esbuild

plugins.js

const envPlugin = {
    name: "env",
    setup(build) {
        // Intercept import paths called "env" so esbuild doesn't attempt
        // to map them to a file system location. Tag them with the "env-ns"
        // namespace to reserve them for this plugin.
        build.onResolve({ filter: /^env$/ }, (args) => ({
            path: args.path,
            namespace: "env-ns",
        }));

        // Load paths tagged with the "env-ns" namespace and behave as if
        // they point to a JSON file containing the environment variables.
        build.onLoad({ filter: /.*/, namespace: "env-ns" }, () => ({
            contents: JSON.stringify(process.env),
            loader: "json",
        }));
    },
};

const copyStaticFiles = (options = {}) => ({
    name: "copy-static-files",
    setup(build) {
        let src = options.src || "./static";
        let dest = options.dest || "../public";

        build.onEnd(() =>
            fs.cpSync(src, dest, {
                dereference: options.dereference || true,
                errorOnExist: options.errorOnExist || false,
                filter: options.filter || filter,
                force: options.force || true,
                preserveTimestamps: options.preserveTimestamps || true,
                recursive: options.recursive || true,
            })
        );
    },
});