修正溢位問題

Author: orlys

src/TaiwanUtilities/RocDateTime/RocDateTime.cs

@@ -49,7 +49,7 @@ private DateTimeOffset GetRawValue()
     /// <summary>
     /// 民國年。此值範圍為 1 至 999，若要判斷是否為民國前需使用 <see cref="BeforeEra"/> 屬性判斷。
     /// </summary>
-    public int Year => YearConversion.EraToMinguo(GetRawValue().Year, BeforeEra);
+    public int Year => YearConversion.EraToMinguo(GetRawValue().Year);
     public int Month => GetRawValue().Month;
     public int Day => GetRawValue().Day;
     public int Hour => GetRawValue().Hour;
@@ -172,16 +172,18 @@ private static class YearConversion
 
         private const int EraYearOffset = 1911;
 
-        public static int EraToMinguo(int eraYear, bool beforeEra)
+        public static int EraToMinguo(int eraYear)
         {
-            return eraYear - EraYearOffset + (beforeEra ? 1 : 0);
+            var value = eraYear > EraYearOffset
+                ? eraYear - EraYearOffset
+                : 1 + EraYearOffset - eraYear;
+            return value;
         }
         public static int MinguoToEra(int minGuoYear)
         {
             // 民國前一年為 1911, 民國一(元)年為 1912
-            return minGuoYear + EraYearOffset + (minGuoYear < 0 ? 1 : 0); ;
-
-
+            var value = minGuoYear + EraYearOffset + (minGuoYear < 1 ? 1 : 0);
+            return value;
         }
 
 

src/TaiwanUtilities/TaiwanUtilities.csproj

@@ -27,9 +27,9 @@
     <!-- Pack Settings -->
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageReadmeFile>README.md</PackageReadmeFile>
-    <PackageTags>Taiwan,Utilities,Decimal,Chinese,Parser,Converter,InternationalNumericFormatter,RocDateTime</PackageTags>
-    <PackageVersion>1.0.1</PackageVersion>
-    <!--<PackageVersion>1.0.1-alpha.1</PackageVersion>-->
+    <PackageTags>Taiwan,Utilities,ChineseDecimal,ChineseNumeric,Numeric,Parser,Converter,InternationalNumericFormatter,RocDateTime</PackageTags>
+    <PackageVersion>1.0.2</PackageVersion>
+    <!--<PackageVersion>1.0.3-alpha.1</PackageVersion>-->
 
     <!-- Source Link Settings-->
     <PublishRepositoryUrl>true</PublishRepositoryUrl>

test/TaiwanUtilities.UnitTests/RocDateTime/RocDateTimeTest.cs

@@ -20,4 +20,63 @@ public static void 國定假日判斷()
     {
         Assert.True(RocDateTime.Parse("114/1/1").IsHoliday);
     }
+
+    [Fact]
+    public static void 年份轉換測試()
+    {
+        Assert.Equal(
+            expected: RocDateTime.Era.AddYears(-2),
+            actual: new RocDateTime(-2, 1, 1));
+
+        Assert.Equal(
+            expected: RocDateTime.Era.AddYears(-1),
+            actual: new RocDateTime(-1, 1, 1));
+
+        Assert.Equal(
+            expected: RocDateTime.Era,
+            actual: new RocDateTime(0, 1, 1));
+
+        Assert.Equal(
+            expected: RocDateTime.Era,
+            actual: new RocDateTime(1, 1, 1));
+
+        Assert.Equal(
+            expected: RocDateTime.Era.AddYears(+1),
+            actual: new RocDateTime(2, 1, 1));
+
+        Assert.Equal(
+            expected: RocDateTime.Era.AddYears(+2),
+            actual: new RocDateTime(3, 1, 1));
+
+
+        var _1913 = RocDateTime.Era.AddYears(+1);
+        Assert.Equal(
+            expected: _1913.Year,
+            actual: 2);
+        Assert.False(_1913.BeforeEra);
+
+        var _1912 = RocDateTime.Era.AddYears(+0);
+        Assert.Equal(
+            expected: _1912.Year,
+            actual: 1);
+        Assert.False(_1912.BeforeEra);
+
+        var _1911 = RocDateTime.Era.AddYears(-1);
+        Assert.Equal(
+            expected: _1911.Year,
+            actual: 1);
+        Assert.True(_1911.BeforeEra);
+
+        var _1910 = RocDateTime.Era.AddYears(-2);
+        Assert.Equal(
+            expected: _1910.Year,
+            actual: 2);
+        Assert.True(_1910.BeforeEra);
+
+        var _1909 = RocDateTime.Era.AddYears(-3);
+        Assert.Equal(
+            expected: _1909.Year,
+            actual: 3);
+        Assert.True(_1909.BeforeEra);
+    }
 }

test/TaiwanUtilities.UnitTests/TaiwanUtilities.UnitTests.csproj

@@ -2,7 +2,8 @@
 
   <PropertyGroup>
     <TargetFramework>net6</TargetFramework> 
-    <IsPackable>false</IsPackable> 
+    <IsPackable>false</IsPackable>
+    <OutputType>Library</OutputType>
   </PropertyGroup>