How to apply antd dark theme for a React App?

The previous answers weren't working for me. This is what worked for me if it helps anybody else. I think it's due to the new less loader version and/or a change in how antd is packaged (I am really not sure).

const { getThemeVariables } = require("antd/dist/theme");
const { override, fixBabelImports, addLessLoader } = require("customize-cra");

module.exports = override(
  fixBabelImports("import", {
    libraryName: "antd",
    libraryDirectory: "es",
    style: true,
  }),
  addLessLoader({
    lessOptions: {
      javascriptEnabled: true,
      modifyVars: {
        ...getThemeVariables({
          dark: true,
          compact: true,  // optional
        }),
      },
    },
  })
);

The code is destructuring the default export when the default export is the object with the variables. Therefore, it should be:

const darkTheme = require('@ant-design/dark-theme').default;
const { override, fixBabelImports, addLessLoader } = require('customize-cra');

module.exports = override(
  fixBabelImports('import', {
    libraryName: 'antd',
    libraryDirectory: 'es',
    style: true,
  }),
  addLessLoader({
    javascriptEnabled: true,
    modifyVars: darkTheme
  }),
);

If you console log darkTheme variable which has been imported, all the styling variables are present within darkTheme.default object. I have implemented their aliyum-theme.

So for you code to work, you need to change modifyVars within config-overrides.js file to

const { darkTheme } = require('@ant-design/dark-theme');
const { override, fixBabelImports, addLessLoader } = require('customize-cra');

module.exports = override(
  fixBabelImports('import', {
    libraryName: 'antd',
    libraryDirectory: 'es',
    style: true,
  }),
  addLessLoader({
    javascriptEnabled: true,
    modifyVars: {...darkTheme.default}
  }),
);

ProTip: To override darkTheme within the application, you can create your own javascript file and import it within config-overrides.js file and destructure within modifyVars

The solution that worked for me was a combination of both @JoseFelix and @Anujs answers. Thank you both for the answers:

const darkTheme = require('@ant-design/dark-theme');
const { override, fixBabelImports, addLessLoader } = require('customize-cra');

module.exports = override(
  fixBabelImports('import', {
    libraryName: 'antd',
    libraryDirectory: 'es',
    style: true,
  }),
  addLessLoader({
    javascriptEnabled: true,
    modifyVars: darkTheme.default
  }),
);