MissingRemoveEmptyEntries

Diagnostic Rule Overview

Field	Value
ID	SHIMMER1030
Analyzer title	Use StringSplitOptions.RemoveEmptyEntries
Analyzer message	Use the overload of String.Split with StringSplitOptions.RemoveEmptyEntries to remove empty entries
Code fix title	Optimize string.Split()
Default severity	Info
Minimum framework/language version	N/A
Category	ShimmeringUsage
Link to code	MissingRemoveEmptyEntriesAnalyzer.cs
Code fix exists?	Yes

Detailed Explanation

The StringSplitOptions.RemoveEmptyEntries parameter allows you to remove empty entries in a single String.Split() call and therefore is more efficient than chaining with a LINQ call or two to do the same thing.

Currently, the checked patterns in the .Where() call are:

x => x.Length > 0
x => x.Length != 0
x => x.Length >= 1
x => x != ""
x => x != string.Empty
x => !string.IsNullOrEmpty(x)
x => x.Any()
x => x is not ""

Note that this diagnostic is not triggered if StringSplitOptions is already used.

Examples

Flagged code:

using System;
using System.Linq;

namespace Tests;
class Test
{
    void Do(string input)
    {
        var x = input.Split(' ')
            .Where(x => x.Length > 0);
    }
}

Fixed code:

using System;
using System.Linq;

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

Justification of the Severity

The code fix improves performance while keeping the code readable, but the flagged code does not cause any bugs or errors.