Update the UnitRelations.json (#1453)

As per my comments from #1200 here are the proposed modifications to the
operators:
- [x] adding an `Inverse` relation between `Density` and
`SpecificVolume` (replacing the existing multiplication)
- [x] adding standard multiplication for `MolarEnergy.JoulePerMole *
AmountOfSubstance.Mole` (returning `Energy.Joule`)
- [x] adding standard multiplication for `Illuminance.Lux *
Area.SquareMeter` (returning `LuminousFlux.Lumen`)
- [x] `TemperatureDelta.Kelvin *
CoefficientOfThermalExpansion.PerKelvin` now returns a `Ratio` (instead
of a `double`)
- [x] added the `-- NoInferredDivision` to the
`KinematicViscosity.SquareMeterPerSecond * Duration.Second` operator (as
the opposite of the relation was `Area / Duration` ->
`KinematicViscosity` 😏 )
- [x] added the `-- NoInferredDivision` to the `Area.SquareMeter *
ReciprocalArea.InverseSquareMeter` operator (as the opposite of the
relation was `Ratio / Area` -> `InverseArea` does not appear intuitive )
- [x] change the multiplication units (using the `BaseUnit`) for the
`Mass.Kilogram = AmountOfSubstance.Mole * MolarMass.KilogramPerMole`
- [x] change the multiplication units (using the `BaseUnit`) for the
`AmountOfSubstance.Mole = MolarFlow.MolePerSecond * Duration.Second`

I've included tests for **_all_** operators from the affected classes
(_most operators, introduced with the `UnitRelations.json` were never
covered by tests_).

PS There are still many operators not covered by tests, but I'd rather
finish them later (_hopefully once we no longer have to worry about
rounding errors_).

---------

Co-authored-by: Andreas Gullberg Larsen <[email protected]>

Common/UnitRelations.json

@@ -1,24 +1,24 @@
 [
   "1 = Area.SquareMeter * ReciprocalArea.InverseSquareMeter",
+  "1 = Density.KilogramPerCubicMeter * SpecificVolume.CubicMeterPerKilogram",
   "1 = ElectricResistivity.OhmMeter * ElectricConductivity.SiemensPerMeter",
   "1 = Length.Meter * ReciprocalLength.InverseMeter",
   "Acceleration.MeterPerSecondSquared = Jerk.MeterPerSecondCubed * Duration.Second",
-  "AmountOfSubstance.Kilomole = MolarFlow.KilomolePerSecond * Duration.Second",
+  "AmountOfSubstance.Mole = MolarFlow.MolePerSecond * Duration.Second",
   "AmountOfSubstance.Mole = Molarity.MolePerCubicMeter * Volume.CubicMeter",
   "Angle.Radian = RotationalSpeed.RadianPerSecond * Duration.Second",
-  "Area.SquareMeter = KinematicViscosity.SquareMeterPerSecond * Duration.Second",
+  "Area.SquareMeter = KinematicViscosity.SquareMeterPerSecond * Duration.Second -- NoInferredDivision",
   "Area.SquareMeter = Length.Meter * Length.Meter",
   "Area.SquareMeter = Volume.CubicMeter * ReciprocalLength.InverseMeter",
   "AreaMomentOfInertia.MeterToTheFourth = Volume.CubicMeter * Length.Meter",
-  "double = Density.KilogramPerCubicMeter * SpecificVolume.CubicMeterPerKilogram",
   "double = SpecificEnergy.JoulePerKilogram * BrakeSpecificFuelConsumption.KilogramPerJoule",
-  "double = TemperatureDelta.Kelvin * CoefficientOfThermalExpansion.PerKelvin",
   "DynamicViscosity.NewtonSecondPerMeterSquared = Density.KilogramPerCubicMeter * KinematicViscosity.SquareMeterPerSecond",
   "ElectricCharge.AmpereHour = ElectricCurrent.Ampere * Duration.Hour",
   "ElectricCurrent.Ampere = ElectricCurrentGradient.AmperePerSecond * Duration.Second",
   "ElectricPotential.Volt = ElectricCurrent.Ampere * ElectricResistance.Ohm",
   "Energy.Joule = ElectricPotential.Volt * ElectricCharge.Coulomb",
   "Energy.Joule = EnergyDensity.JoulePerCubicMeter * Volume.CubicMeter",
+  "Energy.Joule = MolarEnergy.JoulePerMole * AmountOfSubstance.Mole",
   "Energy.Joule = Power.Watt * Duration.Second",
   "Energy.Joule = SpecificEnergy.JoulePerKilogram * Mass.Kilogram",
   "Energy.Joule = TemperatureDelta.Kelvin * Entropy.JoulePerKelvin",
@@ -35,8 +35,9 @@
   "Length.Meter = Speed.MeterPerSecond * Duration.Second",
   "Length.Meter = Volume.CubicMeter * ReciprocalArea.InverseSquareMeter",
   "LinearDensity.KilogramPerMeter = Area.SquareMeter * Density.KilogramPerCubicMeter",
+  "LuminousFlux.Lumen = Illuminance.Lux * Area.SquareMeter",
   "LuminousIntensity.Candela = Luminance.CandelaPerSquareMeter * Area.SquareMeter",
-  "Mass.Gram = AmountOfSubstance.Mole * MolarMass.GramPerMole",
+  "Mass.Kilogram = AmountOfSubstance.Mole * MolarMass.KilogramPerMole",
   "Mass.Kilogram = AreaDensity.KilogramPerSquareMeter * Area.SquareMeter",
   "Mass.Kilogram = Density.KilogramPerCubicMeter * Volume.CubicMeter",
   "Mass.Kilogram = LinearDensity.KilogramPerMeter * Length.Meter",
@@ -62,7 +63,8 @@
   "Pressure.NewtonPerSquareMeter = ForcePerLength.NewtonPerMeter * ReciprocalLength.InverseMeter",
   "Pressure.Pascal = PressureChangeRate.PascalPerSecond * Duration.Second",
   "Pressure.Pascal = SpecificWeight.NewtonPerCubicMeter * Length.Meter",
-  "Ratio.DecimalFraction = Area.SquareMeter * ReciprocalArea.InverseSquareMeter",
+  "Ratio.DecimalFraction = Area.SquareMeter * ReciprocalArea.InverseSquareMeter -- NoInferredDivision",
+  "Ratio.DecimalFraction = TemperatureDelta.Kelvin * CoefficientOfThermalExpansion.PerKelvin -- NoInferredDivision",
   "ReciprocalArea.InverseSquareMeter = ReciprocalLength.InverseMeter * ReciprocalLength.InverseMeter",
   "ReciprocalLength.InverseMeter = Length.Meter * ReciprocalArea.InverseSquareMeter",
   "RotationalStiffness.NewtonMeterPerRadian = RotationalStiffnessPerLength.NewtonMeterPerRadianPerMeter * Length.Meter",

UnitsNet.Tests/CustomCode/AmountOfSubstanceTests.cs

@@ -66,8 +66,8 @@ public void NumberOfParticlesInTwoMolesIsDoubleAvogadroConstant()
 
         [Theory]
         [InlineData(10, AmountOfSubstanceUnit.Mole,
-                    KnownQuantities.MolarMassOfOxygen, MolarMassUnit.GramPerMole,
-                    10 * KnownQuantities.MolarMassOfOxygen, MassUnit.Gram)]     // 10 Moles of Oxygen weight 10 times as much as 1 Mole of Oxygen (MolarMass)
+            KnownQuantities.MolarMassOfOxygen, MolarMassUnit.GramPerMole,
+            10 * KnownQuantities.MolarMassOfOxygen, MassUnit.Gram)] // 10 Moles of Oxygen weight 10 times as much as 1 Mole of Oxygen (MolarMass)
         public void MassFromAmountOfSubstanceAndMolarMass(
             double amountOfSubstanceValue, AmountOfSubstanceUnit amountOfSubstanceUnit,
             double molarMassValue, MolarMassUnit molarMassUnit,
@@ -83,9 +83,9 @@ public void MassFromAmountOfSubstanceAndMolarMass(
 
         [Theory]
         [InlineData(5, MassUnit.Gram,
-                    KnownQuantities.MolarMassHClInGramsPerMole, MolarMassUnit.GramPerMole,
-                    1.2, VolumeUnit.Liter,
-                    0.1142805, MolarityUnit.MolePerLiter)]     // molarity(HCl) = 5g / (1.2L * 36.46) = 0.114 mol/l = 0.114 M
+            KnownQuantities.MolarMassHClInGramsPerMole, MolarMassUnit.GramPerMole,
+            1.2, VolumeUnit.Liter,
+            0.1142805, MolarityUnit.MolePerLiter)] // molarity(HCl) = 5g / (1.2L * 36.46) = 0.114 mol/l = 0.114 M
         public void MolarityFromComponentMassAndSolutionVolume(
             double componentMassValue, MassUnit componentMassUnit,
             double componentMolarMassValue, MolarMassUnit componentMolarMassUnit,
@@ -104,9 +104,9 @@ public void MolarityFromComponentMassAndSolutionVolume(
 
         [Theory]
         [InlineData(5, MassUnit.Gram,
-                    KnownQuantities.MolarMassHClInGramsPerMole, MolarMassUnit.GramPerMole,
-                    0.1142805, MolarityUnit.MolePerLiter,
-                    1.2, VolumeUnit.Liter)]     // 1.2 L of solution required for obtaining 0.1142805 Moles/L from 5g HCl
+            KnownQuantities.MolarMassHClInGramsPerMole, MolarMassUnit.GramPerMole,
+            0.1142805, MolarityUnit.MolePerLiter,
+            1.2, VolumeUnit.Liter)] // 1.2 L of solution required for obtaining 0.1142805 Moles/L from 5g HCl
         public void VolumeSolutionFromComponentMassAndDesiredConcentration(
             double componentMassValue, MassUnit componentMassUnit,
             double componentMolarMassValue, MolarMassUnit componentMolarMassUnit,
@@ -122,5 +122,38 @@ public void VolumeSolutionFromComponentMassAndDesiredConcentration(
 
             AssertEx.EqualTolerance(expectedSolutionVolumeValue, volumeSolution.As(expectedSolutionVolumeUnit), tolerence);
         }
+
+        [Fact]
+        public void From_Mass_And_MolarMass_ReturnsTheMassDividedByTheMolarMass()
+        {
+            var mass = Mass.From(10, MassUnit.Gram);
+            var molarMass = MolarMass.From(2, MolarMassUnit.GramPerMole);
+            var expectedAmountOfSubstance = AmountOfSubstance.From(5, AmountOfSubstanceUnit.Mole);
+
+            var amountOfSubstance = AmountOfSubstance.FromMass(mass, molarMass);
+
+            Assert.Equal(expectedAmountOfSubstance, amountOfSubstance);
+        }
+
+        [Fact]
+        public void Multiplying_AmountOfSubstance_By_MolarEnergy_ReturnsEnergy()
+        {
+            Energy energy = AmountOfSubstance.FromMoles(5) * MolarEnergy.FromJoulesPerMole(10);
+            Assert.Equal(Energy.FromJoules(50), energy);
+        }
+
+        [Fact]
+        public void Dividing_AmountOfSubstance_By_MolarFlow_Returns_Duration()
+        {
+            var duration = AmountOfSubstance.FromMoles(10) / MolarFlow.FromMolesPerSecond(2);
+            Assert.Equal(Duration.FromSeconds(5), duration);
+        }
+
+        [Fact]
+        public void Dividing_AmountOfSubstance_By_Duration_Returns_MolarFlow()
+        {
+            MolarFlow molarFlow = AmountOfSubstance.FromMoles(10) / Duration.FromSeconds(5);
+            Assert.Equal(MolarFlow.FromMolesPerSecond(2), molarFlow);
+        }
     }
 }

UnitsNet.Tests/CustomCode/AreaTests.cs

@@ -145,5 +145,61 @@ public void AreaTimesReciprocalAreaEqualsRatio()
             Ratio ratio = Area.FromSquareMeters(0.5) * ReciprocalArea.FromInverseSquareMeters(10);
             Assert.Equal(5.0, ratio.Value);
         }
+
+        [Fact]
+        public void AreaTimesIlluminanceEqualsLuminousFlux()
+        {
+            LuminousFlux luminousFlux = Area.FromSquareMeters(5) * Illuminance.FromLux(10);
+            Assert.Equal(LuminousFlux.FromLumens(50), luminousFlux);
+        }
+
+        [Fact]
+        public void AreaTimesLuminanceEqualsLuminousIntensity()
+        {
+            LuminousIntensity luminousIntensity = Area.FromSquareMeters(5) * Luminance.FromCandelasPerSquareMeter(10);
+            Assert.Equal(LuminousIntensity.FromCandela(50), luminousIntensity);
+        }
+
+        [Fact]
+        public void AreaTimesSpecificWeightEqualsForcePerLength()
+        {
+            ForcePerLength forcePerLength = Area.FromSquareMeters(20) * SpecificWeight.FromNewtonsPerCubicMeter(2000);
+            Assert.Equal(ForcePerLength.FromNewtonsPerMeter(40000), forcePerLength);
+        }
+
+        [Fact]
+        public void AreaTimesReciprocalLengthEqualsLength()
+        {
+            Length length = Area.FromSquareMeters(20) * ReciprocalLength.FromInverseMeters(5);
+            Assert.Equal(Length.FromMeters(100), length);
+        }
+
+        [Fact]
+        public void AreaTimesAreaDensityEqualsMass()
+        {
+            Mass mass = Area.FromSquareMeters(2) * AreaDensity.FromKilogramsPerSquareMeter(10);
+            Assert.Equal(Mass.FromKilograms(20), mass);
+        }
+
+        [Fact]
+        public void AreaTimesHeatFluxEqualsPower()
+        {
+            Power power = Area.FromSquareMeters(2) * HeatFlux.FromWattsPerSquareMeter(10);
+            Assert.Equal(Power.FromWatts(20), power);
+        }
+
+        [Fact]
+        public void AreaTimesForcePerLengthEqualsEqualsTorque()
+        {
+            Torque torque = Area.FromSquareMeters(2) * ForcePerLength.FromNewtonsPerMeter(10);
+            Assert.Equal(Torque.FromNewtonMeters(20), torque);
+        }
+
+        [Fact]
+        public void AreaDividedByReciprocalLengthEqualsVolume()
+        {
+            Volume volume = Area.FromSquareMeters(20) / ReciprocalLength.FromInverseMeters(5);
+            Assert.Equal(Volume.FromCubicMeters(4), volume);
+        }
     }
 }

UnitsNet.Tests/CustomCode/CoefficientOfThermalExpansionTests.cs

@@ -44,21 +44,8 @@ public class CoefficientOfThermalExpansionTests : CoefficientOfThermalExpansionT
         [Fact]
         public void CoefficientOfThermalExpansionTimesTemperatureDelta()
         {
-            double temperatureDeltaDegC = 2.0;
-            double ctePerDegC = 0.001;
-            CoefficientOfThermalExpansion cte = CoefficientOfThermalExpansion.FromPerDegreeCelsius(ctePerDegC);
-            TemperatureDelta dT = TemperatureDelta.FromDegreesCelsius(temperatureDeltaDegC);
-            AssertEx.EqualTolerance(cte * dT, ctePerDegC * temperatureDeltaDegC, 1e-10);
-        }
-
-        [Fact]
-        public void TemperatureDeltaTimesCoefficientOfThermalExpansion()
-        {
-            double temperatureDeltaDegC = 2.0;
-            double ctePerDegC = 0.001;
-            CoefficientOfThermalExpansion cte = CoefficientOfThermalExpansion.FromPerDegreeCelsius(ctePerDegC);
-            TemperatureDelta dT = TemperatureDelta.FromDegreesCelsius(temperatureDeltaDegC);
-            AssertEx.EqualTolerance(dT * cte, temperatureDeltaDegC * ctePerDegC, 1e-10);
+            Ratio expansionRatio = CoefficientOfThermalExpansion.FromPerDegreeCelsius(2) * TemperatureDelta.FromDegreesCelsius(0.001);
+            Assert.Equal(Ratio.FromDecimalFractions(0.002), expansionRatio);
         }
     }
 }

UnitsNet.Tests/CustomCode/DensityTests.cs

@@ -162,5 +162,19 @@ public void DensityTimesAreaEqualsLinearDensity()
             LinearDensity linearDensity = Density.FromGramsPerCubicCentimeter(10) * Area.FromSquareCentimeters(2);
             Assert.Equal(20, linearDensity.GramsPerCentimeter);
         }
+
+        [Fact]
+        public static void DensityTimesVolumeConcentrationEqualsMassConcentration()
+        {
+            MassConcentration massConcentration = Density.FromKilogramsPerCubicMeter(20) * VolumeConcentration.FromPercent(50);
+            Assert.Equal(massConcentration, MassConcentration.FromKilogramsPerCubicMeter(10));
+        }
+
+        [Fact]
+        public static void InverseDensityEqualsSpecificVolume()
+        {
+            SpecificVolume specificVolume = Density.FromKilogramsPerCubicMeter(4).Inverse();
+            Assert.Equal(specificVolume, SpecificVolume.FromCubicMetersPerKilogram(0.25));
+        }
     }
 }

UnitsNet.Tests/CustomCode/EnergyTests.cs

@@ -1,4 +1,4 @@
-// Licensed under MIT No Attribution, see LICENSE file at the root.
+// 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;
@@ -191,5 +191,33 @@ public void EnergyDividedBySpecificEnergyEqualsMass()
             Mass m = Energy.FromJoules(24) / SpecificEnergy.FromJoulesPerKilogram(8);
             Assert.Equal(Mass.FromKilograms(3), m);
         }
+
+        [Fact]
+        public void EnergyDividedByMolarEnergyEqualsAmountOfSubstance()
+        {
+            AmountOfSubstance m = Energy.FromJoules(24) / MolarEnergy.FromJoulesPerMole(8);
+            Assert.Equal(AmountOfSubstance.FromMoles(3), m);
+        }
+
+        [Fact]
+        public void EnergyDividedByAmountOfSubstanceEqualsMolarEnergy()
+        {
+            MolarEnergy m = Energy.FromJoules(24) / AmountOfSubstance.FromMoles(8);
+            Assert.Equal(MolarEnergy.FromJoulesPerMole(3), m);
+        }
+
+        [Fact]
+        public void EnergyDividedByVolumeEqualsEnergyDensity()
+        {
+            EnergyDensity m = Energy.FromJoules(24) / Volume.FromCubicMeters(8);
+            Assert.Equal(EnergyDensity.FromJoulesPerCubicMeter(3), m);
+        }
+
+        [Fact]
+        public void EnergyDividedByEnergyDensityEqualsVolume()
+        {
+            Volume m = Energy.FromJoules(24) / EnergyDensity.FromJoulesPerCubicMeter(8);
+            Assert.Equal(Volume.FromCubicMeters(3), m);
+        }
     }
 }

UnitsNet.Tests/CustomCode/IlluminanceTests.cs

@@ -22,6 +22,7 @@
 
 
 using System;
+using Xunit;
 
 namespace UnitsNet.Tests.CustomCode
 {
@@ -35,5 +36,12 @@ public class IlluminanceTests : IlluminanceTestsBase
         protected override double KiloluxInOneLux => 1E-3;
 
         protected override double MegaluxInOneLux => 1E-6;
+
+        [Fact]
+        public void IlluminanceTimesAreaEqualsLuminousFlux()
+        {
+            LuminousFlux luminousFlux = Illuminance.FromLux(10) * Area.FromSquareMeters(5);
+            Assert.Equal(LuminousFlux.FromLumens(50), luminousFlux);
+        }
     }
 }

UnitsNet.Tests/CustomCode/LuminousFluxTests.cs

@@ -22,12 +22,35 @@
 
 
 using System;
+using Xunit;
 
 namespace UnitsNet.Tests.CustomCode
 {
     public class LuminousFluxTests : LuminousFluxTestsBase
     {
         protected override bool SupportsSIUnitSystem => false;
         protected override double LumensInOneLumen => 1;
+
+        [Fact]
+        public void LuminousFluxDividedByAreaEqualsIlluminance()
+        {
+            var luminousFlux = LuminousFlux.FromLumens(100);
+            var area = Area.FromSquareMeters(10);
+
+            var illuminance = luminousFlux / area;
+
+            Assert.Equal(Illuminance.FromLux(10), illuminance);
+        }
+
+        [Fact]
+        public void LuniousFluxDividedByIlluminanceEqualsArea()
+        {
+            var luminousFlux = LuminousFlux.FromLumens(100);
+            var illuminance = Illuminance.FromLux(10);
+
+            var area = luminousFlux / illuminance;
+
+            Assert.Equal(Area.FromSquareMeters(10), area);
+        }
     }
 }

UnitsNet.Tests/CustomCode/MassTests.cs

@@ -164,5 +164,69 @@ public void AmountOfSubstanceFromMassAndMolarMass(
 
             AssertEx.EqualTolerance(expectedAmountOfSubstanceValue, amountOfSubstance.As(expectedAmountOfSubstanceUnit), tolerence);
         }
+
+        [Theory]
+        [InlineData(10, MassUnit.Kilogram,
+            5, SpecificVolumeUnit.CubicMeterPerKilogram,
+            50, VolumeUnit.CubicMeter)]
+        public void Multiplying_Mass_By_SpecificVolume_ReturnsVolume(double massValue, MassUnit massUnit, double specificVolumeValue,
+            SpecificVolumeUnit specificVolumeUnit, double expectedVolumeValue, VolumeUnit expectedVolumeUnit)
+        {
+            var mass = new Mass(massValue, massUnit);
+            var specificVolume = new SpecificVolume(specificVolumeValue, specificVolumeUnit);
+            var expectedVolume = new Volume(expectedVolumeValue, expectedVolumeUnit);
+
+            Volume volume = mass * specificVolume;
+
+            Assert.Equal(expectedVolume, volume);
+        }
+
+        [Theory]
+        [InlineData(10, MassUnit.Kilogram,
+            5, MassFlowUnit.KilogramPerSecond,
+            2, DurationUnit.Second)]
+        public void Dividing_Mass_By_MassFlow_ReturnsDuration(double massValue, MassUnit massUnit, double massFlowValue,
+            MassFlowUnit massFlowUnit, double expectedDurationValue, DurationUnit expectedDurationUnit)
+        {
+            var mass = new Mass(massValue, massUnit);
+            var massFlow = new MassFlow(massFlowValue, massFlowUnit);
+            var expectedDuration = new Duration(expectedDurationValue, expectedDurationUnit);
+
+            Duration duration = mass / massFlow;
+
+            Assert.Equal(expectedDuration, duration);
+        }
+
+        [Theory]
+        [InlineData(10, MassUnit.Kilogram,
+            5, AmountOfSubstanceUnit.Mole,
+            2, MolarMassUnit.KilogramPerMole)]
+        public void Dividing_Mass_By_AmountOfSubstance_ReturnsMolarMass(double massValue, MassUnit massUnit, double amountOfSubstanceValue,
+            AmountOfSubstanceUnit amountOfSubstanceUnit, double expectedMolarMassValue, MolarMassUnit expectedMolarMassUnit)
+        {
+            var mass = new Mass(massValue, massUnit);
+            var amountOfSubstance = new AmountOfSubstance(amountOfSubstanceValue, amountOfSubstanceUnit);
+            var expectedMolarMass = new MolarMass(expectedMolarMassValue, expectedMolarMassUnit);
+
+            MolarMass molarMass = mass / amountOfSubstance;
+
+            Assert.Equal(expectedMolarMass, molarMass);
+        }
+
+        [Theory]
+        [InlineData(10, MassUnit.Kilogram,
+            5, DensityUnit.KilogramPerCubicMeter,
+            2, VolumeUnit.CubicMeter)]
+        public void Dividing_Mass_By_Density_ReturnsVolume(double massValue, MassUnit massUnit, double densityValue,
+            DensityUnit densityUnit, double expectedVolumeValue, VolumeUnit expectedVolumeUnit)
+        {
+            var mass = new Mass(massValue, massUnit);
+            var density = new Density(densityValue, densityUnit);
+            var expectedVolume = new Volume(expectedVolumeValue, expectedVolumeUnit);
+
+            Volume volume = mass / density;
+
+            Assert.Equal(expectedVolume, volume);
+        }
     }
 }