fix(frontend): WebGL2コンテキストの初期化に失敗するとMisskeyが起動できなくなる問題を修正 (#13587)

* Fixed startup crash with seasonal effects

(cherry picked from commit eba0c2cc61)

* Update Changelog

* Update Changelog

---------

Co-authored-by: Leah <kevinlukej@gmail.com>

CHANGELOG.md

@@ -13,6 +13,8 @@
 - Fix: 一部のページ内リンクが正しく動作しない問題を修正
 - Fix: 周年の実績が閏年を考慮しない問題を修正
 - Fix: ローカルURLのプレビューポップアップが左上に表示される
+- Fix: WebGL2をサポートしないブラウザで「季節に応じた画面の演出」が有効になっているとき、Misskeyが起動できなくなる問題を修正  
+  (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/459)
 
 ### Server
 - Enhance: エンドポイント`antennas/update`の必須項目を`antennaId`のみに

packages/frontend/src/boot/main-boot.ts

@@ -75,27 +75,31 @@ export async function mainBoot() {
 			mainRouter.push('/search');
 		},
 	};
-
-	if (defaultStore.state.enableSeasonalScreenEffect) {
-		const month = new Date().getMonth() + 1;
-		if (defaultStore.state.hemisphere === 'S') {
-			// ▼南半球
-			if (month === 7 || month === 8) {
-				const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SnowfallEffect({}).render();
-			}
-		} else {
-			// ▼北半球
-			if (month === 12 || month === 1) {
-				const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SnowfallEffect({}).render();
-			} else if (month === 3 || month === 4) {
-				const SakuraEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SakuraEffect({
-					sakura: true,
-				}).render();
+	try {
+		if (defaultStore.state.enableSeasonalScreenEffect) {
+			const month = new Date().getMonth() + 1;
+			if (defaultStore.state.hemisphere === 'S') {
+				// ▼南半球
+				if (month === 7 || month === 8) {
+					const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SnowfallEffect({}).render();
+				}
+			} else {
+				// ▼北半球
+				if (month === 12 || month === 1) {
+					const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SnowfallEffect({}).render();
+				} else if (month === 3 || month === 4) {
+					const SakuraEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SakuraEffect({
+						sakura: true,
+					}).render();
+				}
 			}
 		}	
+	} catch (error) {
+		// console.error(error);
+		console.error('Failed to initialise the seasonal screen effect canvas context:', error);
 	}
 
 	if ($i) {

packages/frontend/src/scripts/snowfall-effect.ts

@@ -155,7 +155,9 @@ export class SnowfallEffect {
 		max: 0.125,
 		easing: 0.0005,
 	};
-
+	/**
+	 * @throws {Error} - Thrown when it fails to get WebGL context for the canvas 
+	 */
 	constructor(options: {
 		sakura?: boolean;
 	}) {