Add test GetDefaultAbbreviationFallsBackToDefaultStringIfNotSpecified

Author: angularsen

Tests/UnitSystemTests.cs

@@ -183,6 +183,18 @@ public void AllUnitsImplementToStringForRussian()
             }
         }
 
+        [Test]
+        public void GetDefaultAbbreviationFallsBackToDefaultStringIfNotSpecified()
+        {
+            UnitSystem usUnits = UnitSystem.GetCached(CultureInfo.GetCultureInfo("en-US"));
+
+            // Act
+            string abbreviation = usUnits.GetDefaultAbbreviation(CustomUnit.Unit1);
+
+            // Assert
+            Assert.AreEqual("(no abbreviation for CustomUnit.Unit1)", abbreviation);
+        }
+
         [Test]
         public void GetDefaultAbbreviationFallsBackToUsEnglishCulture()
         {
@@ -202,6 +214,7 @@ public void GetDefaultAbbreviationFallsBackToUsEnglishCulture()
             Assert.AreEqual("US english abbreviation for Unit1", abbreviation);
         }
 
+
         [Test]
         public void ToStringRoundsToTwoDecimals()
         {