Follow up per locale bundle (#16381)

* fix docker build

* enable check spdx license id in frontend-builder

* fix eslint config

* run eslint for frontend-builder in ci

* fix eslint

* add license headers

* fix unnecessary comments

* update changelog

* fix generateDts

* fix tsx

11 files changed, 110 insertions, 128 deletions

diff --git a/packages/frontend-builder/README.txt b/packages/frontend-builder/README.txt
index db878ffa83..428166e792 100644
--- a/packages/frontend-builder/README.txt
+++ b/packages/frontend-builder/README.txt
@@ -1,3 +1 @@
 This package contains the common scripts that are used to build the frontend and frontend-embed packages.
-
-
diff --git a/packages/frontend-builder/eslint.config.js b/packages/frontend-builder/eslint.config.js
index 5805c9924d..a13490c97f 100644
--- a/packages/frontend-builder/eslint.config.js
+++ b/packages/frontend-builder/eslint.config.js
@@ -1,20 +1,13 @@
 import globals from 'globals';
 import tsParser from '@typescript-eslint/parser';
-import pluginMisskey from '@misskey-dev/eslint-plugin';
 import sharedConfig from '../shared/eslint.config.js';
 
 // eslint-disable-next-line import/no-default-export
 export default [
 	...sharedConfig,
 	{
-		files: ['**/*.vue'],
-		...pluginMisskey.configs.typescript,
-	},
-	{
 		files: [
-			'@types/**/*.ts',
-			'js/**/*.ts',
-			'**/*.vue',
+			'**/*.ts',
 		],
 		languageOptions: {
 			globals: {
@@ -50,45 +43,6 @@ export default [
 			// e の禁止理由: error や event など、複数のキーワードの頭文字であり分かりにくいため
 			'id-denylist': ['error', 'window', 'e'],
 			'no-shadow': ['warn'],
-			'vue/attributes-order': ['error', {
-				alphabetical: false,
-			}],
-			'vue/no-use-v-if-with-v-for': ['error', {
-				allowUsingIterationVar: false,
-			}],
-			'vue/no-ref-as-operand': 'error',
-			'vue/no-multi-spaces': ['error', {
-				ignoreProperties: false,
-			}],
-			'vue/no-v-html': 'warn',
-			'vue/order-in-components': 'error',
-			'vue/html-indent': ['warn', 'tab', {
-				attribute: 1,
-				baseIndent: 0,
-				closeBracket: 0,
-				alignAttributesVertically: true,
-				ignores: [],
-			}],
-			'vue/html-closing-bracket-spacing': ['warn', {
-				startTag: 'never',
-				endTag: 'never',
-				selfClosingTag: 'never',
-			}],
-			'vue/multi-word-component-names': 'warn',
-			'vue/require-v-for-key': 'warn',
-			'vue/no-unused-components': 'warn',
-			'vue/no-unused-vars': 'warn',
-			'vue/no-dupe-keys': 'warn',
-			'vue/valid-v-for': 'warn',
-			'vue/return-in-computed-property': 'warn',
-			'vue/no-setup-props-reactivity-loss': 'warn',
-			'vue/max-attributes-per-line': 'off',
-			'vue/html-self-closing': 'off',
-			'vue/singleline-html-element-content-newline': 'off',
-			'vue/v-on-event-hyphenation': ['error', 'never', {
-				autofix: true,
-			}],
-			'vue/attribute-hyphenation': ['error', 'never'],
 		},
 	},
 	{
diff --git a/packages/frontend-builder/locale-inliner.ts b/packages/frontend-builder/locale-inliner.ts
index ce3f59a81c..75bcdc5b3f 100644
--- a/packages/frontend-builder/locale-inliner.ts
+++ b/packages/frontend-builder/locale-inliner.ts
@@ -1,11 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 import * as fs from 'fs/promises';
 import * as path from 'node:path';
-import { type Locale } from '../../locales/index.js';
-import type { Manifest as ViteManifest } from 'vite';
 import MagicString from 'magic-string';
 import { collectModifications } from './locale-inliner/collect-modifications.js';
 import { applyWithLocale } from './locale-inliner/apply-with-locale.js';
-import { blankLogger, type Logger } from './logger.js';
+import { blankLogger } from './logger.js';
+import type { Logger } from './logger.js';
+import type { Locale } from '../../locales/index.js';
+import type { Manifest as ViteManifest } from 'vite';
 
 export class LocaleInliner {
 	outputDir: string;
@@ -70,7 +76,7 @@ export class LocaleInliner {
 	async saveLocale(localeName: string, localeJson: Locale) {
 		// create directory
 		await fs.mkdir(path.join(this.outputDir, localeName), { recursive: true });
-		const localeLogger = localeName == 'ja-JP' ? this.logger : blankLogger; // we want to log for single locale only
+		const localeLogger = localeName === 'ja-JP' ? this.logger : blankLogger; // we want to log for single locale only
 		for (const chunk of this.chunks) {
 			if (!chunk.sourceCode || !chunk.modifications) {
 				throw new Error(`Source code or modifications for ${chunk.fileName} is not available.`);
diff --git a/packages/frontend-builder/locale-inliner/apply-with-locale.ts b/packages/frontend-builder/locale-inliner/apply-with-locale.ts
index a79ebb4253..5e601cdf12 100644
--- a/packages/frontend-builder/locale-inliner/apply-with-locale.ts
+++ b/packages/frontend-builder/locale-inliner/apply-with-locale.ts
@@ -1,6 +1,11 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 import MagicString from 'magic-string';
-import type { Locale } from '../../../locales/index.js';
 import { assertNever } from '../utils.js';
+import type { Locale, ILocale } from '../../../locales/index.js';
 import type { TextModification } from '../locale-inliner.js';
 import type { Logger } from '../logger.js';
 
@@ -13,16 +18,16 @@ export function applyWithLocale(
 ) {
 	for (const modification of modifications) {
 		switch (modification.type) {
-			case "delete":
+			case 'delete':
 				sourceCode.remove(modification.begin, modification.end);
 				break;
-			case "insert":
+			case 'insert':
 				sourceCode.appendRight(modification.begin, modification.text);
 				break;
-			case "replace":
+			case 'replace':
 				sourceCode.update(modification.begin, modification.end, modification.text);
 				break;
-			case "localized": {
+			case 'localized': {
 				const accessed = getPropertyByPath(localeJson, modification.localizationKey);
 				if (accessed == null) {
 					fileLogger.warn(`Cannot find localization key ${modification.localizationKey.join('.')}`);
@@ -30,7 +35,7 @@ export function applyWithLocale(
 				sourceCode.update(modification.begin, modification.end, JSON.stringify(accessed));
 				break;
 			}
-			case "parameterized-function": {
+			case 'parameterized-function': {
 				const accessed = getPropertyByPath(localeJson, modification.localizationKey);
 				let replacement: string;
 				if (typeof accessed === 'string') {
@@ -44,33 +49,33 @@ export function applyWithLocale(
 				sourceCode.update(modification.begin, modification.end, replacement);
 				break;
 
-				function formatFunction(accessed: string): string {
+				function formatFunction(format: string): string {
 					const params = new Set<string>();
 					const components: string[] = [];
 					let lastIndex = 0;
-					for (const match of accessed.matchAll(/\{(.+?)}/g)) {
+					for (const match of format.matchAll(/\{(.+?)}/g)) {
 						const [fullMatch, paramName] = match;
 						if (lastIndex < match.index) {
-							components.push(JSON.stringify(accessed.slice(lastIndex, match.index)));
+							components.push(JSON.stringify(format.slice(lastIndex, match.index)));
 						}
 						params.add(paramName);
 						components.push(paramName);
 						lastIndex = match.index + fullMatch.length;
 					}
-					components.push(JSON.stringify(accessed.slice(lastIndex)));
+					components.push(JSON.stringify(format.slice(lastIndex)));
 
 					// we replace with `(({name,count})=>(name+count+"some"))`
 					const paramList = Array.from(params).join(',');
-					let body = components.filter(x => x != '""').join('+');
-					if (body == '') body = '""'; // if the body is empty, we return empty string
+					let body = components.filter(x => x !== '""').join('+');
+					if (body === '') body = '""'; // if the body is empty, we return empty string
 					return `(({${paramList}})=>(${body}))`;
 				}
 			}
-			case "locale-name": {
+			case 'locale-name': {
 				sourceCode.update(modification.begin, modification.end, modification.literal ? JSON.stringify(localeName) : localeName);
 				break;
 			}
-			case "locale-json": {
+			case 'locale-json': {
 				// locale-json is inlined to place where initialize module-level variable which is executed only once.
 				// In such case we can use JSON.parse to speed up the parsing script.
 				// https://v8.dev/blog/cost-of-javascript-2019#json
@@ -84,14 +89,14 @@ export function applyWithLocale(
 	}
 }
 
-function getPropertyByPath(localeJson: any, localizationKey: string[]): string | object | null {
+function getPropertyByPath(localeJson: ILocale, localizationKey: string[]): string | object | null {
 	if (localizationKey.length === 0) return localeJson;
-	let current: any = localeJson;
+	let current: ILocale | string = localeJson;
 	for (const key of localizationKey) {
-		if (typeof current !== 'object' || current === null || !(key in current)) {
+		if (typeof current !== 'object' || !(key in current)) {
 			return null; // Key not found
 		}
 		current = current[key];
 	}
-	return current ?? null;
+	return current;
 }
diff --git a/packages/frontend-builder/locale-inliner/collect-modifications.ts b/packages/frontend-builder/locale-inliner/collect-modifications.ts
index 0cbf6a504e..59e5d96517 100644
--- a/packages/frontend-builder/locale-inliner/collect-modifications.ts
+++ b/packages/frontend-builder/locale-inliner/collect-modifications.ts
@@ -1,10 +1,15 @@
-import type { AstNode, ProgramNode } from 'rollup';
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 import { parseAst } from 'vite';
 import * as estreeWalker from 'estree-walker';
+import { assertNever, assertType } from '../utils.js';
+import type { AstNode, ProgramNode } from 'rollup';
 import type * as estree from 'estree';
 import type { LocaleInliner, TextModification } from '../locale-inliner.js';
-import type { Logger } from '../logger.js'
-import { assertNever, assertType } from '../utils.js';
+import type { Logger } from '../logger.js';
 
 // WalkerContext is not exported from estree-walker, so we define it here
 interface WalkerContext {
@@ -15,12 +20,12 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 	let programNode: ProgramNode;
 	try {
 		programNode = parseAst(sourceCode);
-	} catch (e) {
-		fileLogger.error(`Failed to parse source code: ${e}`);
+	} catch (err) {
+		fileLogger.error(`Failed to parse source code: ${err}`);
 		return [];
 	}
 	if (programNode.sourceType !== 'module') {
-		fileLogger.error(`Source code is not a module.`);
+		fileLogger.error('Source code is not a module.');
 		return [];
 	}
 
@@ -32,7 +37,7 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 	// 3) replace all `await window.fetch(`/assets/locales/${d}.${x}.json`).then(u=>u.json())` with `localeJson` variable
 	estreeWalker.walk(programNode, {
 		enter(this: WalkerContext, node: Node) {
-			assertType<AstNode>(node)
+			assertType<AstNode>(node);
 
 			if (node.type === 'Literal' && typeof node.value === 'string' && node.raw) {
 				if (node.raw.substring(1).startsWith(inliner.scriptsDir)) {
@@ -46,7 +51,7 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 						localizedOnly: true,
 					});
 				}
-				if (node.raw.substring(1, node.raw.length - 1) == `${inliner.scriptsDir}/${inliner.i18nFileName}`) {
+				if (node.raw.substring(1, node.raw.length - 1) === `${inliner.scriptsDir}/${inliner.i18nFileName}`) {
 					// we find `scripts/i18n.ts` literal.
 					// This is tipically in depmap and replace with this file name to avoid unnecessary loading i18n script
 					fileLogger.debug(`${lineCol(sourceCode, node)}: found ${inliner.i18nFileName} path literal ${node.raw}`);
@@ -81,17 +86,17 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 					localizedOnly: true,
 				});
 			}
-		}
-	})
+		},
+	});
 
 	const importSpecifierResult = findImportSpecifier(programNode, inliner.i18nFileName, 'i18n');
 
 	switch (importSpecifierResult.type) {
 		case 'no-import':
-			fileLogger.debug(`No import of i18n found, skipping inlining.`);
+			fileLogger.debug('No import of i18n found, skipping inlining.');
 			return modifications;
 		case 'no-specifiers':
-			fileLogger.debug(`Importing i18n without specifiers, removing the import.`);
+			fileLogger.debug('Importing i18n without specifiers, removing the import.');
 			modifications.push({
 				type: 'delete',
 				begin: importSpecifierResult.importNode.start,
@@ -115,17 +120,18 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 	let isSupported = true;
 	estreeWalker.walk(programNode, {
 		enter(node) {
-			if (node.type == 'VariableDeclaration') {
+			if (node.type === 'VariableDeclaration') {
 				assertType<estree.VariableDeclaration>(node);
-				for (let id of node.declarations.flatMap(x => declsOfPattern(x.id))) {
-					if (id == localI18nIdentifier) {
+				for (const id of node.declarations.flatMap(x => declsOfPattern(x.id))) {
+					if (id === localI18nIdentifier) {
 						isSupported = false;
 					}
 				}
 			}
-		}
-	})
+		},
+	});
 
+	// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
 	if (!isSupported) {
 		fileLogger.error(`Duplicated identifier "${localI18nIdentifier}" in variable declaration. Skipping inlining.`);
 		return modifications;
@@ -141,8 +147,8 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 	toSkip.add(i18nImport);
 	estreeWalker.walk(programNode, {
 		enter(this: WalkerContext, node, parent, property) {
-			assertType<AstNode>(node)
-			assertType<AstNode>(parent)
+			assertType<AstNode>(node);
+			assertType<AstNode>(parent);
 			if (toSkip.has(node)) {
 				// This is the import specifier, skip processing it
 				this.skip();
@@ -150,23 +156,23 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 			}
 
 			// We don't care original name part of the import declaration
-			if (node.type == 'ImportDeclaration') this.skip();
+			if (node.type === 'ImportDeclaration') this.skip();
 
 			if (node.type === 'Identifier') {
-				assertType<estree.Identifier>(node)
-				assertType<estree.Property | estree.MemberExpression | estree.ExportSpecifier>(parent)
-				if (parent.type === 'Property' && !parent.computed && property == 'key') return; // we don't care 'id' part of { id: expr }
-				if (parent.type === 'MemberExpression' && !parent.computed && property == 'property') return; // we don't care 'id' part of { id: expr }
-				if (parent.type === 'ExportSpecifier' && property == 'exported') return; // we don't care 'id' part of { id: expr }
-				if (node.name == localI18nIdentifier) {
+				assertType<estree.Identifier>(node);
+				assertType<estree.Property | estree.MemberExpression | estree.ExportSpecifier>(parent);
+				if (parent.type === 'Property' && !parent.computed && property === 'key') return; // we don't care 'id' part of { id: expr }
+				if (parent.type === 'MemberExpression' && !parent.computed && property === 'property') return; // we don't care 'id' part of { id: expr }
+				if (parent.type === 'ExportSpecifier' && property === 'exported') return; // we don't care 'id' part of { id: expr }
+				if (node.name === localI18nIdentifier) {
 					fileLogger.error(`${lineCol(sourceCode, node)}: Using i18n identifier "${localI18nIdentifier}" directly. Skipping inlining.`);
 					preserveI18nImport = true;
 				}
 			} else if (node.type === 'MemberExpression') {
 				assertType<estree.MemberExpression>(node);
 				const i18nPath = parseI18nPropertyAccess(node);
-				if (i18nPath != null && i18nPath.length >= 2 && i18nPath[0] == 'ts') {
-					if (parent.type === 'CallExpression' && property == 'callee') return; // we don't want to process `i18n.ts.property.stringBuiltinMethod()`
+				if (i18nPath != null && i18nPath.length >= 2 && i18nPath[0] === 'ts') {
+					if (parent.type === 'CallExpression' && property === 'callee') return; // we don't want to process `i18n.ts.property.stringBuiltinMethod()`
 					if (i18nPath.at(-1)?.startsWith('_')) fileLogger.debug(`found i18n grouped property access ${i18nPath.join('.')}`);
 					else fileLogger.debug(`${lineCol(sourceCode, node)}: found i18n property access ${i18nPath.join('.')}`);
 					// it's i18n.ts.propertyAccess
@@ -179,7 +185,7 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 						localizedOnly: true,
 					});
 					this.skip();
-				} else if (i18nPath != null && i18nPath.length >= 2 && i18nPath[0] == 'tsx') {
+				} else if (i18nPath != null && i18nPath.length >= 2 && i18nPath[0] === 'tsx') {
 					// it's parameterized locale substitution (`i18n.tsx.property(parameters)`)
 					// we expect the parameter to be an object literal
 					fileLogger.debug(`${lineCol(sourceCode, node)}: found i18n function access (object) ${i18nPath.join('.')}`);
@@ -197,11 +203,12 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 				// If there is 'i18n' in the parameters, we care interior of the function
 				if (node.params.flatMap(param => declsOfPattern(param)).includes(localI18nIdentifier)) this.skip();
 			}
-		}
-	})
+		},
+	});
 
+	// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
 	if (!preserveI18nImport) {
-		fileLogger.debug(`removing i18n import statement`);
+		fileLogger.debug('removing i18n import statement');
 		modifications.push({
 			type: 'delete',
 			begin: i18nImport.start,
@@ -211,7 +218,7 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 	}
 
 	function parseI18nPropertyAccess(node: estree.Expression | estree.Super): string[] | null {
-		if (node.type === 'Identifier' && node.name == localI18nIdentifier) return []; // i18n itself
+		if (node.type === 'Identifier' && node.name === localI18nIdentifier) return []; // i18n itself
 		if (node.type !== 'MemberExpression') return null;
 		// super.*
 		if (node.object.type === 'Super') return null;
@@ -219,7 +226,6 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 		// i18n?.property is not supported
 		if (node.optional) return null;
 
-
 		let id: string | null = null;
 		if (node.computed) {
 			if (node.property.type === 'Literal' && typeof node.property.value === 'string') {
@@ -243,10 +249,10 @@ export function collectModifications(sourceCode: string, fileName: string, fileL
 
 function declsOfPattern(pattern: estree.Pattern | null): string[] {
 	if (pattern == null) return [];
-	switch (pattern?.type) {
-		case "Identifier":
+	switch (pattern.type) {
+		case 'Identifier':
 			return [pattern.name];
-		case "ObjectPattern":
+		case 'ObjectPattern':
 			return pattern.properties.flatMap(prop => {
 				switch (prop.type) {
 					case 'Property':
@@ -254,16 +260,16 @@ function declsOfPattern(pattern: estree.Pattern | null): string[] {
 					case 'RestElement':
 						return declsOfPattern(prop.argument);
 					default:
-						assertNever(prop)
+						assertNever(prop);
 				}
 			});
-		case "ArrayPattern":
+		case 'ArrayPattern':
 			return pattern.elements.flatMap(p => declsOfPattern(p));
-		case "RestElement":
+		case 'RestElement':
 			return declsOfPattern(pattern.argument);
-		case "AssignmentPattern":
+		case 'AssignmentPattern':
 			return declsOfPattern(pattern.left);
-		case "MemberExpression":
+		case 'MemberExpression':
 			// assignment pattern so no new variable is declared
 			return [];
 		default:
@@ -375,15 +381,15 @@ type SpecifierResult =
 
 function findImportSpecifier(programNode: ProgramNode, i18nFileName: string, i18nSymbol: string): SpecifierResult {
 	const imports = programNode.body.filter(x => x.type === 'ImportDeclaration');
-	const importNode = imports.find(x => x.source.value === `./${i18nFileName}`) as estree.ImportDeclaration;
+	const importNode = imports.find(x => x.source.value === `./${i18nFileName}`) as estree.ImportDeclaration | undefined;
 	if (!importNode) return { type: 'no-import' };
 	assertType<AstNode>(importNode);
 
-	if (importNode.specifiers.length == 0) {
+	if (importNode.specifiers.length === 0) {
 		return { type: 'no-specifiers', importNode };
 	}
 
-	if (importNode.specifiers.length != 1) {
+	if (importNode.specifiers.length !== 1) {
 		return { type: 'unexpected-specifiers', importNode };
 	}
 	const i18nImportSpecifier = importNode.specifiers[0];
diff --git a/packages/frontend-builder/logger.ts b/packages/frontend-builder/logger.ts
index a3f66730e2..c619882380 100644
--- a/packages/frontend-builder/logger.ts
+++ b/packages/frontend-builder/logger.ts
@@ -1,4 +1,11 @@
-const debug = false;
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import * as process from 'node:process';
+
+const debug = process.env.BUILDER_DEBUG !== undefined && process.env.BUILDER_DEBUG !== '0';
 
 export interface Logger {
 	debug(message: string): void;
@@ -27,7 +34,7 @@ export function createLogger(): RootLogger {
 type LogContext = {
 	warningCount: number;
 	errorCount: number;
-}
+};
 
 function loggerFactory(prefix: string, context: LogContext): RootLogger {
 	return {
@@ -63,4 +70,4 @@ export const blankLogger: Logger = {
 	error: () => void 0,
 	info: () => void 0,
 	prefixed: () => blankLogger,
-}
+};
diff --git a/packages/frontend-builder/rollup-plugin-remove-unref-i18n.ts b/packages/frontend-builder/rollup-plugin-remove-unref-i18n.ts
index 9010e6910c..4a2bfa67d9 100644
--- a/packages/frontend-builder/rollup-plugin-remove-unref-i18n.ts
+++ b/packages/frontend-builder/rollup-plugin-remove-unref-i18n.ts
@@ -4,18 +4,18 @@
  */
 
 import * as estreeWalker from 'estree-walker';
-import type { Plugin } from 'vite';
-import type { CallExpression, Expression, Program, } from 'estree';
 import MagicString from 'magic-string';
-import type { AstNode } from 'rollup';
 import { assertType } from './utils.js';
+import type { Plugin } from 'vite';
+import type { CallExpression, Expression, Program } from 'estree';
+import type { AstNode } from 'rollup';
 
 // This plugin transforms `unref(i18n)` to `i18n` in the code, which is useful for removing unnecessary unref calls
 // and helps locale inliner runs after vite build to inline the locale data into the final build.
 //
 // locale inliner cannot know minifiedSymbol(i18n) is 'unref(i18n)' or 'otherFunctionsWithEffect(i18n)' so
 // it is necessary to remove unref calls before minification.
-export default function pluginRemoveUnrefI18n(
+export function pluginRemoveUnrefI18n(
 	{
 		i18nSymbolName = 'i18n',
 	}: {
@@ -42,12 +42,12 @@ export default function pluginRemoveUnrefI18n(
 							magicString.remove(arg.end, node.end);
 						}
 					}
-				}
+				},
 			});
 			return {
 				code: magicString.toString(),
 				map: magicString.generateMap({ hires: true }),
-			}
+			};
 		},
 	};
 }
diff --git a/packages/frontend-builder/utils.ts b/packages/frontend-builder/utils.ts
index 1ce9f7fc76..71ffebe03e 100644
--- a/packages/frontend-builder/utils.ts
+++ b/packages/frontend-builder/utils.ts
@@ -1,5 +1,10 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
 
 export function assertNever(x: never): never {
+	// eslint-disable-next-line @typescript-eslint/no-explicit-any
 	throw new Error(`Unexpected type: ${(x as any)?.type ?? x}`);
 }
 
diff --git a/packages/frontend-embed/vite.config.ts b/packages/frontend-embed/vite.config.ts
index eb57db9774..3ddee9b8a9 100644
--- a/packages/frontend-embed/vite.config.ts
+++ b/packages/frontend-embed/vite.config.ts
@@ -8,7 +8,7 @@ import locales from '../../locales/index.js';
 import meta from '../../package.json';
 import packageInfo from './package.json' with { type: 'json' };
 import pluginJson5 from './vite.json5.js';
-import pluginRemoveUnrefI18n from '../frontend-builder/rollup-plugin-remove-unref-i18n';
+import { pluginRemoveUnrefI18n } from '../frontend-builder/rollup-plugin-remove-unref-i18n';
 
 const url = process.env.NODE_ENV === 'development' ? yaml.load(await fsp.readFile('../../.config/default.yml', 'utf-8')).url : null;
 const host = url ? (new URL(url)).hostname : undefined;
diff --git a/packages/frontend-shared/js/i18n.ts b/packages/frontend-shared/js/i18n.ts
index bd9ba0922a..3b103c4714 100644
--- a/packages/frontend-shared/js/i18n.ts
+++ b/packages/frontend-shared/js/i18n.ts
@@ -28,7 +28,8 @@ type ParametersOf<T extends ILocale, TKey extends FlattenKeys<T, ParameterizedSt
 		: never;
 
 type Tsx<T extends ILocale> = {
-	readonly [K in keyof T as T[K] extends string ? never : K]: T[K] extends ParameterizedString<infer P>
+	// `string extends T[K] ? never : K` part removes non-parameterized string keys from Tsx type.
+	readonly [K in keyof T as string extends T[K] ? never : K]: T[K] extends ParameterizedString<infer P>
 		? (arg: { readonly [_ in P]: string | number }) => string
 		// @ts-expect-error -- 証明省略
 		: Tsx<T[K]>;
diff --git a/packages/frontend/vite.config.ts b/packages/frontend/vite.config.ts
index e9707d13d1..9b54014b54 100644
--- a/packages/frontend/vite.config.ts
+++ b/packages/frontend/vite.config.ts
@@ -14,7 +14,7 @@ import pluginJson5 from './vite.json5.js';
 import pluginCreateSearchIndex from './lib/vite-plugin-create-search-index.js';
 import type { Options as SearchIndexOptions } from './lib/vite-plugin-create-search-index.js';
 import pluginWatchLocales from './lib/vite-plugin-watch-locales.js';
-import pluginRemoveUnrefI18n from '../frontend-builder/rollup-plugin-remove-unref-i18n.js';
+import { pluginRemoveUnrefI18n } from '../frontend-builder/rollup-plugin-remove-unref-i18n.js';
 
 const url = process.env.NODE_ENV === 'development' ? yaml.load(await fsp.readFile('../../.config/default.yml', 'utf-8')).url : null;
 const host = url ? (new URL(url)).hostname : undefined;