Improve test coverage (#694)

* Improve test coverage of ctors that take UnitSystem

* Improve test coverage of IQuantity properties

* Add more test coverage to IQuantity

CodeGen/Generators/UnitsNetGen/IQuantityTestClassGenerator.cs

@@ -0,0 +1,88 @@
+// Licensed under MIT No Attribution, see LICENSE file at the root.
+// Copyright 2013 Andreas Gullberg Larsen ([email protected]). Maintained at https://github.com/angularsen/UnitsNet.
+
+using System;
+using System.Linq;
+using CodeGen.JsonTypes;
+
+namespace CodeGen.Generators.UnitsNetGen
+{
+    internal class IQuantityTestClassGenerator : GeneratorBase
+    {
+        private readonly Quantity[] _quantities;
+
+        public IQuantityTestClassGenerator(Quantity[] quantities)
+        {
+            _quantities = quantities;
+        }
+
+        public override string Generate()
+        {
+            Writer.WL(GeneratedFileHeader);
+            Writer.WL($@"
+using System;
+using UnitsNet.Units;
+using Xunit;
+
+namespace UnitsNet.Tests
+{{
+    public partial class IQuantityTests
+    {{
+        [Fact]
+        public void From_ValueAndUnit_ReturnsQuantityWithSameValueAndUnit()
+        {{
+            void Assertion(int expectedValue, Enum expectedUnit, IQuantity quantity)
+            {{
+                Assert.Equal(expectedUnit, quantity.Unit);
+                Assert.Equal(expectedValue, quantity.Value);
+            }}
+");
+            foreach (var quantity in _quantities)
+            {
+                // Pick last one to maybe avoid getting the base unit
+                var lastUnit = quantity.Units.Last();
+
+                // Example: LengthUnit.Centimeter
+                var unitEnumNameAndValue = $"{quantity.Name}Unit.{lastUnit.SingularName}";
+                Writer.WL($@"
+            Assertion(3, {unitEnumNameAndValue}, Quantity.From(3, {unitEnumNameAndValue}));");
+            }
+            Writer.WL($@"
+        }}
+
+        [Fact]
+        public void QuantityInfo_IsSameAsStaticInfoProperty()
+        {{
+            void Assertion(QuantityInfo expected, IQuantity quantity) => Assert.Same(expected, quantity.QuantityInfo);
+");
+            foreach (var quantity in _quantities) Writer.WL($@"
+            Assertion({quantity.Name}.Info, {quantity.Name}.Zero);");
+            Writer.WL($@"
+        }}
+
+        [Fact]
+        public void Type_EqualsStaticQuantityTypeProperty()
+        {{
+            void Assertion(QuantityType expected, IQuantity quantity) => Assert.Equal(expected, quantity.Type);
+");
+            foreach (var quantity in _quantities) Writer.WL($@"
+            Assertion({quantity.Name}.QuantityType, {quantity.Name}.Zero);");
+            Writer.WL($@"
+        }}
+
+        [Fact]
+        public void Dimensions_IsSameAsStaticBaseDimensions()
+        {{
+            void Assertion(BaseDimensions expected, IQuantity quantity) => Assert.Equal(expected, quantity.Dimensions);
+");
+            foreach (var quantity in _quantities) Writer.WL($@"
+            Assertion({quantity.Name}.BaseDimensions, {quantity.Name}.Zero);");
+            Writer.WL($@"
+        }}
+    }}
+}}");
+
+            return Writer.ToString();
+        }
+    }
+}

CodeGen/Generators/UnitsNetGenerator.cs

@@ -54,6 +54,8 @@ public static void Generate(string rootDir, Quantity[] quantities)
                 Log.Information(sb.ToString());
             }
 
+            GenerateIQuantityTests(quantities, $"{testProjectDir}/GeneratedCode/IQuantityTests.g.cs");
+
             Log.Information("");
             GenerateUnitAbbreviationsCache(quantities, $"{outputDir}/UnitAbbreviationsCache.g.cs");
             GenerateQuantityType(quantities, $"{outputDir}/QuantityType.g.cs");
@@ -100,6 +102,13 @@ private static void GenerateUnitTestBaseClass(StringBuilder sb, Quantity quantit
             sb.Append("test base(OK) ");
         }
 
+        private static void GenerateIQuantityTests(Quantity[] quantities, string filePath)
+        {
+            var content = new IQuantityTestClassGenerator(quantities).Generate();
+            File.WriteAllText(filePath, content, Encoding.UTF8);
+            Log.Information("IQuantityTests.g.cs: ".PadRight(AlignPad) + "(OK)");
+        }
+
         private static void GenerateUnitAbbreviationsCache(Quantity[] quantities, string filePath)
         {
             var content = new UnitAbbreviationsCacheGenerator(quantities).Generate();

UnitsNet.Tests/IQuantityTests.cs → UnitsNet.Tests/CustomCode/IQuantityTests.cs

@@ -7,7 +7,7 @@
 
 namespace UnitsNet.Tests
 {
-    public class IQuantityTests
+    public partial class IQuantityTests
     {
         [Fact]
         public void As_GivenWrongUnitType_ThrowsArgumentException()