runnel/test/runnel.js

Simple and small flow control library to execute async functions in sequence

'use strict';
/*jshint asi: true */

var test = require('tape')
  , runnel = require('..')
  , unofails
  , dosfails
  , tresfails
  , unocalled
  , doscalled
  , baddoscalled
  , trescalled
  , unocallsTwice
  ;

function uno (cb) {
  unocalled = true;
  setTimeout( 
      function () { 
        if (unofails) cb(new Error('uno failed')); 
        else cb(null, 'eins'); 
      } 
    , 10);

  if (unocallsTwice)
    setTimeout(function () { cb(null, 'eins'); } , 20);
}

function dos (resuno, cb) {
  doscalled = true;
  setTimeout( 
      function () { 
        if (dosfails) cb(new Error('dos failed')); 
        else cb(null, resuno, 'zwei'); 
      } 
    , 10);
}

function baddos (resuno, cb) {
  baddoscalled = true;
  throw new Error('dos was bad');
}

function synerror (resuno, cb) {
  var a;
  // on purpose
  aa++;
}

function tres (resuno, resdos, cb) {
  trescalled = true;
  setTimeout( 
      function () { 
        if (tresfails) cb(new Error('tres failed')); 
        else cb(null, resuno, resdos, 'drei'); 
      } 
    , 10);
}

function setup () {
  unofails = dosfails = tresfails = false;
  unocalled = doscalled = baddoscalled = trescalled = false;
  unocallsTwice = false;
}

test('\n parameter passing', function (t) {
  t.plan(4);

  setup();

  runnel(uno, dos, tres, function (err, resuno, resdos, restres) {
    t.equal(err, null, 'no error');    
    t.equal(resuno, 'eins', 'passes first param');
    t.equal(resdos, 'zwei', 'passes second param');
    t.equal(restres, 'drei', 'passes third param');
    t.end();
  });
});

test('\n functions passed as array', function (t) {
  t.plan(4);

  setup();

  runnel([uno, dos, tres, function (err, resuno, resdos, restres) {
    t.equal(err, null, 'no error');    
    t.equal(resuno, 'eins', 'passes first param');
    t.equal(resdos, 'zwei', 'passes second param');
    t.equal(restres, 'drei', 'passes third param');
    t.end();
  }]);
})


test('\n error handling: last in chain (tres) fails', function (t) {
  t.plan(7);

  setup();
  tresfails = true;

  runnel(uno, dos, tres, function (err, resuno, resdos, restres) {

  
    t.ok(/tres failed/.test(err.message), 'passes error');
    t.ok(unocalled, 'called uno');
    t.ok(doscalled, 'called dos');
    t.ok(trescalled, 'called tres');

    t.equal(resuno, undefined, 'no resuno');
    t.equal(resdos, undefined, 'no resdos');
    t.equal(restres, undefined, 'no restres');

    t.end();
  });
});

test('\n error handling: first in chain (uno) fails', function (t) {
  t.plan(7);

  setup();
  unofails = true;

  runnel(uno, dos, tres, function (err, resuno, resdos, restres) {

    t.ok(/uno failed/.test(err.message), 'passes error');
    t.ok(unocalled, 'called uno');
    t.notOk(doscalled, 'not called dos');
    t.notOk(trescalled, 'not called tres');

    t.equal(resuno, undefined, 'no resuno');
    t.equal(resdos, undefined, 'no resdos');
    t.equal(restres, undefined, 'no restres');

    t.end();
  });
});

test('\n error handling: first in chain (uno) fails and calls again afterwards', function (t) {
  t.plan(8);

  setup();
  unofails = true;
  unocallsTwice = true;
  var count = 0
    , keptErr
    , keptResuno
    , keptResdos
    , keptRestres
    ;

  runnel(uno, dos, tres, function (err, resuno, resdos, restres) {
    count++;
    if (err) keptErr = err;

    keptResuno = resuno;
    keptResdos = resdos;
    keptRestres = restres;
  });

  // Last callback would have happened after 20 + 10 + 10 = 40ms
  setTimeout(
      function () {

        t.equal(count, 1, 'runnel called back only once');
        t.ok(/uno failed/.test(keptErr.message), 'passes error');
        t.ok(unocalled, 'called uno');
        t.notOk(doscalled, 'not called dos');
        t.notOk(trescalled, 'not called tres');

        t.equal(keptResuno, undefined, 'no resuno');
        t.equal(keptResdos, undefined, 'no resdos');
        t.equal(keptRestres, undefined, 'no restres');

        t.end();
      }
    , 50);

});

test('\n 0 arguments', function (t) {
  setup();
  t.plan(1);
  t.throws(function () { runnel(); }, { name: 'Error', message: 'Give runnel at least 2 functions to do any work.' });
});

test('\n 1 argument', function (t) {
  setup();
  t.plan(1);
  t.throws(function () { runnel(); }, { name: 'Error', message: 'Give runnel at least 2 functions to do any work.' });
});

test('\n 3rd argument not a function', function (t) {
  setup();
  t.plan(1);
  function f () {}
  t.throws(function () { runnel(f, f, "duh"); }, { name: 'Error', message: 'All arguments passed to runnel need to be a function. Argument at (zero based) position 2 is not.' });
});

test('\n second callback throws', function (t) {
  
  setup();

  runnel(uno, baddos, tres, function (err, resuno, resdos, restres) {

    t.ok(/dos was bad/.test(err.message), 'passes error');
    t.ok(unocalled, 'called uno');
    t.ok(baddoscalled, 'called baddos');
    t.notOk(trescalled, 'not called tres');

    t.equal(resuno, undefined, 'no resuno');
    t.equal(resdos, undefined, 'no resdos');
    t.equal(restres, undefined, 'no restres');

    t.end();
  });
})

test('\n second callback has syntax error', function (t) {
  
  setup();

  runnel(uno, synerror, tres, function (err) {
    if (!process.browser)
      // no way to cover all possible error messages for each browser
      t.ok(/aa is not defined/.test(err.message), 'passes syntax error');
    else
      t.ok(err, 'passes syntax error')

    t.ok(unocalled, 'called uno');
    t.notOk(trescalled, 'not called tres');

    t.end();
  });
})