Address feet/inches parser review feedback

Author: angularsen

UnitsNet.Tests/CustomCode/LengthTests.FeetInches.cs

@@ -49,6 +49,7 @@ public static IEnumerable<object[]> ValidData
             ["1′1″", 1.08333333, EnglishUs], // Without space
             ["1 ft 1 in", 1.08333333, EnglishUs],
             ["1ft 1in", 1.08333333, EnglishUs],
+            ["1 FT 6 IN", 1.5, EnglishUs], // Unit parsing is case-insensitive
             ["-1'", -1, EnglishUs], // Feet only
             ["-1′", -1, EnglishUs], // Feet only
             ["-1,000′", -1000, EnglishUs], // Feet only, with separator
@@ -85,6 +86,7 @@ public void TryParseFeetInches(string str, double expectedFeet, string cultureNa
     [InlineData("1'000' 6\"", 1000.5)]
     [InlineData("1'000'6\"", 1000.5)]
     [InlineData("1'000'000' 2\"", 1000000.16666667)]
+    [InlineData("1' 1'000\"", 84.33333333)]
     [InlineData("-1'000' 6\"", -1000.5)]
     public void TryParseFeetInches_WhenGroupSeparatorIsFootAbbreviation_ParsesFeetAndInches(string str, double expectedFeet)
     {

UnitsNet/CustomCode/Quantities/Length.extra.cs

@@ -94,6 +94,8 @@ private static bool TryParseFeetInchesCombination(string str, IFormatProvider? f
             if (isNegative)
                 str = str.Substring(1).TrimStart();
 
+            // Prefer the rightmost foot abbreviation so "1'000' 6\"" treats grouping apostrophes as part of
+            // the feet value, then keep walking left if that split does not leave valid feet and inches parts.
             IReadOnlyList<string> footAbbreviations = UnitAbbreviationsCache.Default.GetUnitAbbreviations(LengthUnit.Foot, formatProvider);
             foreach (int splitEndIndex in GetPossibleUnitSplitEndIndexes(str, footAbbreviations))
             {