Setting up an Arrange, Act, Assert comment template in Visual Studio 2022
To add a simple code snippet that allows a set of arrange, act and assert comments to be inserted using the short code of aaa, firstly, create a simple XML file with the following contents and save it as ArrangeActAssert.snippet:
<?xml version="1.0" encoding="utf-8"?>
<CodeSnippets xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <CodeSnippet Format="1.0.0">
        <Header>
            <Title>Arrange Act Assert</Title>
            <Author>Neil Docherty</Author>
            <Description>Adds an arrange, act, assert to a test</Description>
            <HelpUrl />
            <Keywords />
            <SnippetTypes />
            <Shortcut>aaa</Shortcut>
        </Header>
        <Snippet>
            <Declarations />
            <References />
            <Code Kind="any" Language="CSharp"><![CDATA[// Arrange
$end$
// Act
// Assert]]></Code>
        </Snippet>
    </CodeSnippet>
</CodeSnippets>
Then, to import it into Visual Studio, perform the following steps:
- Go to the 
Toolsmenu - Select 
Code Snippets Manager - Choose the 
Importbutton and locate and select yourArrangeActAssert.snippetfile and click Open. 
Now, when editing some C# code, typing aaa and hitting tab twice will create a block of text similar to:
// Arrange
// Act
// Assert