powershell/PSAvoidGlobalVars

powershell/PSAvoidGlobalVars is a PSScriptAnalyzer diagnostic emitted by tally for PowerShell snippets embedded in Dockerfiles.

Property	Value
Severity	Warning
Category	PSScriptAnalyzer
Default	Disabled in tally
Auto-fix	No

tally disables this rule by default for Dockerfile RUN snippets because a RUN executes statements inline rather than defining cmdlets, parameters, or modules with external callers. Re-enable it with include = ["powershell/PSAvoidGlobalVars"] or by setting rules.powershell.PSAvoidGlobalVars.severity = "warning" in .tally.toml.

Description

A variable is a unit of memory in which values are stored. PowerShell controls access to variables, functions, aliases, and drives through a mechanism known as scoping. Variables and functions that are present when PowerShell starts have been created in the global scope. Globally scoped variables include:

Automatic variables
Preference variables
Variables, aliases, and functions that are in your PowerShell profiles

To understand more about scoping, see Get-Help about_Scopes.

How

Use other scope modifiers for variables.

Examples

Problematic code

$Global:var1 = $null
function Test-NotGlobal ($var)
{
    $a = $var + $var1
}

Correct code

$var1 = $null
function Test-NotGlobal ($var1, $var2)
{
    $a = $var1 + $var2
}

Source

This rule documentation is adapted from Microsoft’s PSScriptAnalyzer documentation for AvoidGlobalVars, licensed under CC BY 4.0.

powershell/PSAvoidGlobalFunctions

powershell/PSAvoidInvokingEmptyMembers

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​Description

​How

​Examples

​Problematic code

​Correct code

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Description

How

Examples

Problematic code

Correct code

Source