export default function reducer()

in src/amo/reducers/categories.js [91:137]
37 lines of code
6 McCabe index (conditional complexity)

export default function reducer(
  // eslint-disable-next-line default-param-last
  state: CategoriesState = initialState,
  action: Action,
): CategoriesState {
  switch (action.type) {
    case FETCH_CATEGORIES:
      return { ...initialState, loading: true };
    case LOAD_CATEGORIES: {
      const { payload } = action;

      const categoryList = createEmptyCategoryList();

      payload.results.forEach((category) => {
        // This category has no data, so skip it.
        if (!category) {
          // eslint-disable-next-line amo/only-log-strings
          log.warn('category was falsey: %o', category);
          return;
        }

        if (!categoryList[category.type]) {
          log.warn(oneLine`add-on category for unknown add-on type
              "${category.type}" received from API.`);
          return;
        }

        categoryList[category.type].push(category);
      });

      const categories: CategoryMapType = {};
      Object.keys(categoryList).forEach((addonType) => {
        // $FlowIgnore: flow can't be sure that the reduce result match ExternalCategory definition, let's trust the test coverage here.
        categories[addonType] = categoryList[addonType]
          .sort((a, b) => a.name.localeCompare(b.name))
          .reduce((object, value) => ({ ...object, [value.slug]: value }), {});
      });

      return {
        categories,
        loading: false,
      };
    }
    default:
      return state;
  }
}