Problem

Test-FileExists and Test-DirHasFiles in scripts/powershell/common.ps1 do two things on the Success stream — they write the report line and return a bool:

function Test-FileExists {
    param([string]$Path, [string]$Description)
    if (Test-Path -Path $Path -PathType Leaf) {
        Write-Output "  [OK] $Description"
        return $true
    } else {
        Write-Output "  [FAIL] $Description"
        return $false
    }
}

check-prerequisites.ps1 piped the whole call to | Out-Null to throw away the boolean — which threw away the report line too.

Reproduction on current main (81bf741)

powershell.exe -NoProfile -File .specify/scripts/powershell/check-prerequisites.ps1 -IncludeTasks, in a project with specs/001-f/plan.md and specs/001-f/contracts/:

FEATURE_DIR:...\specs\001-f
AVAILABLE_DOCS:
=== line count: 2 ===

AVAILABLE_DOCS: is emitted with nothing under it. The bash and Python twins list all five documents for the same inputs, so the PowerShell variant silently returns less information — and any agent parsing the doc list sees none.

Fix

Drop only the boolean:

Test-FileExists -Path $paths.RESEARCH -Description 'research.md' | Where-Object { $_ -isnot [bool] }

Measured after the fix, same project plus research.md:

FEATURE_DIR:...\specs\001-f
AVAILABLE_DOCS:
  [OK] research.md
  [FAIL] data-model.md
  [FAIL] contracts/
  [FAIL] quickstart.md
  [FAIL] tasks.md
=== line count: 7 ===

No breaking change. JSON mode does not go through this path and is untouched. The booleans were already being discarded and are still discarded; the only difference is that the lines the helpers were writing now actually reach stdout. Exit codes unchanged.

The file stays ASCII-only — verified 0 non-ASCII bytes after the edit.

Verification

• Fail-before / pass-after: the new test fails on unpatched source and passes with the fix. File: 1 failed → 12 passed, 8 skipped.
• This is the first PowerShell text-mode test in this file — every existing PS test uses -Json, which is why the gap was never caught. It is gated on the file's existing HAS_PWSH or _WINDOWS_POWERSHELL guard.
• Scoped regression: failure set identical to the clean-main baseline captured on 81bf741 (0 pre-existing in scope).
• uvx ruff@0.15.0 check src tests → clean

Note this test file is also touched by my open #3785 and #3890, so expect a trivial append conflict depending on merge order — happy to rebase.

Written with assistance from Claude Code. Bug found, reproduced, and verified by me on current main with real powershell.exe.