[R-package] [ci] cut nrounds in unit tests (#3169)

R-package/tests/testthat/test_Predictor.R

@@ -8,6 +8,7 @@ test_that("predictions do not fail for integer input", {
         data = dtrain
         , objective = "regression"
         , verbose = -1L
+        , nrounds = 3L
     )
     X_double <- X[c(1L, 51L, 101L), , drop = FALSE]
     X_integer <- X_double

R-package/tests/testthat/test_lgb.interprete.R

@@ -32,7 +32,7 @@ test_that("lgb.intereprete works as expected for binary classification", {
     model <- lgb.train(
         params = params
         , data = dtrain
-        , nrounds = 10L
+        , nrounds = 3L
     )
     num_trees <- 5L
     tree_interpretation <- lgb.interprete(
@@ -82,7 +82,7 @@ test_that("lgb.intereprete works as expected for multiclass classification", {
     model <- lgb.train(
         params = params
         , data = dtrain
-        , nrounds = 10L
+        , nrounds = 3L
         , min_data = 1L
     )
     num_trees <- 5L

R-package/tests/testthat/test_lgb.plot.importance.R

@@ -12,7 +12,7 @@ test_that("lgb.plot.importance() should run without error for well-formed inputs
         , min_data_in_leaf = 1L
         , min_sum_hessian_in_leaf = 1.0
     )
-    model <- lgb.train(params, dtrain, 10L)
+    model <- lgb.train(params, dtrain, 3L)
     tree_imp <- lgb.importance(model, percentage = TRUE)
 
     # Check that there are no plots present before plotting

R-package/tests/testthat/test_lgb.plot.interpretation.R

@@ -32,7 +32,7 @@ test_that("lgb.plot.interepretation works as expected for binary classification"
     model <- lgb.train(
         params = params
         , data = dtrain
-        , nrounds = 10L
+        , nrounds = 3L
     )
     num_trees <- 5L
     tree_interpretation <- lgb.interprete(
@@ -80,7 +80,7 @@ test_that("lgb.plot.interepretation works as expected for multiclass classificat
     model <- lgb.train(
         params = params
         , data = dtrain
-        , nrounds = 10L
+        , nrounds = 3L
         , min_data = 1L
     )
     num_trees <- 5L

R-package/tests/testthat/test_parameters.R

@@ -19,7 +19,7 @@ test_that("Feature penalties work properly", {
       , label = train$label
       , num_leaves = 5L
       , learning_rate = 0.05
-      , nrounds = 20L
+      , nrounds = 5L
       , objective = "binary"
       , feature_penalty = paste0(feature_penalties, collapse = ",")
       , metric = "binary_error"