added simple test cases

Author: mikolalysenko

test/test.js

@@ -3,9 +3,28 @@
 var tape = require('tape')
 var pack = require('ndarray-pack')
 var unpack = require('ndarray-unpack')
+var zeros = require('ndarray-scratch').zeros
 var grad = require('../fdg')
 
+function g(X, bc) {
+  var Y = pack(X)
+  var dX = grad(zeros(Y.shape.slice().concat([Y.dimension])), Y, bc)
+  var perm = [Y.dimension]
+  for(var i=0; i<Y.dimension; ++i) {
+    perm[i+1] = i
+  }
+  return unpack(dX.transpose.apply(dX, perm))
+}
+
 tape('ndarray-gradient', function(t) {
 
+  t.same(g([1,2,3], 'wrap'), [[0.5, -1, 0.5]])
+  t.same(g([1,2,3], 'clamp'), [[-0.5,-1, -0.5]])
+  t.same(g([1,2,3], 'mirror'), [[0, -1, 0]])
+
+  t.same(g([1,2], 'wrap'), [[0,0]])
+  t.same(g([1,2], 'clamp'), [[-0.5, -0.5]])
+  t.same(g([1,2], 'mirror'), [[0,0]])
+
   t.end()
 })