Public/Test-Condition.ps1
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function Test-Condition { <# .SYNOPSIS Evaluate whether a feature flag rule applies. .DESCRIPTION Takes the given context, properties, and rule/condition and evaluates whether the rule applies and what it's effect is. .PARAMETER Context The device context. .PARAMETER Properties The properties that matches given context. .PARAMETER Condition A condition to test which are part of rules. .EXAMPLE $context = Get-DeviceContext $properties = Read-PropertySet $rule = $rules[0] Test-Condition -Context $context -Properties $properties -Condition $rule This would return a true/false #> param ( [Parameter(Mandatory)] [hashtable] $Context, [Parameter(Mandatory)] [PropertySet] [PropertySetTransformAttribute()] $Properties, [Parameter(Mandatory)] [Hashtable] $Condition ) #region Recurse on groups if ($Condition.ContainsKey('AllOf')) { foreach ($child in $Condition.AllOf) { if (-not (Test-Condition -Context $Context -Properties $Properties -Condition $child)) { return $false } } return $true } if ($Condition.ContainsKey('AnyOf')) { foreach ($child in $Condition.AnyOf) { if (Test-Condition -Context $Context -Properties $Properties -Condition $child) { return $true } } return $false } if ($Condition.ContainsKey('Not')) { foreach ($child in $Condition.Not) { if (Test-Condition -Context $Context -Properties $Properties -Condition $child) { return $false } } return $true } #endregion Recurse on groups # Flat condition $propName = $Condition.Property $operator = $Condition.Operator $expected = $Condition.Value if (-not $Context.ContainsKey($propName)) { throw "Context is missing required property '$propName'" } if (-not $Properties.ContainsKey($propName)) { throw "Property metadata for '$propName' is missing" } $meta = $Properties.GetProperty($propName) $propType = $meta.Type $validation = $meta.Validation $actual = Convert-ToTypedValue -Type $propType -Value $Context[$propName] $testTypedValueSplat = @{ PropertyDefinition = $meta Value = $actual } Test-TypedValue @testTypedValueSplat | Out-Null if ( $operator -in @("In", "NotIn") -and $expected -isnot [System.Collections.IEnumerable] ) { throw 'Condition is using In/NotIn but not passing a list' } if ( $operator -in @("In", "NotIn") -and $expected -is [System.Collections.IEnumerable] -and -not ($expected -is [string]) ) { $expectedCoerced = @() foreach ($val in $expected) { $expectedCoerced += Convert-ToTypedValue -Type $propType -Value $val } } else { $expectedCoerced = Convert-ToTypedValue -Type $propType -Value $expected } switch ($operator) { "Equals" { return $actual -eq $expectedCoerced } "NotEquals" { return $actual -ne $expectedCoerced } "GreaterThan" { return $actual -gt $expectedCoerced } "LessThan" { return $actual -lt $expectedCoerced } "In" { return $expectedCoerced -contains $actual } "NotIn" { return -not ($expectedCoerced -contains $actual) } default { throw "Unsupported operator: $operator" } } } |