s-pipe/test/range.js

Functional streams, with a lisp-inspired chaining syntax

var spipe = require('../lib');


runMocha({
  'RangeStream': {
    'returning synchronously': function() {
      equal(spipe(1, 1000)().length, 1000);
    },

    'increasing range': function() {
      deepEqual(spipe(1, 10)(), [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
    },

    'increasing range with step': function() {
      deepEqual(spipe(1, 10, 3)(), [1, 4, 7, 10]);
    },

    'decreasing range': function() {
      deepEqual(spipe(10, 1)(), [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]);
    },

    'decreasing range with step': function() {
      deepEqual(spipe(10, 1, 2)(), [10, 8, 6, 4, 2]);
    },

    'never go past the end': function() {
      deepEqual(spipe(1, 10, 6)(), [1, 7]);
      deepEqual(spipe(10, 1, 6)(), [10, 4]);
    },

    'lazily evaluate the stream': function(done) {
      var result = [];
      var stream = spipe(1, 10, 4)(false);
      stream.on('data', function(n) {
        result.push(n);
      });
      stream.on('end', function() {
        deepEqual(result, [1, 5, 9]);
        done();
      });
    },

    'only specify first argument to create ranges from 0': function() {
      deepEqual(spipe(5)(), [0, 1, 2, 3, 4, 5]);
    }
  }
});