fix(filter)!: keep a comma inside a quoted list item

QueryKit.IntegrationTests/Tests/FilterParsingRegressionTests.cs

@@ -82,7 +82,7 @@ public async Task decimal_value_uses_invariant_culture()
     }
 
     [Fact]
-    public async Task list_value_with_comma_is_split_into_items()
+    public async Task list_value_with_comma_is_one_item()
     {
         // Arrange
         var testingServiceScope = new TestingServiceScope();
@@ -106,8 +106,8 @@ public async Task list_value_with_comma_is_split_into_items()
         var notInPeople = await queryablePeople.ApplyQueryKitFilter(notInInput).ToListAsync();
 
         // Assert
-        inPeople.Select(x => x.Id).Should().Equal(fakePersonTwo.Id);
-        notInPeople.Select(x => x.Id).Should().Equal(fakePersonOne.Id);
+        inPeople.Select(x => x.Id).Should().Equal(fakePersonOne.Id);
+        notInPeople.Select(x => x.Id).Should().Equal(fakePersonTwo.Id);
     }
 
     [Theory]

QueryKit.UnitTests/FilterParsingRegressionTests.cs

@@ -95,12 +95,12 @@ public void decimal_value_uses_invariant_culture_in_memory()
     }
 
     [Theory]
-    [InlineData("Title ^^ [\"Warm, with syrup\", \"a\\b\"]", new[] { "Warm", "with syrup", "a\\b" })]
-    [InlineData("Title !^^ [\"Warm, with syrup\", \"a\\b\"]", new[] { "Warm, with syrup" })]
-    [InlineData("Title ^^* [\"WARM, WITH SYRUP\"]", new[] { "Warm", "with syrup" })]
-    [InlineData("Title ^^ [\"\"\"Warm, with syrup\"\"\", \"Warm\"]", new[] { "Warm", "with syrup" })]
+    [InlineData("Title ^^ [\"Warm, with syrup\", \"a\\b\"]", new[] { "Warm, with syrup", "a\\b" })]
+    [InlineData("Title !^^ [\"Warm, with syrup\", \"a\\b\"]", new[] { "Warm", "with syrup" })]
+    [InlineData("Title ^^* [\"WARM, WITH SYRUP\"]", new[] { "Warm, with syrup" })]
+    [InlineData("Title ^^ [\"\"\"Warm, with syrup\"\"\", \"Warm\"]", new[] { "Warm, with syrup", "Warm" })]
     [InlineData("Title ^^ [\" Warm \", \"with syrup \"]", new[] { "Warm", "with syrup" })]
-    public void list_value_with_comma_is_split_into_items(string input, string[] expectedTitles)
+    public void list_value_with_comma_is_one_item(string input, string[] expectedTitles)
     {
         var people = new[]
         {

QueryKit/FilterParser.cs

@@ -3,6 +3,7 @@
 using System.Globalization;
 using System.Linq.Expressions;
 using System.Reflection;
+using System.Text;
 using Configuration;
 using Exceptions;
 using Operators;
@@ -353,9 +354,39 @@ from closingQuotes in Parse.Char('"').Repeat(count).Text()
         from openingBracket in Parse.Char('[')
         from content in SquareBracketValuesParser
         from closingBracket in Parse.Char(']')
-        select new RightSideValue("[" + string.Join(",", content.Select(x => x.Value)) + "]", false,
+        select new RightSideValue("[" + string.Join(",", content.Select(x => EscapeListItem(x.Value))) + "]", false,
             content.Any(x => x.IsDotOnlyNumber) ? "" : null);
 
+    // List items are joined with ',' so quoted items that contain ',' or '\' are escaped and split back with SplitListItems, which trims each item
+    private static string EscapeListItem(string item)
+        => item.Replace(@"\", @"\\").Replace(",", @"\,");
+
+    private static List<string> SplitListItems(string list)
+    {
+        var items = new List<string>();
+        var current = new StringBuilder();
+        var content = list.Substring(1, list.Length - 2);
+        for (var i = 0; i < content.Length; i++)
+        {
+            if (content[i] == '\\' && i + 1 < content.Length)
+            {
+                current.Append(content[++i]);
+            }
+            else if (content[i] == ',')
+            {
+                items.Add(current.ToString().Trim());
+                current.Clear();
+            }
+            else
+            {
+                current.Append(content[i]);
+            }
+        }
+        items.Add(current.ToString().Trim());
+
+        return items;
+    }
+
     private static readonly Parser<RightSideValue> RightSideValueChoiceParser =
         Parse.String("null").Text().Select(v => new RightSideValue(v, false))
             .Or(GuidFormatParser.Select(v => new RightSideValue(v, false)))
@@ -612,7 +643,7 @@ private static Expression CreateRightExprFromType(Type leftExprType, string righ
                 {
                     targetType = typeof(string);
                 }
-                var values = right.Trim('[', ']').Split(',').Select(x => x.Trim()).ToList();
+                var values = SplitListItems(right);
                 var elementType = targetType.IsArray ? targetType.GetElementType()! : targetType;
 
                 var expressions = values.Select(x =>
@@ -724,7 +755,7 @@ private static Expression CreateRightExprFromType(Type leftExprType, string righ
 
             if (right.StartsWith("[") && right.EndsWith("]"))
             {
-                var values = right.Trim('[', ']').Split(',').Select(x => x.Trim()).ToList();
+                var values = SplitListItems(right);
                 var elementType = targetType.IsArray ? targetType.GetElementType() : targetType;
 
                 var expressions = values.Select<string, Expression>(x =>

README.md

@@ -120,6 +120,8 @@ Here's an example for the `in` operator:
 var input = """(Age ^^ [20, 30, 40]) && (BirthMonth ^^* ["January", "February", "March"]) || (Id ^^ ["6d623e92-d2cf-4496-a2df-f49fa77328ee"])""";
 ```
 
+A quoted list item can hold a comma. For example, `Title ^^ ["Warm, with syrup", "Cold"]` has two items: `Warm, with syrup` and `Cold`.
+
 ### Property List Grouping
 
 Property list grouping allows you to apply a single comparison operation across multiple properties, making it easy to search for a value in any of several fields without writing repetitive conditions.