RedundantSpreadElement

Diagnostic Rule Overview

Field	Value
ID	SHIMMER1020
Analyzer title	Inline spread element
Analyzer message	Inline spread element
Code fix title	Flatten spread element
Default severity	Warning
Minimum framework/language version	C# 12
Category	ShimmeringUsage
Link to code	RedundantSpreadElementAnalyzer.cs
Code fix exists?	Yes

Explicitly creating an array before spreading it in a collection expression is redundant and should be inlined.

Flagged code:

namespace Tests;
class Test
{
    int[] Array => [1, .. new[] { 2, 3 }, 4];
}

Fixed code:

namespace Tests;
class Test
{
    int[] Array => [1, 2, 3, 4];
}

While this is not a bug, this will slow down your code and increase memory usage.