[R] allow using seed with regular RNG (#10029)

R-package/tests/testthat/test_basic.R

@@ -778,3 +778,66 @@ test_that("DMatrix field are set to booster when training", {
   expect_equal(getinfo(model_feature_types, "feature_type"), c("q", "c", "q"))
   expect_equal(getinfo(model_both, "feature_type"), c("q", "c", "q"))
 })
+
+test_that("Seed in params override PRNG from R", {
+  set.seed(123)
+  model1 <- xgb.train(
+    data = xgb.DMatrix(
+      agaricus.train$data,
+      label = agaricus.train$label, nthread = 1L
+    ),
+    params = list(
+      objective = "binary:logistic",
+      max_depth = 3L,
+      subsample = 0.1,
+      colsample_bytree = 0.1,
+      seed = 111L
+    ),
+    nrounds = 3L
+  )
+
+  set.seed(456)
+  model2 <- xgb.train(
+    data = xgb.DMatrix(
+      agaricus.train$data,
+      label = agaricus.train$label, nthread = 1L
+    ),
+    params = list(
+      objective = "binary:logistic",
+      max_depth = 3L,
+      subsample = 0.1,
+      colsample_bytree = 0.1,
+      seed = 111L
+    ),
+    nrounds = 3L
+  )
+
+  expect_equal(
+    xgb.save.raw(model1, raw_format = "json"),
+    xgb.save.raw(model2, raw_format = "json")
+  )
+
+  set.seed(123)
+  model3 <- xgb.train(
+    data = xgb.DMatrix(
+      agaricus.train$data,
+      label = agaricus.train$label, nthread = 1L
+    ),
+    params = list(
+      objective = "binary:logistic",
+      max_depth = 3L,
+      subsample = 0.1,
+      colsample_bytree = 0.1,
+      seed = 222L
+    ),
+    nrounds = 3L
+  )
+  expect_false(
+    isTRUE(
+      all.equal(
+        xgb.save.raw(model1, raw_format = "json"),
+        xgb.save.raw(model3, raw_format = "json")
+      )
+    )
+  )
+})