Migrate ESLint to v9 flat config

Signed-off-by: Siddhi sahu <himanisahu739@gmail.com>

Author: Siddhi-sahu

.eslintignore

@@ -0,0 +1,141 @@
+const {
+  defineConfig,
+} = require("eslint/config");
+
+const globals = require("globals");
+const babelParser = require("@babel/eslint-parser");
+const react = require("eslint-plugin-react");
+const js = require("@eslint/js");
+
+const {
+  FlatCompat,
+} = require("@eslint/eslintrc");
+
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all
+});
+
+module.exports = defineConfig([{
+  ignores: [
+    "node_modules/**",
+    "**/*.test.js",
+    "src/utils/**",
+    ".cache/**",
+    ".github/**",
+    "assets/**",
+    "public/**",
+    ".babelrc",
+    ".env.development",
+    "CNAME",
+    "CODE_OF_CONDUCT.md",
+    "CODEOWNERS",
+    "font-preload-cache.json",
+    "LICENSE",
+    "Makefile",
+    "README.md",
+    "package.json",
+    "package-lock.json",
+    "static/**",
+  ]
+},
+{
+  languageOptions: {
+    globals: {
+      ...globals.browser,
+      ...globals.node,
+      ...globals.amd,
+    },
+
+    parser: babelParser,
+    "ecmaVersion": 2018,
+    "sourceType": "module",
+
+    parserOptions: {
+      "ecmaFeatures": {
+        "jsx": true,
+      },
+    },
+  },
+
+  "settings": {
+    "react": {
+      "version": "detect",
+    },
+  },
+
+  extends: compat.extends("eslint:recommended", "plugin:react/recommended"),
+
+  plugins: {
+    react,
+  },
+
+  "rules": {
+    "array-bracket-spacing": ["error", "never"],
+    "comma-style": ["error"],
+
+    "arrow-spacing": ["error", {
+      "after": true,
+      "before": true,
+    }],
+
+    "block-scoped-var": "error",
+    "block-spacing": "error",
+    "brace-style": ["error", "1tbs"],
+    "jsx-quotes": ["error", "prefer-double"],
+    "keyword-spacing": "error",
+
+    "key-spacing": ["error", {
+      "beforeColon": false,
+      "afterColon": true,
+    }],
+
+    "no-unused-vars": ["warn", {
+      "varsIgnorePattern": "React",
+    }],
+
+    "no-trailing-spaces": "error",
+    "object-curly-spacing": ["error", "always"],
+    "react/display-name": 0,
+    "react/prop-types": 0,
+    "react/no-unescaped-entities": [0],
+    "react/jsx-no-duplicate-props": [0],
+
+    "indent": ["error", 2, {
+      "FunctionExpression": {
+        "parameters": "first",
+      },
+
+      "FunctionDeclaration": {
+        "parameters": "first",
+      },
+
+      "MemberExpression": 1,
+      "SwitchCase": 1,
+      "outerIIFEBody": 0,
+
+      "VariableDeclarator": {
+        "var": 2,
+        "let": 2,
+        "const": 3,
+      },
+
+      ignoredNodes: ["TemplateLiteral"],
+    }],
+
+    "linebreak-style": ["error", "unix"],
+    "quotes": ["error", "double"],
+    "semi": ["error", "always"],
+    "strict": 0,
+    "valid-typeof": 0,
+
+    "space-unary-ops": [1, {
+      "words": true,
+      "nonwords": false,
+    }],
+
+    "space-infix-ops": ["error"],
+  },
+}
+]);