Minor addition to R unit tests

R-package/tests/testthat/test_helpers.R

@@ -5,6 +5,7 @@ require(data.table)
 require(Matrix)
 require(vcd)
 
+set.seed(1994)
 data(Arthritis)
 data(agaricus.train, package='xgboost')
 df <- data.table(Arthritis, keep.rownames = F)
@@ -16,15 +17,16 @@ output_vector <- df[,Y := 0][Improved == "Marked",Y := 1][,Y]
 bst <- xgboost(data = sparse_matrix, label = output_vector, max.depth = 9,
                eta = 1, nthread = 2, nround = 10,objective = "binary:logistic")
 
-
 test_that("xgb.dump works", {
-  capture.output(print(xgb.dump(bst)))
+  dump <- xgb.dump(bst)
+  expect_equal(length(dump, 172))
 })
 
 test_that("xgb.importance works", {
-  xgb.dump(bst, 'xgb.model.dump', with.stats = T)
+  expect_true(xgb.dump(bst, 'xgb.model.dump', with.stats = T))
   importance <- xgb.importance(sparse_matrix@Dimnames[[2]], 'xgb.model.dump')
   expect_equal(dim(importance), c(7, 4))
+  expect_equal(colnames(importance), c("Feature", "Gain", "Cover", "Frequence"))
 })
 
 test_that("xgb.plot.tree works", {