.babelrc

{
  "presets": [
    "@babel/preset-env",
    "@babel/preset-react"
  ],
  "plugins": [
    ["prismjs", {
        "languages": ["javascript", "clike", "reason", "java"],
        "plugins": ["line-numbers"],
        "css": true
    }],

    // // Stage 1
    // "@babel/plugin-proposal-export-default-from",
    // "@babel/plugin-proposal-logical-assignment-operators",
    // ["@babel/plugin-proposal-optional-chaining", { "loose": false }],
    // ["@babel/plugin-proposal-pipeline-operator", { "proposal": "minimal" }],
    // ["@babel/plugin-proposal-nullish-coalescing-operator", { "loose": false }],
    // "@babel/plugin-proposal-do-expressions",

    // // Stage 2
    // ["@babel/plugin-proposal-decorators", { "legacy": true }],
    // "@babel/plugin-proposal-function-sent",
    // "@babel/plugin-proposal-export-namespace-from",
    // "@babel/plugin-proposal-numeric-separator",
    // "@babel/plugin-proposal-throw-expressions",

    // // Stage 3
    // "@babel/plugin-syntax-dynamic-import",
    // "@babel/plugin-syntax-import-meta",
    ["@babel/plugin-proposal-class-properties", { "loose": false }],
    // "@babel/plugin-proposal-json-strings"
  ]
}