Enable the prefer-destructuring eslint rule (#1858)

## Description:

Enable the `prefer-destructuring` eslint rule.

## Please complete the following:

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

eslint.config.js

@@ -118,6 +118,10 @@ export default [
       "object-shorthand": ["error", "always"],
       "no-undef": "error",
       "no-unused-vars": "off", // @typescript-eslint/no-unused-vars
+      "prefer-destructuring": ["error", {
+        array: false,
+        object: true,
+      }],
       "quote-props": ["error", "consistent-as-needed"],
       "sort-imports": "error",
       "space-before-blocks": ["error", "always"],

src/client/ClientGameRunner.ts

@@ -288,7 +288,7 @@ export class ClientGameRunner {
         this.saveGame(gu.updates[GameUpdateType.Win][0]);
       }
     });
-    const worker = this.worker;
+    const { worker } = this;
     const keepWorkerAlive = () => {
       if (this.isActive) {
         worker.sendHeartbeat();

src/client/Main.ts

@@ -613,7 +613,7 @@ function hasAllowedFlare(
   const allowed = config.allowedFlares();
   if (allowed === undefined) return true;
   if (userMeResponse === false) return false;
-  const flares = userMeResponse.player.flares;
+  const { flares } = userMeResponse.player;
   if (flares === undefined) return false;
   return allowed.length === 0 || allowed.some((f) => flares.includes(f));
 }

src/client/TerritoryPatternsModal.ts

@@ -389,7 +389,7 @@ export function generatePreviewDataUrl(
 
   // Create an image
   const imageData = ctx.createImageData(width, height);
-  const data = imageData.data;
+  const { data } = imageData;
   let i = 0;
   for (let y = 0; y < height; y++) {
     for (let x = 0; x < width; x++) {

src/client/Utils.ts

@@ -115,7 +115,7 @@ export const translateText = (
   let message = langSelector.translations[key];
 
   if (!message && langSelector.defaultTranslations) {
-    const defaultTranslations = langSelector.defaultTranslations;
+    const { defaultTranslations } = langSelector;
     if (defaultTranslations && defaultTranslations[key]) {
       message = defaultTranslations[key];
     }

src/client/components/baseComponents/setting/SettingKeybind.ts

@@ -74,7 +74,7 @@ export class SettingKeybind extends LitElement {
     if (!this.listening) return;
     e.preventDefault();
 
-    const code = e.code;
+    const { code } = e;
 
     this.value = code;
 

src/client/graphics/NameBoxCalculator.ts

@@ -85,8 +85,8 @@ export function createGrid(
     .fill(null as unknown as boolean[])
     .map(() => Array<boolean>(height).fill(false));
 
-  for (let x = scaledBoundingBox.min.x; x <= scaledBoundingBox.max.x; x++) {
-    for (let y = scaledBoundingBox.min.y; y <= scaledBoundingBox.max.y; y++) {
+  for (let { x } = scaledBoundingBox.min; x <= scaledBoundingBox.max.x; x++) {
+    for (let { y } = scaledBoundingBox.min; y <= scaledBoundingBox.max.y; y++) {
       const cell = new Cell(x * scalingFactor, y * scalingFactor);
       if (game.isOnMap(cell)) {
         const tile = game.ref(cell.x, cell.y);

src/client/graphics/SpriteLoader.ts

@@ -124,7 +124,7 @@ export const colorizeCanvas = (
   ctx.drawImage(source, 0, 0);
 
   const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
-  const data = imageData.data;
+  const { data } = imageData;
 
   const colorARgb = colorA.toRgb();
   const colorBRgb = colorB.toRgb();

src/client/graphics/fx/ConquestFx.ts

@@ -18,8 +18,8 @@ export function conquestFxFactory(
 ): Fx[] {
   const conquestFx: Fx[] = [];
   const conquered = game.player(conquest.conqueredId);
-  const x = conquered.nameLocation().x;
-  const y = conquered.nameLocation().y;
+  const { x } = conquered.nameLocation();
+  const { y } = conquered.nameLocation();
 
   const swordAnimation = new SpriteFx(
     animatedSpriteLoader,

src/client/graphics/layers/FxLayer.ts

@@ -71,11 +71,11 @@ export class FxLayer implements Layer {
       // Only display text fx for the current player
       return;
     }
-    const tile = bonus.tile;
+    const { tile } = bonus;
     const x = this.game.x(tile);
     let y = this.game.y(tile);
-    const gold = bonus.gold;
-    const troops = bonus.troops;
+    const { gold } = bonus;
+    const { troops } = bonus;
 
     if (gold > 0) {
       const shortened = renderNumber(gold, 0);
@@ -149,7 +149,7 @@ export class FxLayer implements Layer {
   }
 
   onRailroadEvent(railroad: RailroadUpdate) {
-    const railTiles = railroad.railTiles;
+    const { railTiles } = railroad;
     for (const rail of railTiles) {
       // No need for pseudorandom, this is fx
       const chanceFx = Math.floor(Math.random() * 3);

src/client/graphics/layers/NameLayer.ts

@@ -233,7 +233,7 @@ export class NameLayer implements Layer {
     };
 
     if (player.cosmetics.flag) {
-      const flag = player.cosmetics.flag;
+      const { flag } = player.cosmetics;
       if (flag !== undefined && flag !== null && flag.startsWith("!")) {
         const flagWrapper = document.createElement("div");
         applyFlagStyles(flagWrapper);

src/client/graphics/layers/StructureIconsLayer.ts

@@ -532,7 +532,7 @@ export class StructureIconsLayer implements Layer {
     const screenPos = this.transformHandler.worldToScreenCoordinates(worldPos);
 
     const { type, stage } = options;
-    const scale = this.transformHandler.scale;
+    const { scale } = this.transformHandler;
     const spritesEnabled = this.game
       .config()
       .userSettings()
@@ -612,7 +612,7 @@ export class StructureIconsLayer implements Layer {
     const screenPos = this.transformHandler.worldToScreenCoordinates(worldPos);
     screenPos.x = Math.round(screenPos.x);
 
-    const scale = this.transformHandler.scale;
+    const { scale } = this.transformHandler;
     screenPos.y = Math.round(
       scale >= ZOOM_THRESHOLD &&
         this.game.config().userSettings()?.structureSprites()

src/client/graphics/layers/TerritoryLayer.ts

@@ -393,7 +393,7 @@ export class TerritoryLayer implements Layer {
         break;
       }
 
-      const tile = entry.tile;
+      const { tile } = entry;
       this.paintTerritory(tile);
       for (const neighbor of this.game.neighbors(tile)) {
         this.paintTerritory(neighbor, true);
@@ -455,7 +455,7 @@ export class TerritoryLayer implements Layer {
       }
     } else {
       // Interior tiles
-      const pattern = owner.cosmetics.pattern;
+      const { pattern } = owner.cosmetics;
       const patternsEnabled = this.cachedTerritoryPatternsEnabled ?? false;
 
       // Alternative view only shows borders.

src/client/graphics/layers/UILayer.ts

@@ -263,7 +263,7 @@ export class UILayer implements Layer {
    * Draw health bar for a unit
    */
   public drawHealthBar(unit: UnitView) {
-    const maxHealth = this.game.unitInfo(unit.type()).maxHealth;
+    const { maxHealth } = this.game.unitInfo(unit.type());
     if (maxHealth === undefined || this.context === null) {
       return;
     }

src/client/utilities/RenderUnitTypeOptions.ts

@@ -36,7 +36,7 @@ export function renderUnitTypeOptions({
           type="checkbox"
           .checked=${disabledUnits.includes(type)}
           @change=${(e: Event) => {
-            const checked = (e.target as HTMLInputElement).checked;
+            const { checked } = (e.target as HTMLInputElement);
             toggleUnit(type, checked);
           }}
         />

src/core/PseudoRandom.ts

@@ -41,7 +41,7 @@ export class PseudoRandom {
 
   // Selects a random element from a set.
   randFromSet<T>(set: Set<T>): T {
-    const size = set.size;
+    const { size } = set;
     if (size === 0) {
       throw new Error("set must not be empty");
     }

src/core/execution/ConstructionExecution.ts

@@ -99,7 +99,7 @@ export class ConstructionExecution implements Execution {
   }
 
   private completeConstruction() {
-    const player = this.player;
+    const { player } = this;
     switch (this.constructionType) {
       case UnitType.AtomBomb:
       case UnitType.HydrogenBomb:

src/core/execution/FakeHumanExecution.ts

@@ -67,7 +67,7 @@ export class FakeHumanExecution implements Execution {
   }
 
   private updateRelationsFromEmbargos() {
-    const player = this.player;
+    const { player } = this;
     if (player === null) return;
     const others = this.mg.players().filter((p) => p.id() !== player.id());
 
@@ -90,7 +90,7 @@ export class FakeHumanExecution implements Execution {
   }
 
   private handleEmbargoesToHostileNations() {
-    const player = this.player;
+    const { player } = this;
     if (player === null) return;
     const others = this.mg.players().filter((p) => p.id() !== player.id());
 
@@ -248,7 +248,7 @@ export class FakeHumanExecution implements Execution {
     if (other.isTraitor()) {
       return false;
     }
-    const difficulty = this.mg.config().gameConfig().difficulty;
+    const { difficulty } = this.mg.config().gameConfig();
     if (
       difficulty === Difficulty.Hard ||
       difficulty === Difficulty.Impossible
@@ -491,7 +491,7 @@ export class FakeHumanExecution implements Execution {
   private structureSpawnTileValue(type: UnitType): (tile: TileRef) => number {
     if (this.player === null) throw new Error("not initialized");
     const borderTiles = this.player.borderTiles();
-    const mg = this.mg;
+    const { mg } = this;
     const otherUnits = this.player.units(type);
     // Prefer spacing structures out of atom bomb range
     const borderSpacing = this.mg.config().nukeMagnitudes(UnitType.AtomBomb).outer;

src/core/execution/PortExecution.ts

@@ -27,7 +27,7 @@ export class PortExecution implements Execution {
       throw new Error("Not initialized");
     }
     if (this.port === null) {
-      const tile = this.tile;
+      const { tile } = this;
       const spawn = this.player.canBuild(UnitType.Port, tile);
       if (spawn === false) {
         console.warn(

src/core/execution/RailroadExecution.ts

@@ -21,7 +21,7 @@ export class RailroadExecution implements Execution {
   /* eslint-disable sort-keys */
   init(mg: Game, ticks: number): void {
     this.mg = mg;
-    const tiles = this.railRoad.tiles;
+    const { tiles } = this.railRoad;
     // Inverse direction computation for the first tile
     this.railTiles.push({
       tile: tiles[0],

src/core/game/PlayerImpl.ts

@@ -846,7 +846,7 @@ export class PlayerImpl implements Player {
     if (existing.length === 0) {
       return false;
     }
-    const unit = existing[0].unit;
+    const { unit } = existing[0];
     if (!this.canUpgradeUnit(unit.type())) {
       return false;
     }

src/core/game/UnitGrid.ts

@@ -94,7 +94,7 @@ export class UnitGrid {
   private getCellsInRange(tile: TileRef, range: number) {
     const x = this.gm.x(tile);
     const y = this.gm.y(tile);
-    const cellSize = this.cellSize;
+    const { cellSize } = this;
     const [gridX, gridY] = this.getGridCoords(x, y);
     const startGridX = Math.max(
       0,

src/core/pathfinding/SerialAStar.ts

@@ -75,7 +75,7 @@ export class SerialAStar<NodeType> implements AStar<NodeType> {
     if (this.completed) return PathFindResultType.Completed;
 
     this.maxTries -= 1;
-    let iterations = this.iterations;
+    let { iterations } = this;
 
     while (!this.fwdOpenSet.isEmpty() && !this.bwdOpenSet.isEmpty()) {
       iterations--;

src/core/utilities/Line.ts

@@ -27,8 +27,8 @@ export class BezenhamLine {
     if (this.p1.x === this.p2.x && this.p1.y === this.p2.y) {
       return true;
     }
-    const x = this.p1.x;
-    const y = this.p1.y;
+    const { x } = this.p1;
+    const { y } = this.p1;
     const err2 = 2 * this.error;
 
     if (err2 > -this.dy) {

src/server/Master.ts

@@ -90,7 +90,7 @@ export async function startMaster() {
   cluster.on("message", (worker, message) => {
     if (message.type === "WORKER_READY") {
       // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-      const workerId = message.workerId;
+      const { workerId } = message;
       readyWorkers.add(workerId);
       log.info(
         `Worker ${workerId} is ready. (${readyWorkers.size}/${config.numWorkers()} ready)`,

src/server/Worker.ts

@@ -89,7 +89,7 @@ export async function startWorker() {
   app.post(
     "/api/create_game/:id",
     gatekeeper.httpHandler(LimiterType.Post, async (req, res) => {
-      const id = req.params.id;
+      const { id } = req.params;
       const creatorClientID = (() => {
         if (typeof req.query.creatorClientID !== "string") return undefined;
 

src/server/worker/websocket/handler/message/PreJoinHandler.ts

@@ -169,8 +169,7 @@ async function handleJoinMessage(
           success: false,
         };
       }
-      roles = result.player.roles;
-      flares = result.player.flares;
+      ({ roles, flares } = result.player);
 
       if (allowedFlares !== undefined) {
         // Login is required

tests/InputHandler.test.ts

@@ -79,7 +79,7 @@ describe("InputHandler AutoUpgrade", () => {
         }),
       );
 
-      const calls = mockEmit.mock.calls;
+      const { calls } = mockEmit.mock;
       const lastCall = calls[calls.length - 1];
       expect(lastCall[0]).not.toBeInstanceOf(AutoUpgradeEvent);
     });

tests/Warship.test.ts

@@ -38,7 +38,7 @@ describe("Warship", () => {
   });
 
   test("Warship heals only if player has port", async () => {
-    const maxHealth = game.config().unitInfo(UnitType.Warship).maxHealth;
+    const { maxHealth } = game.config().unitInfo(UnitType.Warship);
     if (typeof maxHealth !== "number") {
       expect(typeof maxHealth).toBe("number");
       throw new Error("unreachable");