pairwise.md

pairwise decorator

The pairwise decorator returns the result by the previous step function and the result of current step that is decorated. Both are returned inside an array. You can explore the source code here.

Example usage

Here we are just adding the imdb id to a given movie object.

  const { pairwise, step, pipe } =  require('@axa/bautajs-core');

    const getMovie = step(() => ({ name: 'star wars' }));
    const getMovieImdbIdAsync = step(() => Promise.resolve('imdb12354'));

    const pipeline = pipe(
      getMovie,
      pairwise(getMovieImdbIdAsync),
      ([movie, imdbId]) => ({
      ...movie,
      imdb_id: imdbId
    }));

Error handling

Errors thrown inside pairwise StepFunctions are propagated as any other StepFunction. In the example above in case that getMovieImdbIdAsync throws an error, the pipeline will stop there and the error will be propagated. You can learn about step and pipelines handling errors here.