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var R = require('../source');var eq = require('./shared/eq');

describe('composeWith', function() {
  it('performs right-to-left function composition with function applying', function() {    //  f :: (String, Number?) -> ([Number] -> [Number])    var f = R.composeWith(function(f, res) {      return f(res);    })([R.map, R.multiply, parseInt]);
    eq(f.length, 2);    eq(f('10')([1, 2, 3]), [10, 20, 30]);    eq(f('10', 2)([1, 2, 3]), [2, 4, 6]);  });
  it('performs right-to-left function while not nil result', function() {    var isOdd = R.flip(R.modulo)(2);    var composeWhenNotNil = R.composeWith(function(f, res) {      return R.isNil(res) ? null : f(res);    });
    var f = composeWhenNotNil([R.inc, R.ifElse(isOdd, R.identity, R.always(null)), parseInt]);
    eq(f.length, 2);    eq(f('1'), 2);    eq(f('2'), null);  });
  it('performs right-to-left function using promise chaining', function() {    var then = function(f, p) { return p.then(f); };    var composeP = R.composeWith(then);    var toListPromise = function(a) { return new Promise(function(res) { res([a]); }); };    var doubleListPromise = function(a) { return new Promise(function(res) { res(R.concat(a, a)); }); };    var f = composeP([      doubleListPromise,      toListPromise    ]);
    return f(1)      .then(function(res) {        eq(res, [1, 1]);      });  });
});