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

require('../env.js');

suite.addBatch({
  'diff': {
    'topic': function() {
      return jStat;
    },
    'return basic diff': function(jStat) {
      assert.deepEqual(jStat.diff([1, 2, 3]), [1, 1]);
    },
    'diff from instance': function(jStat) {
      assert.deepEqual(jStat([1, 2, 3]).diff(), [1, 1]);
    },
    'diff matrix cols': function(jStat) {
      assert.deepEqual(jStat([[1, 2], [3, 4]]).diff(), [[2], [2]]);
    }
  },
  '#diff vector': {
    'topic': function() {
      jStat([1, 2, 3]).diff(this.callback);
    },
    'diff callback': function(val, stat) {
      assert.deepEqual(val, [1, 1]);
    }
  },
  '#diff matrix cols': {
    'topic': function() {
      jStat([[1, 2], [3, 4]]).diff(this.callback);
    },
    'diff matrix cols callback': function(val, stat) {
      assert.deepEqual(val, [[2], [2]]);
    }
  }
});

suite.export(module);