chore: upgrade ESLint to v10 and fix newly surfaced issues (#4057)

`eslint-plugin-import-x` was the last thing blocking the ESLint v10
upgrade - it just got v10 support. So here we go.

The upgrade itself is tiny. The rest of the diff is cleanup from issues
ESLint v10 now catches: a few `let` declarations with initial values
that were immediately overwritten anyway (`no-useless-assignment`), and
`Translator` listed in `/* global */` in `main.js` and `module.js`.

Working through those `no-useless-assignment` warnings also surfaced a
dead default in `openmeteo`: `maxEntries: 5` in the constructor, which
was never actually doing anything - `openmeteo` never reads
`this.config.maxEntries` anywhere. And `weather.js` already sets that
default for all providers, so it was just a redundant duplicate. Removed
that too.

No runtime behavior changes.

defaultmodules/weather/providers/openmeteo.js

@@ -98,7 +98,6 @@ class OpenMeteoProvider {
 			pastDays: 0,
 			type: "current",
 			maxNumberOfDays: 5,
-			maxEntries: 5,
 			updateInterval: 10 * 60 * 1000,
 			...config
 		};
@@ -241,16 +240,14 @@ class OpenMeteoProvider {
 	}
 
 	#getQueryParameters () {
-		const maxEntriesLimit = ["daily", "forecast"].includes(this.config.type) ? 7 : this.config.type === "hourly" ? 48 : 0;
-		let maxEntries = this.config.maxEntries;
 		let maxNumberOfDays = this.config.maxNumberOfDays;
 
 		if (this.config.maxNumberOfDays !== undefined && !isNaN(parseFloat(this.config.maxNumberOfDays))) {
+			const maxEntriesLimit = ["daily", "forecast"].includes(this.config.type) ? 7 : this.config.type === "hourly" ? 48 : 0;
 			const daysFactor = ["daily", "forecast"].includes(this.config.type) ? 1 : this.config.type === "hourly" ? 24 : 0;
-			maxEntries = Math.max(1, Math.min(Math.round(parseFloat(this.config.maxNumberOfDays)) * daysFactor, maxEntriesLimit));
+			const maxEntries = Math.max(1, Math.min(Math.round(parseFloat(this.config.maxNumberOfDays)) * daysFactor, maxEntriesLimit));
 			maxNumberOfDays = Math.ceil(maxEntries / Math.max(1, daysFactor));
 		}
-		maxEntries = Math.max(1, Math.min(maxEntries, maxEntriesLimit));
 
 		const params = {
 			latitude: this.config.lat,
@@ -429,7 +426,7 @@ class OpenMeteoProvider {
 
 		// Add hourly data if available
 		if (parsedData.hourly) {
-			let h = 0;
+			let h;
 			const currentTime = parsedData.current_weather.time;
 
 			// Handle both data shapes: object with arrays or array of objects (after transpose)
@@ -522,8 +519,8 @@ class OpenMeteoProvider {
 		const now = new Date();
 
 		parsedData.hourly.forEach((weather, i) => {
-			// Skip past entries, collect only future hours up to maxEntries
-			if (weather.time <= now || hours.length >= this.config.maxEntries) {
+			// Skip past entries
+			if (weather.time <= now) {
 				return;
 			}
 

defaultmodules/weather/providers/openweathermap.js

@@ -135,7 +135,7 @@ class OpenWeatherMapProvider {
 	}
 
 	#generateWeatherObjectsFromOnecall (data) {
-		let precip = false;
+		let precip;
 
 		// Get current weather
 		const current = {};

defaultmodules/weather/providers/pirateweather.js

@@ -85,7 +85,7 @@ class PirateweatherProvider {
 			return;
 		}
 
-		let weatherData = null;
+		let weatherData;
 
 		switch (this.config.type) {
 			case "current":

defaultmodules/weather/providers/ukmetofficedatahub.js

@@ -116,7 +116,7 @@ class UkMetOfficeDataHubProvider {
 			return;
 		}
 
-		let weatherData = null;
+		let weatherData;
 
 		switch (this.config.type) {
 			case "current":

defaultmodules/weather/weatherutils.js

@@ -31,7 +31,7 @@ const WeatherUtils = {
 		if (valueUnit === "%") return `${value.toFixed(0)} ${valueUnit}`;
 
 		let convertedValue = value;
-		let conversionUnit = valueUnit;
+		let conversionUnit;
 		if (outputUnit === "imperial") {
 			convertedValue = this.convertPrecipitationToInch(value, valueUnit);
 			conversionUnit = "in";

js/http_fetcher.js

@@ -191,7 +191,7 @@ class HTTPFetcher extends EventEmitter {
 	#getDelayForResponse (response) {
 		const { status } = response;
 		let delay = this.reloadInterval;
-		let message = "";
+		let message;
 		let errorType = "UNKNOWN_ERROR";
 
 		if (status === 401 || status === 403) {

js/main.js

@@ -1,4 +1,4 @@
-/* global Loader, defaults, Translator, addAnimateCSS, removeAnimateCSS, AnimateCSSIn, AnimateCSSOut, modulePositions, io */
+/* global Loader, defaults, addAnimateCSS, removeAnimateCSS, AnimateCSSIn, AnimateCSSOut, modulePositions, io */
 
 const MM = (function () {
 	let modules = [];

js/module.js

@@ -1,4 +1,4 @@
-/* global Class, cloneObject, Loader, MMSocket, nunjucks, Translator */
+/* global Class, cloneObject, Loader, MMSocket, nunjucks */
 
 /*
  * Module Blueprint.

package.json

@@ -93,7 +93,7 @@
 		"ajv": "^8.18.0",
 		"animate.css": "^4.1.1",
 		"croner": "^10.0.1",
-		"eslint": "^9.39.4",
+		"eslint": "^10.0.3",
 		"express": "^5.2.1",
 		"feedme": "^2.0.2",
 		"helmet": "^8.1.0",
@@ -112,14 +112,15 @@
 		"weathericons": "^2.1.0"
 	},
 	"devDependencies": {
+		"@eslint/js": "^10.0.1",
 		"@stylistic/eslint-plugin": "^5.10.0",
 		"@vitest/coverage-v8": "^4.0.18",
-		"@vitest/eslint-plugin": "^1.6.9",
+		"@vitest/eslint-plugin": "^1.6.10",
 		"@vitest/ui": "^4.0.18",
 		"cspell": "^9.7.0",
-		"eslint-plugin-import-x": "^4.16.1",
-		"eslint-plugin-jsdoc": "^62.7.1",
-		"eslint-plugin-package-json": "^0.89.4",
+		"eslint-plugin-import-x": "^4.16.2",
+		"eslint-plugin-jsdoc": "^62.8.0",
+		"eslint-plugin-package-json": "^0.90.1",
 		"eslint-plugin-playwright": "^2.9.0",
 		"express-basic-auth": "^1.2.1",
 		"husky": "^9.1.7",