update eslint config

eslint.config.js

@@ -0,0 +1,73 @@
+export default [
+    {
+        env: {
+            browser: true,
+            es6: true,
+        },
+        parser: "babel-eslint",
+        parserOptions: {
+            ecmaVersion: 2020,
+            sourceType: "module",
+        },
+        rules: {
+            "no-debugger": "warn",
+            "no-dupe-keys": "warn",
+            "no-dupe-args": "warn",
+            "no-duplicate-case": "warn",
+            "no-empty": "warn",
+            "no-extra-semi": "warn",
+            "no-func-assign": "warn",
+            "no-obj-calls": "warn",
+            "no-sparse-arrays": "warn",
+            "no-unreachable": "warn",
+            "valid-typeof": "warn",
+            "no-multi-spaces": "warn",
+            "no-with": "warn",
+            curly: "warn",
+            "no-unused-expressions": "warn",
+            "no-shadow-restricted-names": "warn",
+            "no-undefined": "off",
+            camelcase: "warn",
+
+            indent: [
+                "warn",
+                4,
+                {
+                    MemberExpression: "off",
+                    SwitchCase: 1,
+                },
+            ],
+
+            "array-bracket-spacing": ["warn", "never"],
+            "comma-spacing": "warn",
+            "comma-style": "warn",
+            "computed-property-spacing": "warn",
+            "func-call-spacing": "warn",
+            "key-spacing": "warn",
+            "keyword-spacing": "warn",
+            "new-cap": "warn",
+            "no-mixed-spaces-and-tabs": "warn",
+            "one-var": [
+                "warn",
+                {
+                    var: "never",
+                    let: "never",
+                    const: "never",
+                },
+            ],
+            semi: "warn",
+            "space-in-parens": ["warn", "never"],
+            "space-before-blocks": "warn",
+            "unicode-bom": "warn",
+            "new-parens": "warn",
+            "no-nested-ternary": "warn",
+            "space-infix-ops": "warn",
+            "space-unary-ops": ["warn", { words: true, nonwords: false }],
+
+            // ES2015
+            "constructor-super": "warn",
+            "no-this-before-super": "warn",
+            "no-var": "warn",
+        },
+    },
+];