chore: migrate to ESLint flat config

<https://eslint.org/docs/latest/use/configure/migration-guide#cli-flag-changes>

<https://eslint.org/docs/latest/use/configure/configuration-files-new>

eslint.config.js

@@ -0,0 +1,115 @@
+import configJs from "@eslint/js";
+import pluginTypescript from "@typescript-eslint/eslint-plugin";
+import parserTypescript from "@typescript-eslint/parser";
+import configPrettier from "eslint-config-prettier";
+import pluginImport from "eslint-plugin-import";
+import pluginPromise from "eslint-plugin-promise";
+import pluginSvelte from "eslint-plugin-svelte";
+import globals from "globals";
+import parserSvelte from "svelte-eslint-parser";
+
+/** @type {FlatConfig} */
+const baseConfig = {
+  ignores: ["dist/**", "src-tauri/target/**"],
+  plugins: {
+    import: pluginImport,
+    promise: pluginPromise,
+  },
+  languageOptions: {
+    ecmaVersion: "latest",
+    sourceType: "module",
+    globals: {
+      ...globals.browser,
+      ...globals.node,
+    },
+  },
+  rules: {
+    ...configJs.configs.recommended.rules,
+    ...pluginPromise.configs.recommended.rules,
+    ...configPrettier.rules,
+    eqeqeq: "warn",
+    "guard-for-in": "warn",
+    "no-console": "warn",
+    "prefer-arrow-callback": "warn",
+
+    "import/order": [
+      "warn",
+      {
+        alphabetize: {
+          order: "asc",
+        },
+      },
+    ],
+    "import/no-duplicates": "warn",
+
+    "promise/always-return": [
+      "warn",
+      {
+        ignoreLastCallback: true,
+      },
+    ],
+  },
+};
+
+/** @type {FlatConfig[]} */
+const config = [
+  {
+    ...baseConfig,
+    files: ["**/*.js"],
+  },
+  {
+    ...baseConfig,
+    files: ["**/*.ts"],
+    plugins: {
+      ...baseConfig.plugins,
+      "@typescript-eslint": pluginTypescript,
+    },
+    languageOptions: {
+      ...baseConfig.languageOptions,
+      parser: parserTypescript,
+      parserOptions: {
+        project: "./tsconfig.json",
+      },
+    },
+    settings: {
+      ...pluginImport.configs.typescript.settings,
+      "import/resolver": {
+        typescript: true,
+        node: true,
+      },
+    },
+    rules: {
+      ...baseConfig.rules,
+      ...pluginTypescript.configs["eslint-recommended"].rules,
+      ...pluginTypescript.configs.recommended.rules,
+      ...pluginTypescript.configs["recommended-requiring-type-checking"].rules,
+      ...pluginImport.configs.typescript.rules,
+      ...configPrettier.rules,
+      "@typescript-eslint/consistent-type-imports": "warn",
+    },
+  },
+  {
+    ...baseConfig,
+    files: ["**/*.d.ts"],
+  },
+  {
+    ...baseConfig,
+    files: ["**/*.svelte"],
+    plugins: {
+      ...baseConfig.plugins,
+      svelte: pluginSvelte,
+    },
+    languageOptions: {
+      ...baseConfig.languageOptions,
+      parser: parserSvelte,
+    },
+    rules: {
+      ...baseConfig.rules,
+      ...pluginSvelte.configs.base.overrides[0].rules,
+      ...pluginSvelte.configs.recommended.rules,
+      ...pluginSvelte.configs.prettier.rules,
+      ...configPrettier.rules,
+    },
+  },
+];
+export default config;

package.json

@@ -41,8 +41,10 @@
     "uuid": "^9.0.0"
   },
   "devDependencies": {
+    "@eslint/js": "^8.56.0",
     "@sveltejs/vite-plugin-svelte": "^3.0",
     "@tauri-apps/cli": "^1.2.2",
+    "@types/eslint": "^8.56.2",
     "@types/uuid": "^9.0.1",
     "@typescript-eslint/eslint-plugin": "^6.0.0",
     "@typescript-eslint/parser": "^6.0.0",
@@ -54,10 +56,12 @@
     "eslint-plugin-import": "^2.27.4",
     "eslint-plugin-promise": "^6.1.1",
     "eslint-plugin-svelte": "^2.32.2",
+    "globals": "^13.24.0",
     "madr": "^3.0.0",
     "npm-audit-resolver": "^3.0.0-RC.0",
     "prettier": "^3.0.0",
     "prettier-plugin-svelte": "^3.0.0",
+    "svelte-eslint-parser": "^0.33.1",
     "typescript": "^5.0.2",
     "vite": "^5.0"
   }