git-tfs workflow

cmdlet.ps1

function Tfs-UpdateFeature {
    [CmdletBinding()]
    param ()
        
    DynamicParam {
        $RuntimeParameterDictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
        
        $FeatureParameter = New-DynamicParameter -ParameterName "Feature" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Position 0 -Aliases @("b","f") -Mandatory
        $BranchParameter = New-DynamicParameter -ParameterName "MainBranch" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Position 1
        
        $RuntimeParameterDictionary.Add("Feature", $FeatureParameter)
        $RuntimeParameterDictionary.Add("MainBranch", $BranchParameter)
        
        $RuntimeParameterDictionary
    }   
    
    begin {
        $Feature = $PsBoundParameters["Feature"]
        $MainBrach = $PsBoundParameters["MainBranch"]
        
        # set default value
        if (!$MainBrach) {
            $MainBrach = "master"
        }
    }
    
    process {
        $shouldStash = git status --porcelain
        
        if ($shouldStash) {
            git stash save -u
        }
        
        git checkout $MainBrach
        git tfs pull
        git checkout $Feature
        git rebase $MainBrach
        
        if ($shouldStash) {
            git stash pop
        }
    }
}

function Tfs-StartFeature {
    [CmdletBinding()]
    param (
        [parameter(Mandatory=$true)]
        [string] $Feature,
        
        [parameter(Mandatory=$false)]
        [string] $MainBranch = "master"
    )
    
    git checkout $MainBranch
    git tfs pull
    git checkout -b $Feature
}

function Tfs-CommitFeature {
    [CmdletBinding()]
    param ()
	DynamicParam {
        New-SingleDynamicParameter -ParameterName "Feature" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Aliases "b"
    }

    begin {
        $Feature = $PsBoundParameters["Feature"]
    }
    
    process {
    
        if ($Feature) {
            git checkout $Feature
        }

        git tfs checkintool
    }
}

function Tfs-RemoveFeature {
    [CmdletBinding()]
    param ()
        
    DynamicParam {
        $RuntimeParameterDictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
        
        $FeatureParameter = New-DynamicParameter -ParameterName "Feature" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Position 0 -Aliases @("b","f") -Mandatory
        $BranchParameter = New-DynamicParameter -ParameterName "MainBranch" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Position 1
        
        $RuntimeParameterDictionary.Add("Feature", $FeatureParameter)
        $RuntimeParameterDictionary.Add("MainBranch", $BranchParameter)
        
        $RuntimeParameterDictionary
    }   
    
    begin {
        $Feature = $PsBoundParameters["Feature"]
        $MainBrach = $PsBoundParameters["MainBranch"]
        
        # set default value
        if (!$MainBrach) {
            $MainBrach = "master"
        }
    }

    process {
        git checkout $MainBrach
        git branch -D $Feature
    }
}

function BranchExists {
    param (
        [parameter(Mandatory=$true)]
        [string] $branch)
    
    $branches = (git branch --list) | ForEach-Object { $_.Substring(2) }
    
    return $branches.Contains($branch)
}

function Tfs-ValidateBranch {
    [CmdletBinding()]
    param ()

    DynamicParam {
        # Set the dynamic parameters' name
        $ParameterName = 'Branch'
        
        # Create the dictionary 
        $RuntimeParameterDictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
        # Create the collection of attributes
        $AttributeCollection = New-Object System.Collections.ObjectModel.Collection[System.Attribute]
        
        # Create and set the parameters' attributes
        $ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
        $ParameterAttribute.Mandatory = $true
        $ParameterAttribute.Position = 1

        # Add the attributes to the attributes collection
        $AttributeCollection.Add($ParameterAttribute)
        
        $AliasAttribute = New-Object System.Management.Automation.AliasAttribute("b")
        $AttributeCollection.Add($AliasAttribute)

        # Generate and set the ValidateSet 
        $arrSet = (git branch --list) | ForEach-Object { $_.Substring(2) }
        $ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute($arrSet)

        # Add the ValidateSet to the attributes collection
        $AttributeCollection.Add($ValidateSetAttribute)

        # Create and return the dynamic parameter
        $RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
        $RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)
        return $RuntimeParameterDictionary		
    }
    
    begin {
        # Bind the parameter to a friendly variable
        $Branch = $PsBoundParameters[$ParameterName]
    }

    process {
        # Your code goes here
        Write-Host "yeah $Branch exists"
        }
}

function Tfs-Validate-Branch2 {
[CmdletBinding()]
    param ()
    DynamicParam {
        New-DynamicParameter -ParameterName "Branch" -AllowedValues {(git branch --list) | ForEach-Object { $_.Substring(2) }} -Aliases "b"
    }

    begin {
        $Branch = $PsBoundParameters["Branch"]
    }
    
    process {
    
        # Your code goes here
        Write-Host "yeah $Branch exists"
        }
}

function New-SingleDynamicParameter {

    param(
        [parameter(Mandatory=$true, Position=0)]
        [string] $ParameterName,
        
        [parameter(Mandatory=$true, Position=1)]
        [scriptblock] $AllowedValues,
        
        [parameter(Mandatory=$false, Position=2)]
        [string] $Position = 0,
     
        [parameter(Mandatory=$false, Position=3, ValueFromRemainingArguments=$true)]
        [string[]] $Aliases,
        
        [switch] $Mandatory
        )
    
        # Create the dictionary 
        $RuntimeParameterDictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
        # Create the collection of attributes
        $AttributeCollection = New-Object System.Collections.ObjectModel.Collection[System.Attribute]
        
        # Create and set the parameters' attributes
        $ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
        $ParameterAttribute.Mandatory = $Mandatory
        $ParameterAttribute.Position = $Position

        # Add the attributes to the attributes collection
        $AttributeCollection.Add($ParameterAttribute)
        
        if ($Aliases) {
            $AliasAttribute = New-Object System.Management.Automation.AliasAttribute($Aliases)
            $AttributeCollection.Add($AliasAttribute)
        }

        # Set the ValidateSet 
        $ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute(Invoke-Command $AllowedValues)

        # Add the ValidateSet to the attributes collection
        $AttributeCollection.Add($ValidateSetAttribute)

        # Create and return the dynamic parameter
        $RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
        $RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)

        $RuntimeParameterDictionary		
}

function New-DynamicParameter {

    param(
        [parameter(Mandatory=$true, Position=0)]
        [string] $ParameterName,
        
        [parameter(Mandatory=$true, Position=1)]
        [scriptblock] $AllowedValues,
        
        [parameter(Mandatory=$false, Position=2)]
        [string] $Position = 0,
     
        [parameter(Mandatory=$false, Position=3, ValueFromRemainingArguments=$true)]
        [string[]] $Aliases,
        
        [switch] $Mandatory
        )
    
        # Create the collection of attributes
        $AttributeCollection = New-Object System.Collections.ObjectModel.Collection[System.Attribute]
        
        # Create and set the parameters' attributes
        $ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
        $ParameterAttribute.Mandatory = $Mandatory
        $ParameterAttribute.Position = $Position

        # Add the attributes to the attributes collection
        $AttributeCollection.Add($ParameterAttribute)
        
        if ($Aliases) {
            $AliasAttribute = New-Object System.Management.Automation.AliasAttribute($Aliases)
            $AttributeCollection.Add($AliasAttribute)
        }

        # Set the ValidateSet 
        $ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute(Invoke-Command $AllowedValues)

        # Add the ValidateSet to the attributes collection
        $AttributeCollection.Add($ValidateSetAttribute)

        # Create and return the dynamic parameter
        $RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
        $RuntimeParameter
}

you need PowerShell 3.0 for the Dynamic Parameters to work (http://www.microsoft.com/en-us/download/details.aspx?id=40855)