cbuffer/test/accessor/sortedIndex-test.js

Circular Buffer JavaScript implementation

var vows = require('vows');
var assert = require('assert');
var suite = vows.describe('sortedIndex');

require('../env');

suite.addBatch({
  'sortedIndex': {
    'works with simple sorted case': {
      topic: function() {
        return CBuffer(1, 3, 5, 7, 11);
      },
      'no iterator provided': function(buffer) {
        assert.equal(buffer.sortedIndex(-1), 0);
        assert.equal(buffer.sortedIndex(1.5), 1);
      },
      'returns index of existing items': function(buffer) {
        assert.equal(buffer.sortedIndex(1), 0);
        assert.equal(buffer.sortedIndex(5), 2);
        assert.equal(buffer.sortedIndex(11), 4);
      },
      'around the corner': function(buffer) {
        assert.equal(buffer.sortedIndex(-1), 0);
        assert.equal(buffer.sortedIndex(12), 4);
      },
      'takes an iterator': function() {
        var buffer = CBuffer(7, 5, 11, 3, 1);
        function iter(a, b) {
          return Math.abs(a - 8) - Math.abs(b - 8);
        }
        assert.equal(buffer.sortedIndex(6, iter), 1);
      },

      'non-full circular buffer': {
        topic: function() {
          var buffer = CBuffer(20);
          buffer.push(1, 2, 3, 4, 5, 6, 7, 8);
          return buffer;
        },
        'works with partially complete buffers': function(buffer) {
          assert.equal(buffer.sortedIndex(3), 2);
          assert.equal(buffer.sortedIndex(8), 7);
        },
        'can determine postion in a fixed length buffer': function(buffer) {
          assert.equal(buffer.sortedIndex(0), 0);
          assert.equal(buffer.sortedIndex(1), 0);
          assert.equal(buffer.sortedIndex(3), 2);
          assert.equal(buffer.sortedIndex(10), 8);
        }
      },

      'supports classic repeative item case': {
        topic: function() {
          return CBuffer(0, 0, 0, 1, 1, 1, 1, 1, 1, 3);
        },
        'supports repative item': function(buffer) {
          assert.equal(buffer.sortedIndex(2), 9);
        }
      }
    },

    'handles circular cases': {
      'mid circular case': {
        topic: function() {
          var buffer = CBuffer(-1, 0, 1, 3, 5);
          buffer.push(7, 9);
          return buffer;
        },
        'simple circular buffer': function(buffer) {
          assert.equal(buffer.sortedIndex(0), 0);
          assert.equal(buffer.sortedIndex(2), 1);
          assert.equal(buffer.sortedIndex(4), 2);
          assert.equal(buffer.sortedIndex(7), 3);
          assert.equal(buffer.sortedIndex(8), 4);
          assert.equal(buffer.sortedIndex(10), 4);
        },
        'circular buffer on the pivot': function(buffer) {
          assert.equal(buffer.sortedIndex(4.999), 2);
          assert.equal(buffer.sortedIndex(5), 2);
          assert.equal(buffer.sortedIndex(6), 3);
        },
        'returns index of existing item': function(buffer) {
          assert.equal(buffer.sortedIndex(7), 3);
        }
      },

      'almost sorted data cases (1 item out of place)': {
        topic: function() {
          var buffer = CBuffer(-3, -1, 0, 1, 3, 5, 7);
          buffer.push(7, 9, 11, 13, 15, 17);
          return buffer;
        },
        'single item out of place': function(buffer) {
          assert.equal(buffer.sortedIndex(0), 0);
          assert.equal(buffer.sortedIndex(17), 6);
        }
      }
    }
  }
});

suite.export(module);