Azure DevOps YAML pipeline - git diff not working correctly

Question

I am executing a git command in my Azure DevOps YAML pipeline to get changes between two commits like git diff commit1 commit2 --name-only via a PowerShell script - see full code below:

Write-Information "git diff --name-only $git_event_before $git_event_after --diff-filter=ACM ""*.txt"""
$txt_files = @($(git diff --name-only $git_event_before $git_event_after --diff-filter=ACM "*.txt"))
$txt_files = $txt_files | ForEach-Object { Join-Path $root_path $_ | Get-Item }

if ($txt_files.Count -eq 0) {
    Write-Error "Something went wrong, could not find any changed .txt files using the above 'git diff'"
}

This throws an error claiming no files were found. However, if I execute the very same git diff command locally where I do also have the repository synced, it returns the changed files as expected.

Do I need to manually update the repository that is already downloaded by the checkout-step of the pipeline ?

Answer 1

Could you try to run "git diff" this way

$gitDiffCmd = 'diff "origin/{0}" "origin/{0}@{{1}}" --name-only' -f $buildSourceBranch
$gitCommitFiles = Invoke-Git $gitDiffCmd

function Invoke-Git {
    [CmdletBinding()]
    [OutputType([string])]
    param (
        [Parameter(Mandatory)]
        [string] $Command 
    )
    try {
        $old_env = $env:GIT_REDIRECT_STDERR
        $env:GIT_REDIRECT_STDERR = '2>&1'
        $response = Invoke-Expression "git $Command "
        return $response
    } catch {
        Write-Host $_.ScriptStackTrace
    } finally {
        $env:GIT_REDIRECT_STDERR = $old_env
    }
}