patch-kilo-autoscroll.ps1

patch-kilo-autoscroll.ps1

<#
.SYNOPSIS
  Patch the installed Kilo Code VS Code extension to fix the chat auto-scroll
  "can't detach from the latest message" bug.

.DESCRIPTION
  Two minimal fixes are applied to the minified webview bundles:
    1. Wheel-up input now records an interaction timestamp so handleScroll's
       near-bottom re-attach cannot immediately undo the pause.
    2. The near-bottom re-attach branch no longer clears userScrolled while the
       user just scrolled up.

  Menu: apply patch, check status, restore backup, quit.
  Backups are written as <file>.bak next to each patched bundle.
  An extension update overwrites the bundles, so re-apply after updates.

.PARAMETER ExtDir
  Optional explicit path to the installed extension folder
  (the one containing dist\webview.js). If omitted, the newest
  kilocode.kilo-code-* under .vscode\extensions / .vscode-insiders\extensions
  is auto-detected.
#>
param(
  [string]$ExtDir,
  [ValidateSet('apply', 'status', 'restore')]
  [string]$Action
)

$ErrorActionPreference = 'Stop'

# --- patch definitions -------------------------------------------------------

$fixes = @(
  @{
    name     = 'wheel-up timestamp'
    orig     = 'i.deltaY>=0||e.onWheelUp()'
    patched  = 'i.deltaY>=0||(n=performance.now(),e.onWheelUp())'
  },
  @{
    name     = 'near-bottom re-attach guard'
    orig     = 'o.userScrolled&&s("userScrolled",!1);return'
    patched  = 'o.userScrolled&&!h.isRecent()&&s("userScrolled",!1);return'
  }
)

# --- helpers ----------------------------------------------------------------

function Find-ExtDir {
  if ($ExtDir) {
    if (Test-Path -LiteralPath (Join-Path $ExtDir 'dist\webview.js')) { return $ExtDir }
    throw "ExtDir '$ExtDir' does not contain dist\webview.js."
  }
  $roots = @(
    (Join-Path $env:USERPROFILE '.vscode\extensions'),
    (Join-Path $env:USERPROFILE '.vscode-insiders\extensions')
  )
  $found = @()
  foreach ($r in $roots) {
    if (Test-Path -LiteralPath $r) {
      $found += Get-ChildItem -LiteralPath $r -Directory -Filter 'kilocode.kilo-code-*' -ErrorAction SilentlyContinue
    }
  }
  if ($found.Count -eq 0) { throw 'No kilocode.kilo-code-* extension folder found.' }
  # newest version folder name wins
  return ($found | Sort-Object Name -Descending | Select-Object -First 1).FullName
}

function Get-Targets {
  param([string]$dir)
  $dist = Join-Path $dir 'dist'
  if (!(Test-Path -LiteralPath $dist)) { throw "No dist folder in '$dir'." }
  # patch wherever any patch marker (orig or patched) lives
  Get-ChildItem -LiteralPath $dist -Filter '*.js' -File | Where-Object {
    $c = [IO.File]::ReadAllText($_.FullName)
    ($fixes | ForEach-Object { $_.orig, $_.patched } | Where-Object { $c.Contains($_) }).Count -gt 0
  }
}

function Get-FileState {
  param([IO.FileInfo]$file)
  $c = [IO.File]::ReadAllText($file.FullName)
  $state = [ordered]@{ file = $file.Name; orig = 0; patched = 0 }
  foreach ($f in $fixes) {
    if ($c.Contains($f.orig)) { $state.orig++ }
    if ($c.Contains($f.patched)) { $state.patched++ }
  }
  if ($state.patched -gt 0 -and $state.orig -eq 0) { $state.status = 'patched' }
  elseif ($state.patched -gt 0) { $state.status = 'partial' }
  elseif ($state.orig -gt 0) { $state.status = 'original' }
  else { $state.status = 'n/a' }
  return [pscustomobject]$state
}

function Invoke-Apply {
  param([IO.FileInfo[]]$targets)
  $applied = 0
  foreach ($t in $targets) {
    $bak = "$($t.FullName).bak"
    if (!(Test-Path -LiteralPath $bak)) {
      Copy-Item -LiteralPath $t.FullName -Destination $bak
    }
    $c = [IO.File]::ReadAllText($t.FullName)
    $changed = $false
    foreach ($f in $fixes) {
      if ($c.Contains($f.patched)) { continue }      # already applied
      if (!$c.Contains($f.orig)) { continue }        # not present in this bundle
      $c = $c.Replace($f.orig, $f.patched)
      $changed = $true
      Write-Host "  [$($t.Name)] applied: $($f.name)"
    }
    if ($changed) {
      [IO.File]::WriteAllText($t.FullName, $c)
      $applied++
    } else {
      Write-Host "  [$($t.Name)] already patched or no pattern - skipped"
    }
  }
  if ($applied -gt 0) {
    Write-Host ''
    Write-Host 'Done. Reload the VS Code window for the change to take effect' -ForegroundColor Green
    Write-Host '(Developer: Reload Window, or close and reopen).'
  }
}

function Invoke-Restore {
  param([IO.FileInfo[]]$targets)
  $restored = 0
  foreach ($t in $targets) {
    $bak = "$($t.FullName).bak"
    if (Test-Path -LiteralPath $bak) {
      Copy-Item -LiteralPath $bak -Destination $t.FullName -Force
      Write-Host "  [$($t.Name)] restored from backup"
      $restored++
    } else {
      Write-Host "  [$($t.Name)] no backup found - skipped"
    }
  }
  if ($restored -gt 0) {
    Write-Host ''
    Write-Host 'Restored. Reload the VS Code window.' -ForegroundColor Green
  }
}

function Show-Status {
  param([IO.FileInfo[]]$targets)
  if ($targets.Count -eq 0) {
    Write-Host 'No patchable bundles found in this extension.' -ForegroundColor Yellow
    return
  }
  $rows = foreach ($t in $targets) {
    $s = Get-FileState -file $t
    $color = switch ($s.status) { 'patched' { 'Green' } 'original' { 'Yellow' } 'partial' { 'Red' } default { 'DarkGray' } }
    [pscustomobject]@{
      File    = $s.file
      Status  = $s.status
      Orig    = $s.orig
      Patched = $s.patched
    }
  }
  $rows | Format-Table -AutoSize
  $summary = ($rows | Group-Object Status | ForEach-Object { "$($_.Name):$($_.Count)" }) -join '  '
  Write-Host "Summary: $summary"
}

# --- main menu --------------------------------------------------------------

try {
  $dir = Find-ExtDir
  Write-Host "Extension: $dir" -ForegroundColor Cyan
  $targets = @(Get-Targets -dir $dir)
  if ($targets.Count -eq 0) {
    Write-Host 'No bundles containing the auto-scroll pattern were found.' -ForegroundColor Yellow
    Write-Host 'The installed version may already be fixed or use different code.'
    return
  }
  Write-Host "Patchable bundles: $($targets.Count)"
  Write-Host ''

  if ($Action) {
    switch ($Action) {
      'apply'   { Invoke-Apply -targets $targets }
      'status'  { Show-Status -targets $targets }
      'restore' { Invoke-Restore -targets $targets }
    }
    return
  }

  while ($true) {
    Write-Host '--- Kilo Code auto-scroll patch ---'
    Write-Host '  1) Apply patch'
    Write-Host '  2) Check status'
    Write-Host '  3) Restore from backup'
    Write-Host '  4) Quit'
    $choice = Read-Host 'Select [1-4]'
    switch ($choice) {
      '1' { Invoke-Apply -targets $targets }
      '2' { Show-Status -targets $targets }
      '3' { Invoke-Restore -targets $targets }
      '4' { break }
      default { Write-Host 'Invalid choice.' -ForegroundColor Yellow }
    }
    Write-Host ''
    if ($choice -eq '4') { break }
  }
}
catch {
  Write-Host "Error: $($_.Exception.Message)" -ForegroundColor Red
  exit 1
}