add ability to overwrite a currency with a combination of CultureInfo…

… and RegionInfo

src/NMoneys/CurrencyConfiguration.cs

@@ -1,3 +1,5 @@
+using System.Globalization;
+
 namespace NMoneys;
 
 /// <summary>
@@ -52,4 +54,41 @@ public record CurrencyConfiguration()
 	/// Override <see cref="Currency.Entity"/>.
 	/// </summary>
 	public ValueTuple<ushort?, string?> Reference { get; init; } = (null, null);
+
+	/// <summary>
+	/// Creates a <see cref="Currency"/> configuration override with the data of the provided <paramref name="culture"/>
+	/// and its corresponding <see cref="RegionInfo"/>.
+	/// </summary>
+	/// <param name="culture">Instance with the overriding information (<see cref="CultureInfo.NumberFormat"/> "currency" properties).</param>
+	/// <param name="isObsolete">Whether the corresponding override is considered obsolete (<c>false</c> by default).</param>
+	/// <returns>An instance with the overriding data.</returns>
+	public static CurrencyConfiguration From(CultureInfo culture, bool isObsolete = false) =>
+		From(culture, new RegionInfo(culture.Name), isObsolete);
+
+	/// <summary>
+	/// Creates a <see cref="Currency"/> configuration override with the data of the provided <paramref name="culture"/>
+	/// and <paramref name="region"/>.
+	/// </summary>
+	/// <param name="culture">Instance with the overriding information (<see cref="CultureInfo.NumberFormat"/> "currency" properties).</param>
+	/// <param name="region">Instance with the overriding information (currency English and native names).</param>
+	/// <param name="isObsolete">Whether the corresponding override is considered obsolete (<c>false</c> by default).</param>
+	/// <returns>An instance with the overriding data.</returns>
+	public static CurrencyConfiguration From(CultureInfo culture, RegionInfo region, bool isObsolete = false)
+	{
+		NumberFormatInfo nf = culture.NumberFormat;
+		CurrencyConfiguration configuration = new()
+		{
+			NativeName = region.CurrencyNativeName,
+			EnglishName = region.CurrencyEnglishName,
+			Symbol = nf.CurrencySymbol,
+			SignificantDecimalDigits = (byte)nf.CurrencyDecimalDigits,
+			DecimalSeparator = nf.CurrencyDecimalSeparator,
+			GroupSeparator = nf.CurrencyGroupSeparator,
+			GroupSizes = nf.CurrencyGroupSizes.Select(s => (byte)s).ToArray(),
+			PositivePattern = (byte)nf.CurrencyPositivePattern,
+			NegativePattern = (byte)nf.CurrencyNegativePattern,
+			IsObsolete = isObsolete
+		};
+		return configuration;
+	}
 }

tests/NMoneys.Tests/CurrencyTester.Configuration.cs

@@ -1,3 +1,5 @@
+using System.Globalization;
+
 namespace NMoneys.Tests;
 
 public partial class CurrencyTester
@@ -6,20 +8,47 @@ public partial class CurrencyTester
 	public void Configure_Single_OverridesInformationSubset()
 	{
 		string englishName = "override";
-		Currency.Configure(CurrencyIsoCode.XXX, new CurrencyConfiguration{ EnglishName = englishName});
+		Currency.Configure(CurrencyIsoCode.XXX, new CurrencyConfiguration { EnglishName = englishName });
 		Currency overriden = Currency.Get(CurrencyIsoCode.XXX);
 		Assert.That(overriden.EnglishName, Is.EqualTo(englishName).And.Not.EqualTo(overriden.NativeName));
 	}
 
+	[Test, Explicit]
+	public void Configure_SingleCulture_OverridesInformationSubset()
+	{
+		CultureInfo paraguaySpanish = CultureInfo.GetCultureInfo("es-PY");
+
+		Currency.Configure(CurrencyIsoCode.PYG, CurrencyConfiguration.From(paraguaySpanish));
+		Currency overriden = Currency.Get(CurrencyIsoCode.PYG);
+		Assert.That(overriden.Symbol, Is.EqualTo(paraguaySpanish.NumberFormat.CurrencySymbol).And
+			.Not.EqualTo(@"₲"));
+	}
+
+	[Test, Explicit]
+	public void Configure_CultureAndRegion_OverridesInformationSubset()
+	{
+		CultureInfo somali = CultureInfo.GetCultureInfo("so-SO");
+		RegionInfo djibuti = new("so-DJ");
+
+		Currency.Configure(CurrencyIsoCode.SOS, CurrencyConfiguration.From(somali, djibuti));
+		Currency overriden = Currency.Get(CurrencyIsoCode.SOS);
+		// according to .NET, there are no decimals in shillings, but according to ISO there actually are
+		// (although inflation turns them useless and are not in the denominations)
+		Assert.That(overriden.SignificantDecimalDigits, Is.EqualTo(0).And
+			.Not.EqualTo(2));
+		// even though somali is spoken in Djibuti, they do not have "shillings", but "francs"
+		Assert.That(overriden.EnglishName, Does.Contain("Franc").And
+			.Not.Contains("Shilling"));
+	}
+
 	[Test, Explicit]
 	public void Configure_Multiple_OverridesInformationSubset()
 	{
 		string englishName = "override";
-		Currency.Configure(new []
-		{
-			(CurrencyIsoCode.XXX, new CurrencyConfiguration{ EnglishName = englishName}),
-			(CurrencyIsoCode.XTS, new CurrencyConfiguration{ EnglishName = englishName})
-		});
+		Currency.Configure([
+			(CurrencyIsoCode.XXX, new CurrencyConfiguration { EnglishName = englishName }),
+			(CurrencyIsoCode.XTS, new CurrencyConfiguration { EnglishName = englishName })
+		]);
 		Currency xxx = Currency.Get(CurrencyIsoCode.XXX);
 		Assert.That(xxx.EnglishName, Is.EqualTo(englishName).And.Not.EqualTo(xxx.NativeName));
 		Currency xts = Currency.Get(CurrencyIsoCode.XTS);
@@ -31,7 +60,7 @@ public void Configure_AfterInitialization_Exception()
 	{
 		Currency xxx = Currency.Get(CurrencyIsoCode.XXX); // initializes the currency
 
-		Assert.That(()=>Currency.Configure(CurrencyIsoCode.XXX, new CurrencyConfiguration()),
+		Assert.That(() => Currency.Configure(CurrencyIsoCode.XXX, new CurrencyConfiguration()),
 			Throws.InstanceOf<InitializedCurrencyException>());
 	}
 }