Config for linear updaters. (#5222)

tests/cpp/c_api/test_c_api.cc

@@ -112,7 +112,7 @@ TEST(c_api, ConfigIO) {
   delete pp_dmat;
 }
 
-TEST(c_api, Json_ModelIO) {
+TEST(c_api, JsonModelIO) {
   size_t constexpr kRows = 10;
   dmlc::TemporaryDirectory tempdir;
 

tests/cpp/gbm/test_gblinear.cc

@@ -16,7 +16,7 @@
 namespace xgboost {
 namespace gbm {
 
-TEST(GBLinear, Json_IO) {
+TEST(GBLinear, JsonIO) {
   size_t constexpr kRows = 16, kCols = 16;
 
   LearnerModelParam param;

tests/cpp/gbm/test_gbtree.cc

@@ -103,8 +103,8 @@ TEST(GBTree, ChoosePredictor) {
 }
 #endif  // XGBOOST_USE_CUDA
 
-// Some other parts of test are in `Tree.Json_IO'.
-TEST(GBTree, Json_IO) {
+// Some other parts of test are in `Tree.JsonIO'.
+TEST(GBTree, JsonIO) {
   size_t constexpr kRows = 16, kCols = 16;
 
   LearnerModelParam mparam;
@@ -143,7 +143,7 @@ TEST(GBTree, Json_IO) {
   ASSERT_EQ(get<String>(j_train_param["num_parallel_tree"]), "1");
 }
 
-TEST(Dart, Json_IO) {
+TEST(Dart, JsonIO) {
   size_t constexpr kRows = 16, kCols = 16;
 
   LearnerModelParam mparam;

tests/cpp/linear/test_json_io.h

@@ -0,0 +1,41 @@
+/*!
+ * Copyright 2020 XGBoost contributors
+ */
+#ifndef XGBOOST_TEST_JSON_IO_H_
+#define XGBOOST_TEST_JSON_IO_H_
+
+#include <xgboost/linear_updater.h>
+#include <xgboost/json.h>
+#include <string>
+#include "../helpers.h"
+#include "../../../src/gbm/gblinear_model.h"
+
+namespace xgboost {
+inline void TestUpdaterJsonIO(std::string updater_str) {
+  auto runtime = xgboost::CreateEmptyGenericParam(GPUIDX);
+  Json config_0 {Object() };
+
+  {
+    auto updater = std::unique_ptr<xgboost::LinearUpdater>(
+        xgboost::LinearUpdater::Create(updater_str, &runtime));
+    updater->Configure({{"eta", std::to_string(3.14)}});
+    updater->SaveConfig(&config_0);
+  }
+
+  {
+    auto updater = std::unique_ptr<xgboost::LinearUpdater>(
+        xgboost::LinearUpdater::Create(updater_str, &runtime));
+    updater->LoadConfig(config_0);
+    Json config_1 { Object() };
+    updater->SaveConfig(&config_1);
+
+    ASSERT_EQ(config_0, config_1);
+    auto eta = atof(get<String const>(config_1["linear_train_param"]["eta"]).c_str());
+    ASSERT_NEAR(eta, 3.14, kRtEps);
+  }
+
+}
+
+}  // namespace xgboost
+
+#endif  // XGBOOST_TEST_JSON_IO_H_

tests/cpp/linear/test_linear.cc

@@ -5,12 +5,13 @@
 #include <xgboost/gbm.h>
 
 #include "../helpers.h"
-
+#include "test_json_io.h"
 #include "../../../src/gbm/gblinear_model.h"
+#include "xgboost/base.h"
 
 namespace xgboost {
 
-TEST(Linear, shotgun) {
+TEST(Linear, Shotgun) {
   size_t constexpr kRows = 10;
   size_t constexpr kCols = 10;
 
@@ -45,6 +46,10 @@ TEST(Linear, shotgun) {
   delete pp_dmat;
 }
 
+TEST(Shotgun, JsonIO) {
+  TestUpdaterJsonIO("shotgun");
+}
+
 TEST(Linear, coordinate) {
   size_t constexpr kRows = 10;
   size_t constexpr kCols = 10;
@@ -72,4 +77,8 @@ TEST(Linear, coordinate) {
   delete pp_dmat;
 }
 
+TEST(Coordinate, JsonIO){
+  TestUpdaterJsonIO("coord_descent");
+}
+
 }  // namespace xgboost

tests/cpp/linear/test_linear.cu

@@ -3,6 +3,7 @@
 #include <xgboost/gbm.h>
 
 #include "../helpers.h"
+#include "test_json_io.h"
 #include "../../../src/gbm/gblinear_model.h"
 
 namespace xgboost {
@@ -33,4 +34,8 @@ TEST(Linear, GPUCoordinate) {
 
   delete mat;
 }
+
+TEST(GPUCoordinate, JsonIO) {
+  TestUpdaterJsonIO("gpu_coord_descent");
+}
 }  // namespace xgboost

tests/cpp/objective/test_ranking_obj.cc

@@ -36,7 +36,7 @@ TEST(Objective, DeclareUnifiedTest(PairwiseRankingGPair)) {
   ASSERT_NO_THROW(obj->DefaultEvalMetric());
 }
 
-TEST(Objective, DeclareUnifiedTest(NDCG_Json_IO)) {
+TEST(Objective, DeclareUnifiedTest(NDCG_JsonIO)) {
   xgboost::GenericParameter tparam;
   tparam.UpdateAllowUnknown(Args{});
 

tests/cpp/test_learner.cc

@@ -134,7 +134,7 @@ TEST(Learner, Configuration) {
   }
 }
 
-TEST(Learner, Json_ModelIO) {
+TEST(Learner, JsonModelIO) {
   // Test of comparing JSON object directly.
   size_t constexpr kRows = 8;
   int32_t constexpr kIters = 4;

tests/cpp/tree/test_tree_model.cc

@@ -220,7 +220,7 @@ TEST(Tree, DumpDot) {
   ASSERT_NE(str.find(R"(graph [ bgcolor="#FFFF00" ])"), std::string::npos);
 }
 
-TEST(Tree, Json_IO) {
+TEST(Tree, JsonIO) {
   RegTree tree;
   tree.ExpandNode(0, 0, 0.0f, false, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
   Json j_tree{Object()};