Refactor codebase to functional style

Convert function declarations to arrow functions across all source files
(shared, client, server). Class methods left unchanged.

- Replace imperative loops with map/filter/reduce/find
- Convert let to const using functional patterns
- Add parameter destructuring throughout
- Reorder functions where needed (const not hoisted)
- Add jsdom devDependency for DOM testing

Author: rgilks

package-lock.json

@@ -25,6 +25,7 @@
     "@vitest/coverage-v8": "^4.1.0",
     "esbuild": "^0.27.4",
     "husky": "^9.1.7",
+    "jsdom": "^29.0.0",
     "tsx": "^4.21.0",
     "typescript": "^5.7.0",
     "vitest": "^4.0.18",

package.json

@@ -6,28 +6,28 @@
 let ctx: AudioContext | null = null;
 let muted = false;
 
-export function isMuted(): boolean {
+export const isMuted = (): boolean => {
   return muted;
-}
+};
 
-export function setMuted(m: boolean) {
+export const setMuted = (m: boolean) => {
   muted = m;
   // Persist preference
   try {
     localStorage.setItem('delta-v-mute', m ? '1' : '0');
   } catch {}
-}
+};
 
-function getCtx(): AudioContext | null {
+const getCtx = (): AudioContext | null => {
   if (muted) return null;
   if (!ctx) {
     ctx = new AudioContext();
   }
   return ctx;
-}
+};
 
 /** Resume audio context after user gesture (required by browsers). */
-export function initAudio() {
+export const initAudio = () => {
   // Load saved mute preference
   try {
     const saved = localStorage.getItem('delta-v-mute');
@@ -43,10 +43,10 @@ export function initAudio() {
   };
   document.addEventListener('click', resume);
   document.addEventListener('touchstart', resume);
-}
+};
 
 /** Short blip for UI interactions (button clicks, selections). */
-export function playSelect() {
+export const playSelect = () => {
   const ac = getCtx();
   if (!ac) return;
   const osc = ac.createOscillator();
@@ -60,10 +60,10 @@ export function playSelect() {
   gain.gain.exponentialRampToValueAtTime(0.001, ac.currentTime + 0.1);
   osc.start(ac.currentTime);
   osc.stop(ac.currentTime + 0.1);
-}
+};
 
 /** Confirm/submit sound — ascending tone. */
-export function playConfirm() {
+export const playConfirm = () => {
   const ac = getCtx();
   if (!ac) return;
   const osc = ac.createOscillator();
@@ -77,10 +77,10 @@ export function playConfirm() {
   gain.gain.exponentialRampToValueAtTime(0.001, ac.currentTime + 0.2);
   osc.start(ac.currentTime);
   osc.stop(ac.currentTime + 0.2);
-}
+};
 
 /** Thruster sound for movement. */
-export function playThrust() {
+export const playThrust = () => {
   const ac = getCtx();
   if (!ac) return;
   const bufSize = ac.sampleRate * 0.3;
@@ -102,10 +102,10 @@ export function playThrust() {
   filter.connect(gain);
   gain.connect(ac.destination);
   src.start(ac.currentTime);
-}
+};
 
 /** Laser/beam sound for combat. */
-export function playCombat() {
+export const playCombat = () => {
   const ac = getCtx();
   if (!ac) return;
   const osc = ac.createOscillator();
@@ -119,10 +119,10 @@ export function playCombat() {
   gain.gain.exponentialRampToValueAtTime(0.001, ac.currentTime + 0.35);
   osc.start(ac.currentTime);
   osc.stop(ac.currentTime + 0.35);
-}
+};
 
 /** Explosion sound for ship destruction or detonation. */
-export function playExplosion() {
+export const playExplosion = () => {
   const ac = getCtx();
   if (!ac) return;
   const bufSize = ac.sampleRate * 0.5;
@@ -144,10 +144,10 @@ export function playExplosion() {
   filter.connect(gain);
   gain.connect(ac.destination);
   src.start(ac.currentTime);
-}
+};
 
 /** Alert tone for phase changes. */
-export function playPhaseChange() {
+export const playPhaseChange = () => {
   const ac = getCtx();
   if (!ac) return;
   const osc = ac.createOscillator();
@@ -171,10 +171,10 @@ export function playPhaseChange() {
   gain2.gain.exponentialRampToValueAtTime(0.001, ac.currentTime + 0.25);
   osc2.start(ac.currentTime + 0.12);
   osc2.stop(ac.currentTime + 0.25);
-}
+};
 
 /** Warning beep for low timer. */
-export function playWarning() {
+export const playWarning = () => {
   const ac = getCtx();
   if (!ac) return;
   // Two short beeps
@@ -191,10 +191,10 @@ export function playWarning() {
     osc.start(t);
     osc.stop(t + 0.1);
   }
-}
+};
 
 /** Victory fanfare. */
-export function playVictory() {
+export const playVictory = () => {
   const ac = getCtx();
   if (!ac) return;
   const notes = [523, 659, 784, 1047]; // C5, E5, G5, C6
@@ -211,10 +211,10 @@ export function playVictory() {
     osc.start(t);
     osc.stop(t + 0.3);
   });
-}
+};
 
 /** Defeat sound. */
-export function playDefeat() {
+export const playDefeat = () => {
   const ac = getCtx();
   if (!ac) return;
   const notes = [400, 350, 300, 200]; // Descending
@@ -231,4 +231,4 @@ export function playDefeat() {
     osc.start(t);
     osc.stop(t + 0.35);
   });
-}
+};

src/client/audio.ts

@@ -43,15 +43,15 @@ export type AIActionPlan =
       aiPlayer: number;
     };
 
-function buildAIOrdnanceLogEntries(state: GameState, launches: OrdnanceLaunch[]): string[] {
+const buildAIOrdnanceLogEntries = (state: GameState, launches: OrdnanceLaunch[]): string[] => {
   return launches.map((launch) => {
     const ship = state.ships.find((candidate) => candidate.id === launch.shipId);
     const name = ship ? (SHIP_STATS[ship.type]?.name ?? ship.type) : launch.shipId;
     return `AI: ${name} launched ${launch.ordnanceType}`;
   });
-}
+};
 
-export function deriveAIActionPlan(
+export const deriveAIActionPlan = (
   state: GameState | null,
   playerId: number,
   map: SolarSystemMap,
@@ -61,7 +61,7 @@ export function deriveAIActionPlan(
     ordnance: aiOrdnance,
     combat: aiCombat,
   },
-): AIActionPlan {
+): AIActionPlan => {
   if (!state || state.phase === 'gameOver') {
     return { kind: 'none' };
   }
@@ -115,4 +115,4 @@ export function deriveAIActionPlan(
     kind: 'transition',
     aiPlayer,
   };
-}
+};

src/client/game-client-ai-flow.ts

@@ -6,19 +6,19 @@ export interface BriefingLogEntry {
   cssClass: string;
 }
 
-function getBriefingCssClass(line: string): string {
+const getBriefingCssClass = (line: string): string => {
   if (line.startsWith('Objective: Escape') || line.startsWith('Objective: Get') || line.startsWith('Objective: Land')) {
     return 'log-landed';
   }
   if (line.startsWith('Objective: Inspect') || line.startsWith('Objective: Destroy')) {
     return 'log-damage';
   }
   return '';
-}
+};
 
-export function deriveScenarioBriefingEntries(state: GameState, playerId: number): BriefingLogEntry[] {
+export const deriveScenarioBriefingEntries = (state: GameState, playerId: number): BriefingLogEntry[] => {
   return getScenarioBriefingLines(state, playerId).map((line) => ({
     text: line,
     cssClass: getBriefingCssClass(line),
   }));
-}
+};

src/client/game-client-briefing.ts

@@ -10,12 +10,12 @@ export type BurnChangePlan =
       clearOverload: boolean;
     };
 
-export function deriveBurnChangePlan(
+export const deriveBurnChangePlan = (
   state: GameState | null,
   selectedShipId: string | null,
   direction: number,
   currentBurn: number | null,
-): BurnChangePlan {
+): BurnChangePlan => {
   if (!state) {
     return { kind: 'noop' };
   }
@@ -52,4 +52,4 @@ export function deriveBurnChangePlan(
     nextBurn: currentBurn === direction ? null : direction,
     clearOverload: currentBurn !== direction,
   };
-}
+};