bhylu.com

Advertisements

Git Stash

A stash can temporarily save tracked working changes and staged changes while you handle another task. Untracked files need an explicit inclusion option.

How it works

The desk note has a tracked draft and a new scratch file. stash push -u captures both, leaving a clean working tree. Applying the stash restores the content while keeping the stash entry; dropping it afterward is a separate deliberate action. This separation is easier to inspect than assuming pop always succeeds cleanly.

Run the disposable lab

Use Windows PowerShell 5.1 or later and Git 2.28 or later. The reviewed CLI is Git for Windows 2.53.0.windows.2. These are PowerShell examples, not Git Bash commands. Save the download as stash.ps1 in a separate empty learning folder and run it in a separate process: powershell -NoProfile -ExecutionPolicy Bypass -File .\stash.ps1. The execution-policy option applies to that process, not your machine policy.

The script creates bhylu-git-stash and refuses an existing folder. It supplies two fictional seed files and repository-local settings, then runs the lesson commands. The literal separator is quoted as '--' so PowerShell passes it through the guard. A guard function named git calls the real CLI and stops on unexpected failures; Expect-GitFailure checks deliberately refused operations. Child-process configuration isolates your personal Git settings. File transports are allowed only for owned local remotes; internet transports are disabled in this lab. No hosting account, Apache or MySQL service is required. There is no Git playground. Leave the generated folder for inspection; choose another empty parent to run again.

Download the complete stash.ps1 lab

Example

stash.ps1

# Bhylu Git lab: Stash
# Run in a separate PowerShell process, in an empty learning folder.
# Existing lab folders are refused; nothing is pushed to an internet host.
$ErrorActionPreference = 'Stop'
$script:GitExe = (Get-Command git -CommandType Application | Select-Object -First 1).Source
$script:LabRoot = Join-Path (Get-Location) 'bhylu-git-stash'
if (Test-Path -LiteralPath $script:LabRoot) { throw 'Lab folder already exists. Choose another empty parent folder.' }
New-Item -ItemType Directory -Path $script:LabRoot | Out-Null
$env:GIT_CONFIG_NOSYSTEM = '1'
$env:GIT_CONFIG_GLOBAL = Join-Path $script:LabRoot 'empty-global-config'
[IO.File]::WriteAllText($env:GIT_CONFIG_GLOBAL, '')
$env:GIT_TERMINAL_PROMPT = '0'
$env:GIT_EDITOR = 'true'
$env:GIT_SEQUENCE_EDITOR = 'true'
$env:GIT_AUTHOR_DATE = '2026-01-10T10:00:00+00:00'
$env:GIT_COMMITTER_DATE = $env:GIT_AUTHOR_DATE
function git {
    & $script:GitExe -c protocol.allow=never -c protocol.file.allow=always @args
    if ($LASTEXITCODE -ne 0) { throw "Git exited with code $LASTEXITCODE" }
}
function Expect-GitFailure {
    & $script:GitExe -c protocol.allow=never -c protocol.file.allow=always @args
    if ($LASTEXITCODE -eq 0) { throw 'Expected Git to refuse this operation' }
}
function Assert-Equal($Actual, $Expected) {
    if ((($Actual | Out-String).Trim()) -cne (($Expected | Out-String).Trim())) { throw "Expected [$Expected], got [$Actual]" }
}
function Write-LabFile([string]$Name, [string]$Text) {
    $target = [IO.Path]::GetFullPath((Join-Path (Get-Location) $Name))
    if (!$target.StartsWith($script:LabRoot + [IO.Path]::DirectorySeparatorChar, [StringComparison]::OrdinalIgnoreCase)) { throw 'Path outside lab' }
    [IO.Directory]::CreateDirectory([IO.Path]::GetDirectoryName($target)) | Out-Null
    [IO.File]::WriteAllText($target, ($Text.Replace('\n', "`n") + "`n"), (New-Object Text.UTF8Encoding($false)))
}
function New-LabRepo([string]$Name) {
    New-Item -ItemType Directory -Path $Name | Out-Null
    Push-Location $Name
    try {
        git init --initial-branch=main
        git config --local user.name 'Repair Lab'
        git config --local user.email 'repair@example.invalid'
        git config --local core.autocrlf false
        git config --local commit.gpgSign false
        git config --local tag.gpgSign false
        git config --local core.hooksPath (Join-Path $script:LabRoot 'empty-hooks')
        Write-LabFile 'notes.md' 'Inspect hinge'
        Write-LabFile 'tasks.txt' 'desk=open'
        git add '--' notes.md tasks.txt
        git commit -m 'Record initial repair plan'
    } finally { Pop-Location }
}
Push-Location $script:LabRoot
try {
    New-LabRepo 'desk'
    Set-Location desk
    Write-LabFile 'notes.md' 'Draft inspection'
    Write-LabFile 'scratch.txt' 'Temporary thought'
    git stash push -u -m 'Pause inspection draft'
    Assert-Equal (git status --porcelain=v1) @('')
    git stash apply
    Assert-Equal (Get-Content notes.md) @('Draft inspection')
    Assert-Equal (Get-Content scratch.txt) @('Temporary thought')
    git stash drop
    Assert-Equal (git stash list) @('')
    Write-Output 'Verified: stash'
} finally { Pop-Location }
Focus on the lesson commands

This excerpt omits the seed repository and guard helpers. Use the complete download to run it.

Lesson excerpt

Write-LabFile 'notes.md' 'Draft inspection'
Write-LabFile 'scratch.txt' 'Temporary thought'
git stash push -u -m 'Pause inspection draft'
Assert-Equal (git status --porcelain=v1) @('')
git stash apply
Assert-Equal (Get-Content notes.md) @('Draft inspection')
Assert-Equal (Get-Content scratch.txt) @('Temporary thought')
git stash drop
Assert-Equal (git stash list) @('')

Expected result

Both drafts return after apply. The stash list becomes empty only after the explicit drop.

The complete script ends with Verified: stash only after its checks pass. Object IDs, temporary paths and progress output can differ.

Applying onto different work can conflict, and restoring the staged state requires attention to --index. A stash is local convenience, not a durable shared backup or a substitute for a clear commit on a working branch.

Advertisements