UseTrimEntries

Diagnostic Rule Overview

Field	Value
ID	SHIMMER1031
Analyzer title	Use StringSplitOptions.TrimEntries
Analyzer message	Use the overload of string.Split with StringSplitOptions.TrimEntries to trim entries
Code fix title	Use StringSplitOptions.TrimEntries
Default severity	Info
Minimum framework/language version	.NET 5.0
Category	ShimmeringUsage
Link to code	UseTrimEntriesAnalyzer.cs
Code fix exists?	Yes

Detailed Explanation

In .NET 5.0 and later, string.Split supports StringSplitOptions.TrimEntries which trims individual substrings as they are parsed, avoiding intermediate allocations. Calling string.Split() followed by Select(x => x.Trim()) (and optionally ToArray()) is less efficient and more verbose.

Examples

Flagged code:

using System;
using System.Linq;

namespace Tests;
class Test
{
    void Do(string input)
    {
        var x = input.Split(',').Select(x => x.Trim());
    }
}

Fixed code:

using System;
using System.Linq;

namespace Tests;
class Test
{
    void Do(string input)
    {
        var x = input.Split(',', StringSplitOptions.TrimEntries);
    }
}

Justification of the Severity

Using StringSplitOptions.TrimEntries avoids creating intermediate strings and allocations from the split operation before they are trimmed, leading to cleaner code and better performance. Because it is a recommendation and requires .NET 5.0+, the severity is set to Info.

Related Rules

• SHIMMER1030: Missing StringSplitOptions.RemoveEmptyEntries