[PTRun][UnitConverter]Preserve more significant digits (#35073)

* [PTRun][UnitConverter]Preserve more significant digits

* Use StringComparison.OrdinalIgnoreCase

src/modules/launcher/Plugins/Community.PowerToys.Run.Plugin.UnitConverter.UnitTest/UnitHandlerTests.cs

@@ -57,8 +57,8 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter.UnitTest
             var convertModel = new ConvertModel(1, "parsec", "nanometer");
             var result = UnitHandler.Convert(convertModel).Single();
             var str = result.ToString(System.Globalization.CultureInfo.InvariantCulture);
-            Assert.AreEqual(3.0857000000000004E+25, result.ConvertedValue);
+            Assert.AreEqual(3.08567758128E+25, result.ConvertedValue);
-            Assert.AreEqual("3.0857e+25 nanometer", str);
+            Assert.AreEqual("3.08567758128E+25 nanometer", str);
         }
 
         [TestMethod]
@@ -67,8 +67,8 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter.UnitTest
             var convertModel = new ConvertModel(1, "nanometer", "parsec");
             var result = UnitHandler.Convert(convertModel).Single();
             var str = result.ToString(System.Globalization.CultureInfo.InvariantCulture);
-            Assert.AreEqual(3.2408000000000005E-26, result.ConvertedValue);
+            Assert.AreEqual(3.240779289666357E-26, result.ConvertedValue);
-            Assert.AreEqual("3.2408e-26 parsec", str);
+            Assert.AreEqual("3.2407792896664E-26 parsec", str);
         }
 
         [TestMethod]
@@ -79,46 +79,13 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter.UnitTest
             Assert.AreEqual(0, results.Count());
         }
 
-        [TestMethod]
-        public void RoundZero()
-        {
-            double result = UnitHandler.Round(0.0);
-            Assert.AreEqual(0, result);
-        }
-
         [TestMethod]
         public void RoundNormalValue()
         {
-            double result = UnitHandler.Round(3.141592653589793);
+            var convertModel = new ConvertModel(3.14159265358979323, "stone", "kg");
-            Assert.AreEqual(3.1416, result);
+            var result = UnitHandler.Convert(convertModel).Single();
-        }
+            var str = result.ToString(System.Globalization.CultureInfo.InvariantCulture);
-
+            Assert.AreEqual("19.950018128979… kg", str);
-        [TestMethod]
-        public void RoundSmallValue()
-        {
-            double result = UnitHandler.Round(1.23456789012345E-16);
-            Assert.AreEqual(1.2346E-16, result);
-        }
-
-        [TestMethod]
-        public void RoundBigValue()
-        {
-            double result = UnitHandler.Round(1234567890123456.0);
-            Assert.AreEqual(1234600000000000.0, result);
-        }
-
-        [TestMethod]
-        public void RoundNegativeValue()
-        {
-            double result = UnitHandler.Round(-3.141592653589793);
-            Assert.AreEqual(-3.1416, result);
-        }
-
-        [TestMethod]
-        public void RoundNinesValue()
-        {
-            double result = UnitHandler.Round(999999999999.9998);
-            Assert.AreEqual(1000000000000.0, result);
         }
     }
 }

src/modules/launcher/Plugins/Community.PowerToys.Run.Plugin.UnitConverter/Main.cs

@@ -72,7 +72,7 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
                     {
                         try
                         {
-                            Clipboard.SetText(result.ConvertedValue.ToString(UnitConversionResult.Format, CultureInfo.CurrentCulture));
+                            Clipboard.SetText(result.ConvertedValue.ToString(UnitConversionResult.CopyFormat, CultureInfo.CurrentCulture));
                             ret = true;
                         }
                         catch (ExternalException)
@@ -104,7 +104,7 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
                     {
                         try
                         {
-                            Clipboard.SetText(result.ConvertedValue.ToString(UnitConversionResult.Format, CultureInfo.CurrentCulture));
+                            Clipboard.SetText(result.ConvertedValue.ToString(UnitConversionResult.CopyFormat, CultureInfo.CurrentCulture));
                             ret = true;
                         }
                         catch (ExternalException)

src/modules/launcher/Plugins/Community.PowerToys.Run.Plugin.UnitConverter/UnitConversionResult.cs

@@ -2,13 +2,16 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using UnitsNet;
 
 namespace Community.PowerToys.Run.Plugin.UnitConverter
 {
     public class UnitConversionResult
     {
-        public static string Format { get; set; } = "g14";
+        public static string TitleFormat { get; set; } = "G14";
+
+        public static string CopyFormat { get; set; } = "R";
 
         public double ConvertedValue { get; }
 
@@ -23,14 +26,25 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
             QuantityInfo = quantityInfo;
         }
 
-        public string ToString(System.IFormatProvider provider = null)
+        public string ToString(IFormatProvider provider = null)
         {
             if (provider == null)
             {
                 provider = System.Globalization.CultureInfo.CurrentCulture;
             }
 
-            return ConvertedValue.ToString(Format, provider) + " " + UnitName;
+            // Check if the formatted number matches the original value. If they differ, some
+            // decimal places where cut off, and therefore we add an ellipsis.
+            string formatted = ConvertedValue.ToString(TitleFormat, provider);
+
+            if (double.TryParse(formatted, provider, out double parsedNumber) &&
+                Math.Abs(ConvertedValue - parsedNumber) > double.Epsilon &&
+                !formatted.Contains('E', StringComparison.OrdinalIgnoreCase))
+            {
+                return formatted + "… " + UnitName;
+            }
+
+            return formatted + " " + UnitName;
         }
     }
 }

src/modules/launcher/Plugins/Community.PowerToys.Run.Plugin.UnitConverter/UnitHandler.cs

@@ -11,8 +11,6 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
 {
     public static class UnitHandler
     {
-        private static readonly int _roundingSignificantDigits = 4;
-
         private static readonly QuantityInfo[] _included = new QuantityInfo[]
         {
             Acceleration.Info,
@@ -59,23 +57,6 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
             return null;
         }
 
-        /// <summary>
-        /// Rounds the value to the predefined number of significant digits.
-        /// </summary>
-        /// <param name="value">Value to be rounded</param>
-        public static double Round(double value)
-        {
-            if (value == 0.0D)
-            {
-                return 0;
-            }
-
-            var power = Math.Floor(Math.Log10(Math.Abs(value)));
-            var exponent = Math.Pow(10, power);
-            var rounded = Math.Round(value / exponent, _roundingSignificantDigits) * exponent;
-            return rounded;
-        }
-
         /// <summary>
         /// Given parsed ConvertModel, computes result. (E.g "1 foot in cm").
         /// </summary>
@@ -106,7 +87,7 @@ namespace Community.PowerToys.Run.Plugin.UnitConverter
 
                 if (!double.IsNaN(convertedValue))
                 {
-                    UnitConversionResult result = new UnitConversionResult(Round(convertedValue), convertModel.ToUnit, quantityInfo);
+                    UnitConversionResult result = new UnitConversionResult(convertedValue, convertModel.ToUnit, quantityInfo);
                     results.Add(result);
                 }
             }