zulip/tools/webpack-helpers.ts

import { basename, resolve } from 'path';
import { RuleSetRule, RuleSetUseItem } from 'webpack';

export const cacheLoader: RuleSetUseItem = {
    loader: 'cache-loader',
    options: {
        cacheDirectory: resolve(__dirname, '../var/webpack-cache'),
    },
};

/* Return expose-loader format to the config
    For example
    [
        // Exposes 'my_module' as the name
        {path: './folder/my_module.js'},

        // Exposes 'my_custom_name'
        {path: './folder/my_module.js', name: 'my_custom_name'},

        // Exposes 'name1' and 'name2'
        {path: './folder/my_module.js', name: ['name1', 'name2']}
    ]
*/
interface ExportLoaderOptions {
    path: string;
    name?: string | string[];
}
function getExposeLoaders(optionsArr: ExportLoaderOptions[]): RuleSetRule[] {
    const exposeLoaders = [];
    for (var loaderEntry of optionsArr) {
        const path = loaderEntry.path;
        let name = "";
        const useArr = [cacheLoader];
        // If no name is provided, infer it
        if (!loaderEntry.name) {
            name = basename(path, '.js');
            useArr.push({loader: 'expose-loader', options: name});
        } else {
            // If name is an array
            if (Array.isArray(loaderEntry.name)) {
                for (var exposeName of loaderEntry.name) {
                    useArr.push({loader: 'expose-loader', options: exposeName});
                }
            // If name is a string
            } else {
                useArr.push({loader: 'expose-loader', options: loaderEntry.name});
            }
        }
        exposeLoaders.push({
            test: require.resolve(path),
            use: useArr,
        });
    }
    return exposeLoaders;
}
export {
    getExposeLoaders,
};