config-overrides.js

const loaderUtils = require("loader-utils");
const path = require("path");

const ruleChildren = loader =>
  loader.use ||
  loader.oneOf ||
  (Array.isArray(loader.loader) && loader.loader) ||
  [];

const findIndexAndRules = (rulesSource, ruleMatcher) => {
  let result = undefined;
  const rules = Array.isArray(rulesSource)
    ? rulesSource
    : ruleChildren(rulesSource);
  rules.some(
    (rule, index) =>
      (result = ruleMatcher(rule)
        ? { index, rules }
        : findIndexAndRules(ruleChildren(rule), ruleMatcher))
  );
  return result;
};

const findRule = (rulesSource, ruleMatcher) => {
  const { index, rules } = findIndexAndRules(rulesSource, ruleMatcher);
  return rules[index];
};

const cssRuleMatcher = rule =>
  rule.test && String(rule.test) === String(/\.module\.(scss|sass)$/);

const getLocalIdent = env => (context, localIdentName, localName, options) => {
  // Use the filename or folder name, based on some uses the index.js / index.module.(css|scss|sass) project style
  const fileNameOrFolder = context.resourcePath.match(
    /index\.module\.(css|scss|sass)$/
  )
    ? "[folder]"
    : "[name]";

  // Create a hash based on a the file location and class name. Will be unique across a project, and close to globally unique.
  let hash = "";

  do {
    hash = loaderUtils.getHashDigest(
      path.posix.relative(context.rootContext, context.resourcePath) +
        localName +
        hash,
      "md5",
      "base64",
      5
    );
  } while (!isNaN(hash[0]));

  // Use loaderUtils to find the file or folder name
  let className = loaderUtils.interpolateName(
    context,
    env === "development"
      ? hash.replace("-", "")
      : fileNameOrFolder + "_" + localName + "__" + hash,
    options
  );

  // remove the .module that appears in every classname when based on the file.
  return className.replace(".module_", "_");
};

module.exports = (config, env) => {
  const cssRule = findRule(config.module.rules, cssRuleMatcher);

  cssRule.use.forEach(u => {
    if (!u.options) {
      return;
    }

    if (u.options.getLocalIdent) {
      u.options.getLocalIdent = getLocalIdent(env);
    }
  });

  return config;
};

gistfile1.txt

"react-app-rewired"