step-flow example

step-flow-example.js

/**
 * @file step-flow example
 * @author zdyng
 */

'use strict';

const fs = require('fs');
const path = require('path');
const md5 = require('md5');

const StepFlow = require('step-flow');
const flow = new StepFlow();

flow
  .use('read-file', readFile)
  .use('add-source-map', addSourceMap)
  .use('get-md5', getMD5)
  .use('write-file', writeFile)
  .catch(onError);

let ctx = {
  filePath: path.join(__dirname, 'test.js')
};

flow.run(ctx);

function readFile (ctx, next) {
  let {filePath} = ctx;

  // fs.readFile(filePath, 'utf-8', next);
  fs.readFile(filePath, 'utf-8', function (err, data) {
    if (err) {
      next(err);
    } else {
      ctx.fileContent = data;
      next();
    }
  });
}

function addSourceMap (ctx, next, nextTo, data) {
  // next(null, data + '\n// # sourceMappingURL=/test.js.map');

  ctx.fileContent += '\n// # sourceMappingURL=/test.js.map\n';
  next();
}

function getMD5 (ctx, next) {
  ctx.md5 = md5(ctx.fileContent);
  next();
}

function writeFile (ctx, next) {
  let newFileName = ctx.filePath.replace(/^(.*)\.([^.]+)$/, '$1' + '@' + ctx.md5 + '.$2');

  fs.writeFile(newFileName, ctx.fileContent, next);
}

function onError (err) {
  console.log('[Error]:', err);
}