comp-undo-steps 2: Using compose to flatten things out.

comp-undo-steps-2-compose.js

const processFoo = compose(
  stepA(optionsA),
  stepB(optionsB),
  stepC(optionsC)
)(res => res);

async function handleSomeThing(ctx) {
  // Create a pctx with the original ctx and whatever else we want.
  // NOTE: in this case, we're trying to not pollute the original ctx,
  // which might be something like a Koa Context.
  const pctx = { ctx };
  const resultPctx = await processFoo(pctx);
  return resultPctx.resultFoo;
}