code: function overrideJest({ plugin, options }, cracoConfig, jestConfig, context) {
      if (isFunction(plugin.overrideJestConfig)) {
          const resultingConfig = plugin.overrideJestConfig({
              cracoConfig: cracoConfig,
              jestConfig: jestConfig,
              pluginOptions: options,
              context: context
          });
  
          if (!resultingConfig) {
              throw new Error("craco: Plugin returned an undefined Jest config.");
          }
      }
  
      log("Overrided Jest config with plugin.");
  
      return jestConfig;
  }
docs: **********  Jest Config  ******************