npm distribution of dprint-plugin-dockerfile.
Use this with @dprint/formatter or just use @dprint/formatter and download the dprint-plugin-dockerfile Wasm file.
import { getPath } from "@dprint/dockerfile";
import { createFromBuffer } from "@dprint/formatter";
import * as fs from "fs";
const buffer = fs.readFileSync(getPath());
const formatter = createFromBuffer(buffer);
console.log(formatter.formatText("test.dockerfile", "RUN /bin/bash"));