Simplify equality logic

Since a national significant number must be unique within a numbering plan, we only need to check the country and NSN.
TrevorPilley · Nov 4, 2024 · d0ce84b · d0ce84b
1 parent a17dcec
commit d0ce84b
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Showing 9 changed files with 291 additions and 220 deletions.
diff --git a/src/PhoneNumbers/CountryInfo.cs b/src/PhoneNumbers/CountryInfo.cs
@@ -10,7 +10,7 @@ namespace PhoneNumbers;
 /// A class which contains country information related to phone numbers.
 /// </summary>
 [DebuggerDisplay("{" + nameof(GetDebuggerDisplay) + "(),nq}")]
-public sealed partial class CountryInfo
+public sealed partial class CountryInfo : IEquatable<CountryInfo>
 {
     internal const string Africa = "Africa";
     internal const string Asia = "Asia";
@@ -122,6 +122,21 @@ internal CountryInfo()
     s_emptyIntArray;
     #endif
 
+    /// <inheritdoc/>
+    public static bool operator !=(CountryInfo? countryInfo1, CountryInfo? countryInfo2) =>
+        !(countryInfo1 == countryInfo2);
+
+    /// <inheritdoc/>
+    public static bool operator ==(CountryInfo? countryInfo1, CountryInfo? countryInfo2)
+    {
+        if (countryInfo1 is null)
+        {
+            return countryInfo2 is null;
+        }
+
+        return countryInfo1.Equals(countryInfo2);
+    }
+
     internal static IEnumerable<CountryInfo> GetCountries() =>
         typeof(CountryInfo)
             .GetProperties(BindingFlags.Public | BindingFlags.Static)
@@ -141,6 +156,31 @@ internal static IEnumerable<CountryInfo> GetCountries(Func<CountryInfo, bool> pr
     internal static PhoneNumberFormatter GetFormatter(string format) =>
         s_formatters.SingleOrDefault(x => x.CanFormat(format)) ?? throw new FormatException($"{format} is not a supported format");
 
+    /// <inheritdoc/>
+    public override bool Equals(object? obj) =>
+        Equals(obj as CountryInfo);
+
+    /// <inheritdoc/>
+    public bool Equals(CountryInfo? other)
+    {
+        if (other is null)
+        {
+            return false;
+        }
+
+        if (ReferenceEquals(this, other))
+        {
+            return true;
+        }
+
+        return Iso3166Code.Equals(other.Iso3166Code, StringComparison.Ordinal);
+    }
+
+    /// <inheritdoc/>
+    [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    public override int GetHashCode() =>
+        HashCode.Combine(Iso3166Code);
+
     /// <summary>
     /// Gets a value indicating whether the specified value has the calling code for this country.
     /// </summary>

diff --git a/src/PhoneNumbers/GeographicPhoneNumber.cs b/src/PhoneNumbers/GeographicPhoneNumber.cs
@@ -66,17 +66,14 @@ public bool Equals(GeographicPhoneNumber? other)
             return true;
         }
 
-        return Hint.Equals(other.Hint) &&
-            Country.Equals(other.Country) &&
-            GeographicArea.Equals(other.GeographicArea, StringComparison.Ordinal) &&
-            Kind.Equals(other.Kind) &&
-            (!HasNationalDestinationCode && !other.HasNationalDestinationCode || NationalDestinationCode!.Equals(other.NationalDestinationCode, StringComparison.Ordinal)) &&
-            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal) &&
-            SubscriberNumber.Equals(other.SubscriberNumber, StringComparison.Ordinal);
+        // The National Significant Number (NSN) must be unique within a numbering plan so only
+        // where the countries match and the NSNs match they are the the same phone number.
+        return Country.Equals(other.Country) &&
+            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal);
     }
 
     /// <inheritdoc/>
     [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
     public override int GetHashCode() =>
-        HashCode.Combine(Hint, Country, GeographicArea, Kind, NationalSignificantNumber, NationalDestinationCode, SubscriberNumber);
+        HashCode.Combine(Country, NationalSignificantNumber);
 }
diff --git a/src/PhoneNumbers/MobilePhoneNumber.cs b/src/PhoneNumbers/MobilePhoneNumber.cs
@@ -64,16 +64,14 @@ public bool Equals(MobilePhoneNumber? other)
             return true;
         }
 
-        return Hint.Equals(other.Hint) &&
-            Country.Equals(other.Country) &&
-            Kind.Equals(other.Kind) &&
-            (!HasNationalDestinationCode && !other.HasNationalDestinationCode || NationalDestinationCode!.Equals(other.NationalDestinationCode, StringComparison.Ordinal)) &&
-            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal) &&
-            SubscriberNumber.Equals(other.SubscriberNumber, StringComparison.Ordinal);
+        // The National Significant Number (NSN) must be unique within a numbering plan so only
+        // where the countries match and the NSNs match they are the the same phone number.
+        return Country.Equals(other.Country) &&
+            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal);
     }
 
     /// <inheritdoc/>
     [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
     public override int GetHashCode() =>
-        HashCode.Combine(Hint, Country, Kind, NationalSignificantNumber, NationalDestinationCode, SubscriberNumber);
+        HashCode.Combine(Country, NationalSignificantNumber);
 }
diff --git a/src/PhoneNumbers/NonGeographicPhoneNumber.cs b/src/PhoneNumbers/NonGeographicPhoneNumber.cs
@@ -78,16 +78,14 @@ public bool Equals(NonGeographicPhoneNumber? other)
             return true;
         }
 
-        return Hint.Equals(other.Hint) &&
-            Country.Equals(other.Country) &&
-            Kind.Equals(other.Kind) &&
-            (!HasNationalDestinationCode && !other.HasNationalDestinationCode || NationalDestinationCode!.Equals(other.NationalDestinationCode, StringComparison.Ordinal)) &&
-            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal) &&
-            SubscriberNumber.Equals(other.SubscriberNumber, StringComparison.Ordinal);
+        // The National Significant Number (NSN) must be unique within a numbering plan so only
+        // where the countries match and the NSNs match they are the the same phone number.
+        return Country.Equals(other.Country) &&
+            NationalSignificantNumber.Equals(other.NationalSignificantNumber, StringComparison.Ordinal);
     }
 
     /// <inheritdoc/>
     [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
     public override int GetHashCode() =>
-        HashCode.Combine(Hint, Country, Kind, NationalSignificantNumber, NationalDestinationCode, SubscriberNumber);
+        HashCode.Combine(Country, NationalSignificantNumber);
 }
diff --git a/test/PhoneNumbers.Tests/CountryInfoTests.cs b/test/PhoneNumbers.Tests/CountryInfoTests.cs
@@ -28,6 +28,60 @@ public void GetFormatter_U_Returns_NationalUnformattedPhoneNumberFormatter() =>
     public void GetFormatter_Throws_For_Invalid_Format() =>
         Assert.Throws<FormatException>(() => CountryInfo.GetFormatter("X"));
 
+    [Fact]
+    public void Equality_Both_Null()
+    {
+        var countryInfo1 = default(CountryInfo);
+        var countryInfo2 = default(CountryInfo);
+
+        Assert.Equal(countryInfo1, countryInfo2);
+        Assert.True(countryInfo1 == countryInfo2);
+        Assert.True(countryInfo1 == (object)countryInfo2);
+        Assert.False(countryInfo1 != countryInfo2);
+        Assert.False(countryInfo1 != (object)countryInfo2);
+    }
+
+    [Fact]
+    public void Equality_Same_Instance()
+    {
+        var countryInfo1 = TestHelper.CreateCountryInfo();
+        var countryInfo2 = countryInfo1;
+
+        Assert.Equal(countryInfo1, countryInfo2);
+        Assert.True(countryInfo1.Equals(countryInfo2));
+        Assert.True(countryInfo1.Equals((object)countryInfo2));
+        Assert.True(countryInfo1 == countryInfo2);
+        Assert.True(countryInfo1 == (object)countryInfo2);
+        Assert.False(countryInfo1 != countryInfo2);
+        Assert.False(countryInfo1 != (object)countryInfo2);
+    }
+
+    [Fact]
+    public void Equality_Same_Iso3166Code()
+    {
+        var countryInfo1 = new CountryInfo
+        {
+            CallingCode = "-1",
+            Continent = "Pangea",
+            Iso3166Code = "YZ",
+            Name = "Nowhere",
+        };
+
+        var countryInfo2 = new CountryInfo
+        {
+            CallingCode = "-1",
+            Continent = "Pangea",
+            Iso3166Code = "YZ",
+            Name = "Nowhere",
+        };
+
+        Assert.Equal(countryInfo1, countryInfo2);
+        Assert.True(countryInfo1.Equals(countryInfo2));
+        Assert.True(countryInfo1.Equals((object)countryInfo2));
+        Assert.True(countryInfo1 == countryInfo2);
+        Assert.False(countryInfo1 != countryInfo2);
+    }
+
     [Theory]
     [InlineData(default(string))]
     [InlineData("")]
@@ -64,6 +118,47 @@ public void HasTrunkPrefix_False() =>
     public void HasTrunkPrefix_True() =>
         Assert.True(TestHelper.CreateCountryInfo(trunkPrefix: "0").HasTrunkPrefix);
 
+    [Fact]
+    public void Inequality()
+    {
+        var countryInfo1 = new CountryInfo
+        {
+            CallingCode = "-1",
+            Continent = "Pangea",
+            Iso3166Code = "YZ",
+            Name = "Nowhere",
+        };
+
+        var countryInfo2 = default(CountryInfo);
+
+        Assert.NotEqual(countryInfo1, countryInfo2);
+        Assert.NotEqual(countryInfo2, countryInfo1);
+        Assert.False(countryInfo1.Equals(countryInfo2));
+        Assert.False(countryInfo1.Equals((object)countryInfo2));
+        Assert.False(countryInfo1 == countryInfo2);
+        Assert.False(countryInfo2 == countryInfo1);
+        Assert.False(countryInfo1 == (object)countryInfo2);
+        Assert.False(countryInfo2 == (object)countryInfo1);
+        Assert.True(countryInfo1 != countryInfo2);
+        Assert.True(countryInfo2 != countryInfo1);
+        Assert.True(countryInfo1 != (object)countryInfo2);
+        Assert.True(countryInfo2 != (object)countryInfo1);
+
+        // change the ISO3166 code
+        var countryInfo3 = new CountryInfo
+        {
+            CallingCode = "-1",
+            Continent = "Pangea",
+            Iso3166Code = "YY",
+            Name = "Nowhere",
+        };
+
+        Assert.NotEqual(countryInfo1, countryInfo3);
+        Assert.False(countryInfo1.Equals(countryInfo3));
+        Assert.False(countryInfo1 == countryInfo3);
+        Assert.True(countryInfo1 != countryInfo3);
+    }
+
     [Theory]
     [InlineData(default(string))]
     [InlineData("")]