chore: setup eslint and prettier

.editorconfig

@@ -0,0 +1,15 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+charset = utf-8
+
+[*.js]
+indent_style = space
+indent_size = 2
+
+[{package.json,*.yml,*.cjson}]
+indent_style = space
+indent_size = 2

.eslintignore

@@ -0,0 +1,2 @@
+dist
+node_modules

.eslintrc

@@ -1,3 +1,52 @@
 {
-  "extends": "@antfu"
+  "extends": [
+    "@nuxtjs/eslint-config-typescript",
+    // Enable typescript-specific recommended rules
+    "plugin:@typescript-eslint/recommended",
+    // Turns off all rules that are unnecessary or might conflict with Prettier (needs to be last)
+    "prettier"
+  ],
+  "plugins": ["unused-imports"],
+  "rules": {
+    // Workaround for bug https://github.com/nuxt/eslint-config/issues/147
+    "no-useless-constructor": "off",
+    "@typescript-eslint/no-useless-constructor": "error",
+    // Don"t report unused imports (this is handled by prettier)
+    "unused-imports/no-unused-imports": "off",
+    // Report unused variables (except the ones prefixed with an underscore)
+    "unused-imports/no-unused-vars": [
+      "warn",
+      {
+        "vars": "all",
+        "varsIgnorePattern": "^_",
+        "args": "after-used",
+        "argsIgnorePattern": "^_"
+      }
+    ],
+    // Ensure void operator is not used, except for variable assignment or function return (might be handy for promises)
+    "no-void": ["error", { "allowAsStatement": true }],
+    // Demote this to warning as long as we are still using cjs modules
+    "import/named": "warn",
+    // Import order is handled by prettier (which is incompatible with this rule: https://github.com/simonhaenisch/prettier-plugin-organize-imports/issues/65)
+    "import/order": "off"
+  },
+  "overrides": [
+    {
+      "files": ["*.ts", "*.vue"],
+      // Parser supporting vue files
+      "parser": "vue-eslint-parser",
+      "parserOptions": {
+        // Use ts parser for ts files and for the script tag in vue files
+        "parser": "@typescript-eslint/parser",
+        // Path to tsconfig to enable rules that require type information
+        "project": "./tsconfig.eslint.json",
+        // Correctly handle vue files
+        "extraFileExtensions": [".vue"]
+      },
+      "extends": [
+        // Enable recommended rules for typescript that use typing information (may be CPU intensive)
+        "plugin:@typescript-eslint/recommended-requiring-type-checking"
+      ]
+    }
+  ]
 }

.prettierrc

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+{
+  "semi": false,
+  "singleQuote": true,
+  "singleAttributePerLine": true
+}

tsconfig.eslint.json

@@ -0,0 +1,12 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    // ensure that nobody can accidentally use this config for a build
+    "noEmit": true
+  },
+  "include": [
+    // whatever paths you intend to lint
+    "src",
+    "test"
+  ]
+}