#258 Adds extension method for splitting with spans. Updates usages and unit tests to use extension method.

Author: crfloyd

src/JsonApiDotNetCore/Builders/LinkBuilder.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Text;
+using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Services;
 using Microsoft.AspNetCore.Http;
@@ -27,7 +28,7 @@ private static string GetNamespaceFromPath(string path, string entityName)
         {
             var sb = new StringBuilder();
             var entityNameSpan = entityName.AsSpan();
-            var subSpans = new SpanSplitter(ref path, '/');
+            var subSpans = path.SpanSplit('/');
             for (var i = 1; i < subSpans.Count; i++)
             {
                 var span = subSpans[i];

src/JsonApiDotNetCore/Extensions/StringExtensions.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using JsonApiDotNetCore.Internal;
 
 namespace JsonApiDotNetCore.Extensions
 {
@@ -62,6 +63,11 @@ public static IEnumerable<int> IndexesOf(this string str, char delimeter)
             }
             return indexes;
         }
+
+        public static SpanSplitter SpanSplit(this string str, char delimeter)
+        {
+            return SpanSplitter.Split(str, delimeter);
+        }
 
     }
 }

src/JsonApiDotNetCore/Internal/Query/RelatedAttrFilterQuery.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Services;
 
@@ -15,7 +16,7 @@ public RelatedAttrFilterQuery(
         {
             _jsonApiContext = jsonApiCopntext;
             var filterQueryAttribute = filterQuery.Attribute;
-            var filterQuerySubSpans = new SpanSplitter(ref filterQueryAttribute, '.');
+            var filterQuerySubSpans = filterQueryAttribute.SpanSplit('.');
             var subSpan1 = filterQuerySubSpans[0].ToString();
             var subSpan2 = filterQuerySubSpans[1].ToString();
             var relationship = GetRelationship(subSpan1);

src/JsonApiDotNetCore/Internal/SpanSplitter.cs

@@ -15,14 +15,19 @@ public readonly ref struct SpanSplitter
         public int Count => _substringIndexes.Count();
         public ReadOnlySpan<char> this[int index] => GetSpanForSubstring(index + 1);
 
-        public SpanSplitter(ref string str, char delimeter)
+        private SpanSplitter(ref string str, char delimeter)
         {
             _span = str.AsSpan();
             _delimeterIndexes = str.IndexesOf(delimeter).ToList();
             _substringIndexes = new List<Tuple<int, int>>();
             BuildSubstringIndexes();
         }
 
+        public static SpanSplitter Split(string str, char delimeter)
+        {
+            return new SpanSplitter(ref str, delimeter);
+        }
+
         [EditorBrowsable(EditorBrowsableState.Never)]
         public override bool Equals(object obj) => throw new NotSupportedException();
 

src/JsonApiDotNetCore/Middleware/RequestMiddleware.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Threading.Tasks;
+using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Primitives;
@@ -56,7 +57,7 @@ private static bool IsValidAcceptHeader(HttpContext context)
         private static bool ContainsMediaTypeParameters(string mediaType)
         {
             const char delimeter = ';';
-            var subSpans = new SpanSplitter(ref mediaType, delimeter);
+            var subSpans = mediaType.SpanSplit(delimeter);
             if (subSpans.Count == 0) return false;
             return subSpans.Count == 2 && subSpans[0].ToString() == Constants.ContentType;
         }

src/JsonApiDotNetCore/Services/JsonApiContext.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 using JsonApiDotNetCore.Builders;
 using JsonApiDotNetCore.Configuration;
+using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Internal.Generics;
 using JsonApiDotNetCore.Internal.Query;
@@ -76,7 +77,7 @@ public IJsonApiContext ApplyContext<T>(object controller)
             BasePath = linkBuilder.GetBasePath(context, _controllerContext.RequestEntity.EntityName);
             PageManager = GetPageManager();
 
-            var pathSpans = new SpanSplitter(ref requestPath, '/');
+            var pathSpans = requestPath.SpanSplit('/');
             IsRelationshipPath = pathSpans[pathSpans.Count - 2].ToString() == "relationships";
 
             return this;

src/JsonApiDotNetCore/Services/QueryParser.cs

@@ -99,7 +99,7 @@ protected virtual List<FilterQuery> ParseFilterQuery(string key, string value)
             var propertyNameSlice = key.AsSpan().Slice(openBracketIndex + 1, closedBracketIndex - openBracketIndex - 1);
             var propertyName = propertyNameSlice.ToString();
 
-            var spanSplitter = new SpanSplitter(ref value, COMMA);
+            var spanSplitter = value.SpanSplit(COMMA);
             for (var i = 0; i < spanSplitter.Count; i++)
             {
                 queries.Add(BuildFilterQuery(spanSplitter[i], propertyName));

test/UnitTests/Internal/SpanSplitterTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using Xunit;
 
@@ -88,7 +89,7 @@ protected void GivenStringWithCommaDelimeterAtBeginning()
         protected void WhenSplittingIntoSubstrings()
         {
             SpanSplitter spanSplitter;
-            spanSplitter = new SpanSplitter(ref _baseString, _delimeter);
+            spanSplitter = _baseString.SpanSplit(_delimeter);
             for (var i = 0; i < spanSplitter.Count; i++)
             {
                 var span = spanSplitter[i];