implement culture invariant strings (dotnet#3725)

Author: srsaggam

src/mlnet/CodeGenerator/CSharp/TrainerGeneratorBase.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text;
 using Microsoft.ML.AutoML;
@@ -12,7 +13,6 @@ namespace Microsoft.ML.CLI.CodeGenerator.CSharp
 {
     /// <summary>
     /// Supports generation of code for trainers (Binary,Multi,Regression)
-    /// Ova is an exception though. Need to figure out how to tackle that.
     /// </summary>
     internal abstract class TrainerGeneratorBase : ITrainerGenerator
     {
@@ -61,17 +61,27 @@ private void Initialize(PipelineNode node)
                 if (type == typeof(bool))
                 {
                     //True to true
-                    value = ((bool)kv.Value).ToString().ToLowerInvariant();
+                    value = ((bool)kv.Value).ToString(CultureInfo.InvariantCulture).ToLowerInvariant();
                 }
                 if (type == typeof(float))
                 {
                     //0.0 to 0.0f
-                    value = ((float)kv.Value).ToString() + "f";
+                    value = ((float)kv.Value).ToString(CultureInfo.InvariantCulture) + "f";
                 }
 
-                if (type == typeof(int) || type == typeof(double) || type == typeof(long))
+                if (type == typeof(int))
                 {
-                    value = (kv.Value).ToString();
+                    value = ((int)kv.Value).ToString(CultureInfo.InvariantCulture);
+                }
+
+                if (type == typeof(double))
+                {
+                    value = ((double)kv.Value).ToString(CultureInfo.InvariantCulture);
+                }
+
+                if (type == typeof(long))
+                {
+                    value = ((long)kv.Value).ToString(CultureInfo.InvariantCulture);
                 }
 
                 if (type == typeof(string))

test/mlnet.Tests/TrainerGeneratorTests.cs

@@ -1,17 +1,41 @@
 using System.Collections.Generic;
+using System.Globalization;
+using System.Threading;
 using Microsoft.ML;
 using Microsoft.ML.AutoML;
 using Microsoft.ML.CLI.CodeGenerator.CSharp;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace mlnet.Tests
 {
-    /****************************
-     * TODO : Add all trainer tests :
-     * **************************/
     [TestClass]
     public class TrainerGeneratorTests
     {
+        [TestMethod]
+        public void CultureInvariantTest()
+        {
+
+            var context = new MLContext();
+
+            var elementProperties = new Dictionary<string, object>()
+            {
+                {"LearningRate", 0.1f },
+                {"NumberOfLeaves", 1 },
+            };
+            PipelineNode node = new PipelineNode("LightGbmBinary", PipelineNodeType.Trainer, default(string[]), default(string), elementProperties);
+            Pipeline pipeline = new Pipeline(new PipelineNode[] { node });
+
+            //Set culture to deutsch.
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE");
+
+            CodeGenerator codeGenerator = new CodeGenerator(pipeline, null, null);
+            var actual = codeGenerator.GenerateTrainerAndUsings();
+            string expectedTrainerString = "LightGbm(learningRate:0.1f,numberOfLeaves:1,labelColumnName:\"Label\",featureColumnName:\"Features\")";
+            Assert.AreEqual(expectedTrainerString, actual.Item1);
+            Assert.IsNull(actual.Item2);
+
+        }
+
         [TestMethod]
         public void LightGbmBinaryBasicTest()
         {