AvoidTrailingWhitespace

Severity Level: Information

Default state: Always enabled

Description

This rule detects lines that end with trailing whitespace characters. Lines shouldn't end with trailing whitespace characters. Trailing whitespace makes diffs harder to review and can introduce subtle problems when line continuation uses a backtick (`), because the backtick must be the last character on the line.

Keeping lines free of trailing whitespace improves readability and helps keep source control history clean.

To learn more, see about_Parsing.

Example

Noncompliant

# The next line ends with a trailing space after the backtick.
Get-Process `
| Where-Object { $_.CPU -gt 100 }

When you run this script, PowerShell throws a parser error because the trailing space prevents line continuation. For example:

PS C:\WINDOWS\system32> Get-Process `
| Where-Object { $_.CPU -gt 100 }
At line:2 char:1
+ | Where-Object { $_.CPU -gt 100 }
+ ~
An empty pipe element is not allowed.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : EmptyPipeElement

Compliant

Get-Process `
| Where-Object { $_.CPU -gt 100 }

Configure rule

This rule is always enabled and isn't configurable. Use one of the following methods to avoid using this rule:

• Create a custom rule configuration file to include only the rules you want or exclude the rules you don't want.
• Add the appropriate rule suppression attributes to your code to suppress the rule for specific code blocks. For more information, see the Suppressing rules section of Using PSScriptAnalyzer.