpenFrontIO.git cd OpenFrontIO -
Install dependencies
npm run instDo NOT use
npm installnornpm ibut instead use ournpm run inst. It runs the safernpm ci --ignore-scriptsto install dependencies exactly according to the versions inpackage-lock.jsonand doesn't run scripts. This can prevent being hit by a supply chain attack.
🎮 Running the Game
Development Mode
Run both the client and server in development mode with live reloading:
npm run dev
This will:
- Start the webpack dev server for the client
- Launch the game server with development settings
- Open the game in your default browser (to disable this behavior, set
SKIP_BROWSER_OPEN=truein your environment)
Client Only
To run just the client with hot reloading:
npm run start:client
Server Only
To run just the server with development settings:
npm run start:server-dev
Connecting to staging or production backends
Sometimes it's useful to connect to production servers when replaying a game, testing user profiles, purchases, or login flow.
To replay a production game, make sure you're on the same commit that the game you want to replay was executed on, you can find the
gitCommitvalue viahttps://api.openfront.io/game/[gameId]. Unfinished games cannot be replayed on localhost.
To connect to staging api servers:
npm run dev:staging
To connect to production api servers:
npm run dev:prod
🛠️ Development Tools
-
Format code:
npm run format -
Lint code:
npm run lint -
Lint and fix code:
npm run lint:fix -
Testing
npm test
🏗️ Project Structure
/src/client- Frontend game client/src/core- Deterministic game simulation/src/server- Backend game server/resources- Static assets (images, maps, etc.)
🤝 Contributing
Contributions and translations are welcome! See CONTRIBUTING.md for the workflow, the approved-issue process, project governance, and translation info.