unsloth/tests/test_studio_install_workspace_guard.py

"""install.sh/install.ps1 must refuse to rm -rf an existing Unsloth venv in env-mode without a sentinel."""

from __future__ import annotations

import re
import subprocess
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parents[1]
INSTALL_SH = REPO_ROOT / "install.sh"
INSTALL_PS1 = REPO_ROOT / "install.ps1"
SETUP_PS1 = REPO_ROOT / "studio" / "setup.ps1"
SETUP_SH = REPO_ROOT / "studio" / "setup.sh"

# Stubs for helpers the extracted guard block calls; mv-based replacement reproduces the venv-gone
# effect without the full rollback machinery.
_INSTALL_GUARD_STUBS = (
    'substep() { :; }\n_start_studio_venv_replacement() {\n    mv -- "$1" "$1.replaced"\n}\n'
)


def _extract_install_sh_guard_block() -> str:
    """Extract install.sh's venv guard block (up to the first elif) as a self-contained snippet."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    m = re.search(
        r'(if \[ -x "\$VENV_DIR/bin/python" \]; then\n.*?)elif \[ "\$_STUDIO_HOME_REDIRECT" != "env"',
        src,
        re.DOTALL,
    )
    assert m, "install.sh venv guard block not found"
    return m.group(1) + "fi\n"


def _build_install_guard_script(
    studio_home: Path,
    redirect: str,
    block: str | None = None,
) -> str:
    """Build a self-contained bash script exercising the extracted guard block (with helper stubs)."""
    if block is None:
        block = _extract_install_sh_guard_block()
    return (
        _INSTALL_GUARD_STUBS
        + f'STUDIO_HOME="{studio_home}"\n'
        + f'VENV_DIR="$STUDIO_HOME/unsloth_studio"\n'
        + f'_STUDIO_HOME_REDIRECT="{redirect}"\n'
        + block
        + "echo RESULT=ok\n"
    )


def _run_install_guard(
    studio_home: Path,
    redirect: str,
    create_share_conf: bool = False,
    create_bin_shim: bool = False,
    create_venv_marker: bool = False,
) -> subprocess.CompletedProcess:
    venv_dir = studio_home / "unsloth_studio"
    (venv_dir / "bin").mkdir(parents = True, exist_ok = True)
    py = venv_dir / "bin" / "python"
    py.write_text("#!/bin/sh\nexit 0\n")
    py.chmod(0o755)
    if create_share_conf:
        (studio_home / "share").mkdir(parents = True, exist_ok = True)
        (studio_home / "share" / "studio.conf").write_text("")
    if create_bin_shim:
        (studio_home / "bin").mkdir(parents = True, exist_ok = True)
        (studio_home / "bin" / "unsloth").write_text("")
    if create_venv_marker:
        (venv_dir / ".unsloth-studio-owned").write_text("")
    script = _build_install_guard_script(studio_home, redirect)
    return subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )


def test_env_mode_blocks_unsloth_studio_without_sentinels(tmp_path):
    studio_home = tmp_path / "ws"
    res = _run_install_guard(studio_home, redirect = "env")
    assert res.returncode != 0, (
        "env-mode without sentinels must refuse to rm -rf $VENV_DIR; "
        f"stdout={res.stdout!r} stderr={res.stderr!r}"
    )
    assert "does not look like an Unsloth Studio install" in res.stderr
    assert (studio_home / "unsloth_studio" / "bin" / "python").is_file()


def test_env_mode_passes_when_share_studio_conf_present(tmp_path):
    studio_home = tmp_path / "ws"
    res = _run_install_guard(studio_home, redirect = "env", create_share_conf = True)
    assert res.returncode == 0, (
        f"share/studio.conf sentinel must allow cleanup;"
        f" stdout={res.stdout!r} stderr={res.stderr!r}"
    )
    assert "RESULT=ok" in res.stdout
    assert not (studio_home / "unsloth_studio").exists()


def test_env_mode_passes_when_bin_unsloth_shim_present(tmp_path):
    studio_home = tmp_path / "ws"
    res = _run_install_guard(studio_home, redirect = "env", create_bin_shim = True)
    assert res.returncode == 0, res.stderr
    assert not (studio_home / "unsloth_studio").exists()


def test_default_mode_skips_sentinel_check(tmp_path):
    studio_home = tmp_path / "ws"
    res = _run_install_guard(studio_home, redirect = "default")
    assert res.returncode == 0, res.stderr
    assert "RESULT=ok" in res.stdout
    assert not (studio_home / "unsloth_studio").exists()


def test_install_ps1_has_matching_env_mode_guard():
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    block_start = src.index("if (Test-Path -LiteralPath $VenvPython)")
    block = src[block_start : block_start + 2000]
    assert (
        "$StudioRedirectMode -eq 'env'" in block
    ), "install.ps1 must gate Remove-Item $VenvDir on env-mode"
    assert "share\\studio.conf" in block, "install.ps1 guard must check share\\studio.conf sentinel"
    assert "bin\\unsloth.exe" in block, "install.ps1 guard must check bin\\unsloth.exe sentinel"
    assert "Refusing to delete non-Unsloth venv" in block


def test_setup_ps1_has_writability_probe():
    src = SETUP_PS1.read_text(encoding = "utf-8")
    idx = src.index("if (Test-Path -LiteralPath $_studioOverride -PathType Container)")
    block = src[idx : idx + 2000]
    assert (
        "WriteAllText" in block
    ), "setup.ps1 must write-probe UNSLOTH_STUDIO_HOME like setup.sh:417"
    assert (
        "is not writable" in block
    ), "setup.ps1 probe failure must produce a clear writable-error message"


def test_env_mode_blocks_when_bin_unsloth_is_a_directory(tmp_path):
    """A bare directory at bin/unsloth must NOT pass the sentinel (regression: `-e` accepted any type)."""
    studio_home = tmp_path / "ws"
    venv = studio_home / "unsloth_studio"
    (venv / "bin").mkdir(parents = True)
    py = venv / "bin" / "python"
    py.write_text("#!/bin/sh\nexit 0\n")
    py.chmod(0o755)
    (venv / "important.txt").write_text("keep me")
    (studio_home / "bin" / "unsloth").mkdir(parents = True)
    script = _build_install_guard_script(studio_home, "env")
    res = subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )
    assert res.returncode != 0, (
        "directory at bin/unsloth must NOT satisfy the Unsloth sentinel; "
        f"stdout={res.stdout!r} stderr={res.stderr!r}"
    )
    assert (venv / "important.txt").is_file(), "unrelated workspace data must survive"


def test_env_mode_passes_when_bin_unsloth_is_a_symlink(tmp_path):
    """A symlink at bin/unsloth (real installer artefact) must still satisfy the sentinel."""
    studio_home = tmp_path / "ws"
    venv = studio_home / "unsloth_studio"
    (venv / "bin").mkdir(parents = True)
    py = venv / "bin" / "python"
    py.write_text("#!/bin/sh\nexit 0\n")
    py.chmod(0o755)
    (studio_home / "bin").mkdir(parents = True)
    target = studio_home / "bin" / "unsloth-real"
    target.write_text("#!/bin/sh\nexit 0\n")
    target.chmod(0o755)
    (studio_home / "bin" / "unsloth").symlink_to(target)
    script = _build_install_guard_script(studio_home, "env")
    res = subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )
    assert res.returncode == 0, res.stderr
    assert "RESULT=ok" in res.stdout
    assert not venv.exists()


def test_install_ps1_sentinel_uses_pathtype_leaf():
    """Remove-Item $VenvDir gate must use -PathType Leaf so a sentinel-path directory cannot satisfy it."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    block_start = src.index("if (Test-Path -LiteralPath $VenvPython)")
    block = src[block_start : block_start + 2000]
    assert (
        'share\\studio.conf") -PathType Leaf' in block
    ), "install.ps1 share\\studio.conf check must use -PathType Leaf"
    assert (
        'bin\\unsloth.exe") -PathType Leaf' in block
    ), "install.ps1 bin\\unsloth.exe check must use -PathType Leaf"


def test_setup_ps1_stale_venv_has_env_mode_guard():
    """setup.ps1 stale-venv branch must gate Remove-Item $VenvDir on a custom-root Unsloth sentinel."""
    src = SETUP_PS1.read_text(encoding = "utf-8")
    idx = src.index("Stale venv detected")
    block = src[idx : idx + 1500]
    assert (
        "$StudioHomeIsCustom" in block
    ), "setup.ps1 stale-venv branch must gate on $StudioHomeIsCustom"
    assert (
        'share\\studio.conf") -PathType Leaf' in block
    ), "setup.ps1 stale-venv guard must check share\\studio.conf with -PathType Leaf"
    assert (
        'bin\\unsloth.exe") -PathType Leaf' in block
    ), "setup.ps1 stale-venv guard must check bin\\unsloth.exe with -PathType Leaf"
    # The guard must fire BEFORE the destructive call.
    guard_idx = block.index("$StudioHomeIsCustom")
    rm_idx = block.index("Remove-Item -LiteralPath $VenvDir")
    assert guard_idx < rm_idx, "custom-root guard must precede Remove-Item -LiteralPath $VenvDir"


def test_setup_sh_prebuilt_llama_cpp_has_ownership_guard():
    """setup.sh prebuilt llama.cpp path must _assert_studio_owned_or_absent before install_llama_prebuilt.py."""
    src = SETUP_SH.read_text(encoding = "utf-8")
    idx = src.index("installing prebuilt llama.cpp...")
    block = src[idx : idx + 2000]
    assert (
        '_assert_studio_owned_or_absent "$LLAMA_CPP_DIR" "llama.cpp install"' in block
    ), "setup.sh must guard the prebuilt llama.cpp path with the ownership marker"
    guard_idx = block.index('_assert_studio_owned_or_absent "$LLAMA_CPP_DIR"')
    # Anchor on the actual command-array entry, not the why-comment mention.
    helper_idx = block.index('python "$SCRIPT_DIR/install_llama_prebuilt.py"')
    assert guard_idx < helper_idx, "ownership guard must precede the install_llama_prebuilt.py call"


def test_setup_ps1_prebuilt_llama_cpp_has_ownership_guard():
    """setup.ps1 prebuilt llama.cpp path must Assert-StudioOwnedOrAbsent before install_llama_prebuilt.py."""
    src = SETUP_PS1.read_text(encoding = "utf-8")
    idx = src.index("installing prebuilt llama.cpp bundle (preferred path)")
    block = src[idx : idx + 2000]
    assert (
        'Assert-StudioOwnedOrAbsent -Path $LlamaCppDir -Label "llama.cpp install"' in block
    ), "setup.ps1 must guard the prebuilt llama.cpp path with Assert-StudioOwnedOrAbsent"
    guard_idx = block.index("Assert-StudioOwnedOrAbsent -Path $LlamaCppDir")
    # Anchor on the actual command-array entry, not the why-comment mention.
    helper_idx = block.index('"$PSScriptRoot\\install_llama_prebuilt.py"')
    assert (
        guard_idx < helper_idx
    ), "Assert-StudioOwnedOrAbsent must precede the install_llama_prebuilt.py call"


def test_setup_ps1_adopts_existing_whisper_prebuilt_marker():
    text = SETUP_PS1.read_text(encoding = "utf-8")
    helper_start = text.index("function Test-StudioOwnedAdoptable")
    helper_end = text.index("function Assert-StudioOwnedOrAbsent", helper_start)
    helper = text[helper_start:helper_end]
    assert "UNSLOTH_WHISPER_PREBUILT_INFO.json" in helper


def test_env_mode_passes_when_venv_marker_present(tmp_path):
    """install.sh env-mode guard must accept the in-VENV .unsloth-studio-owned marker as a sentinel."""
    studio_home = tmp_path / "ws"
    res = _run_install_guard(studio_home, redirect = "env", create_venv_marker = True)
    assert (
        res.returncode == 0
    ), f"in-VENV marker must allow cleanup; stdout={res.stdout!r} stderr={res.stderr!r}"
    assert "RESULT=ok" in res.stdout
    assert not (studio_home / "unsloth_studio").exists()


def test_env_mode_blocks_when_bin_unsloth_is_symlink_to_directory(tmp_path):
    """install.sh guard must reject a symlink-to-directory at bin/unsloth; only -f (file/symlink-to-file) counts."""
    studio_home = tmp_path / "ws"
    venv = studio_home / "unsloth_studio"
    (venv / "bin").mkdir(parents = True)
    py = venv / "bin" / "python"
    py.write_text("#!/bin/sh\nexit 0\n")
    py.chmod(0o755)
    (venv / "important.txt").write_text("keep me")
    (studio_home / "bin").mkdir(parents = True)
    target_dir = studio_home / "bin" / "unsloth-target-dir"
    target_dir.mkdir()
    (studio_home / "bin" / "unsloth").symlink_to(target_dir)
    script = _build_install_guard_script(studio_home, "env")
    res = subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )
    assert res.returncode != 0, (
        "symlink-to-directory at bin/unsloth must NOT pass; "
        f"stdout={res.stdout!r} stderr={res.stderr!r}"
    )
    assert (venv / "important.txt").is_file(), "unrelated workspace data must survive"


def test_env_mode_blocks_when_bin_unsloth_is_broken_symlink(tmp_path):
    """install.sh guard must reject a broken symlink at bin/unsloth."""
    studio_home = tmp_path / "ws"
    venv = studio_home / "unsloth_studio"
    (venv / "bin").mkdir(parents = True)
    py = venv / "bin" / "python"
    py.write_text("#!/bin/sh\nexit 0\n")
    py.chmod(0o755)
    (venv / "important.txt").write_text("keep me")
    (studio_home / "bin").mkdir(parents = True)
    (studio_home / "bin" / "unsloth").symlink_to(studio_home / "bin" / "does-not-exist")
    script = _build_install_guard_script(studio_home, "env")
    res = subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )
    assert (
        res.returncode != 0
    ), f"broken symlink at bin/unsloth must NOT pass; stdout={res.stdout!r} stderr={res.stderr!r}"
    assert (venv / "important.txt").is_file()


def test_install_sh_writes_venv_marker_after_uv_venv():
    """install.sh must write .unsloth-studio-owned into $VENV_DIR right after `uv venv` succeeds."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    create_idx = src.index('run_install_cmd "create venv" uv venv "$VENV_DIR"')
    tail = src[create_idx : create_idx + 600]
    assert (
        ".unsloth-studio-owned" in tail
    ), "install.sh must write .unsloth-studio-owned after uv venv create"


def test_install_ps1_writes_venv_marker_after_uv_venv():
    """install.ps1 must write .unsloth-studio-owned into $VenvDir after `uv venv` succeeds."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    venv_create = src.index("uv venv $VenvDir --python")
    tail = src[venv_create : venv_create + 1500]
    assert (
        ".unsloth-studio-owned" in tail
    ), "install.ps1 must write .unsloth-studio-owned after uv venv create"


def test_install_ps1_guard_accepts_venv_marker():
    """install.ps1 env-mode guard must accept the in-VENV .unsloth-studio-owned marker as a sentinel."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    block_start = src.index("if (Test-Path -LiteralPath $VenvPython)")
    block = src[block_start : block_start + 2000]
    assert (
        '$VenvDir ".unsloth-studio-owned") -PathType Leaf' in block
    ), "install.ps1 guard must check the in-VENV marker with -PathType Leaf"


def test_setup_helpers_gate_on_canonical_custom_root():
    """setup.sh/setup.ps1 ownership guards must gate on a canonical custom-vs-legacy root comparison."""
    sh_src = SETUP_SH.read_text(encoding = "utf-8")
    sh_idx = sh_src.index("_assert_studio_owned_or_absent() {")
    sh_func = sh_src[sh_idx : sh_idx + 600]
    assert (
        '"$_STUDIO_HOME_IS_CUSTOM" = true' in sh_func
    ), "setup.sh _assert_studio_owned_or_absent must gate on _STUDIO_HOME_IS_CUSTOM"
    assert (
        "_LEGACY_STUDIO_HOME=" in sh_src
        and "_studio_home_canon=" in sh_src
        and "_STUDIO_HOME_IS_CUSTOM=" in sh_src
    ), "setup.sh must compute the canonical custom-root flag"

    ps_src = SETUP_PS1.read_text(encoding = "utf-8")
    ps_idx = ps_src.index("function Assert-StudioOwnedOrAbsent")
    ps_func = ps_src[ps_idx : ps_idx + 800]
    assert (
        "$StudioHomeIsCustom -and" in ps_func
    ), "setup.ps1 Assert-StudioOwnedOrAbsent must gate on $StudioHomeIsCustom"
    assert (
        "$StudioOwnedMarker) -PathType Leaf" in ps_func
    ), "setup.ps1 marker check must use -PathType Leaf so a directory cannot satisfy it"


def test_setup_ps1_inplace_git_sync_marks_studio_owned():
    """setup.ps1 in-place git-sync branch must Mark-StudioOwned after a successful sync."""
    src = SETUP_PS1.read_text(encoding = "utf-8")
    inplace_idx = src.index('Test-Path -LiteralPath (Join-Path $LlamaCppDir ".git")')
    # The in-place branch ends just before the temp-dir clone branch.
    clone_idx = src.index("Cloning llama.cpp @", inplace_idx)
    inplace_block = src[inplace_idx:clone_idx]
    assert (
        "Mark-StudioOwned -Path $LlamaCppDir" in inplace_block
    ), "in-place git-sync branch must call Mark-StudioOwned on success"
    assert (
        "$StudioHomeIsCustom" in inplace_block
    ), "in-place Mark-StudioOwned call should be gated on $StudioHomeIsCustom"


def test_setup_ps1_inplace_git_sync_asserts_studio_owned_before_mutation():
    """setup.ps1 in-place git-sync must Assert-StudioOwnedOrAbsent before any destructive git op."""
    src = SETUP_PS1.read_text(encoding = "utf-8")
    inplace_idx = src.index('Test-Path -LiteralPath (Join-Path $LlamaCppDir ".git")')
    clone_idx = src.index("Cloning llama.cpp @", inplace_idx)
    inplace_block = src[inplace_idx:clone_idx]
    assert (
        "Assert-StudioOwnedOrAbsent -Path $LlamaCppDir" in inplace_block
    ), "in-place git-sync must Assert-StudioOwnedOrAbsent before mutating $LlamaCppDir"
    guard_idx = inplace_block.index("Assert-StudioOwnedOrAbsent -Path $LlamaCppDir")
    git_idx = inplace_block.index("git -C $LlamaCppDir remote set-url")
    assert guard_idx < git_idx, "Assert-StudioOwnedOrAbsent must precede the first git mutation"


def _extract_check_health_function() -> str:
    src = INSTALL_SH.read_text(encoding = "utf-8")
    fn_start = src.index("_check_health() {")
    fn_end = src.index("\n}\n", fn_start) + 2
    return src[fn_start:fn_end]


def _run_check_health(expected_root_id: str, response_json: str) -> int:
    fn = _extract_check_health_function()
    script = (
        f"_EXPECTED_STUDIO_ROOT_ID={expected_root_id!r}\n"
        "_http_get() { printf '%s' \"$1\"; }\n"
        + fn.replace(
            '_resp=$(_http_get "http://127.0.0.1:$_port/api/health") || return 1',
            f"_resp={response_json!r}",
        )
        + "\n_check_health 8888\n"
        "echo rc=$?\n"
    )
    res = subprocess.run(
        ["bash", "-c", script],
        env = {"PATH": "/usr/bin:/bin"},
        text = True,
        capture_output = True,
    )
    rc_lines = [l for l in res.stdout.splitlines() if l.startswith("rc=")]
    return int(rc_lines[0].split("=")[1]) if rc_lines else res.returncode


def test_check_health_accepts_matching_studio_root_id():
    """Matching baked studio_root_id lets the launcher attach to its own backend."""
    expected_id = "a" * 64
    rc = _run_check_health(
        expected_id,
        f'{{"status":"healthy","service":"Unsloth UI Backend","studio_root_id":"{expected_id}"}}',
    )
    assert rc == 0, f"matching studio_root_id must allow attach (rc={rc})"


def test_check_health_rejects_mismatched_studio_root_id():
    """Mismatched studio_root_id rejects attach (workspace isolation across same-port Studios)."""
    expected_id = "a" * 64
    other_id = "b" * 64
    rc = _run_check_health(
        expected_id,
        f'{{"status":"healthy","service":"Unsloth UI Backend","studio_root_id":"{other_id}"}}',
    )
    assert rc != 0, "mismatched studio_root_id must reject attach (workspace isolation)"


def test_check_health_rejects_missing_studio_root_id_field():
    """A backend omitting studio_root_id must not be attached when an expected id is baked in."""
    expected_id = "a" * 64
    rc = _run_check_health(
        expected_id,
        '{"status":"healthy","service":"Unsloth UI Backend"}',
    )
    assert rc != 0, "missing studio_root_id field must reject attach"


def test_check_health_no_baked_id_accepts_any_healthy_backend():
    """Empty _EXPECTED_STUDIO_ROOT_ID falls back to legacy contract: accept any healthy Unsloth backend."""
    rc = _run_check_health(
        "",
        '{"status":"healthy","service":"Unsloth UI Backend","studio_root_id":"deadbeef"}',
    )
    assert rc == 0, "no baked id → accept any healthy Unsloth backend"


def test_check_health_rejects_non_unsloth_service():
    rc = _run_check_health(
        "",
        '{"status":"healthy","service":"Other UI Backend"}',
    )
    assert rc != 0, "non-Unsloth service must be rejected"


def test_check_health_handles_arbitrary_id_token():
    """A fully arbitrary 64-char hex install id must round-trip cleanly (hex-only, no JSON escapes)."""
    expected_id = "f0" + ("ed" * 31)  # 64 hex chars, not derived from any path
    rc = _run_check_health(
        expected_id,
        f'{{"status":"healthy","service":"Unsloth UI Backend","studio_root_id":"{expected_id}"}}',
    )
    assert rc == 0, "arbitrary 64-hex install id must round-trip cleanly (no JSON escape issue)"


def test_install_ps1_test_studio_health_verifies_studio_root_id():
    """install.ps1 Test-StudioHealth must compare studio_root_id against baked $_ExpectedStudioRootId."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    fn_start = src.index("function Test-StudioHealth")
    fn_end = src.index("\n}\n", fn_start) + 2
    fn = src[fn_start:fn_end]
    assert "studio_root_id" in fn, "Test-StudioHealth must inspect the studio_root_id field"
    assert (
        "$_ExpectedStudioRootId" in fn
    ), "Test-StudioHealth must compare against the install-time baked $_ExpectedStudioRootId"


def test_install_ps1_bakes_studio_root_id_into_launcher():
    """install.ps1 must persist a CSPRNG id at share/studio_install_id and bake it as $_ExpectedStudioRootId."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    assert "$_studioRootId" in src, "install.ps1 must compute $_studioRootId for the launcher"
    assert (
        '"share"' in src and "studio_install_id" in src
    ), "install.ps1 must persist the id at $StudioHome\\share\\studio_install_id"
    assert (
        "RandomNumberGenerator" in src
    ), "install.ps1 must seed the id from a CSPRNG (RandomNumberGenerator)"
    assert (
        "$_ExpectedStudioRootId" in src
    ), "install.ps1 must bake $_ExpectedStudioRootId into the launcher"


def test_health_endpoint_exposes_studio_root_id_not_raw_path():
    """/api/health must expose studio_root_id (hex digest), NOT the raw path (info disclosure on -H 0.0.0.0)."""
    main_py = REPO_ROOT / "studio" / "backend" / "main.py"
    src = main_py.read_text(encoding = "utf-8")
    health_idx = src.index('@app.get("/api/health")')
    # Slice up to the next top-level @app. so a growing body stays in scope.
    next_app_idx = src.find("\n@app.", health_idx + 1)
    if next_app_idx == -1:
        next_app_idx = len(src)
    health_block = src[health_idx:next_app_idx]
    assert '"studio_root_id"' in health_block, "/api/health must expose studio_root_id (hex digest)"
    assert (
        '"studio_root":' not in health_block
    ), "/api/health must NOT expose the raw studio_root path (information disclosure)"
    assert "_studio_root_id()" in health_block, "/api/health must call the _studio_root_id helper"


def test_install_sh_bakes_studio_root_id_into_launcher():
    """install.sh must persist the id at share/studio_install_id and bake it into the launcher for ALL modes."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    assert (
        "_css_studio_root_id" in src
    ), "install.sh must compute _css_studio_root_id for the launcher"
    assert (
        '_css_id_file="$_css_id_dir/studio_install_id"' in src
    ), "install.sh must persist the id at $STUDIO_HOME/share/studio_install_id"
    assert (
        "od -An -N32 -tx1 /dev/urandom" in src
    ), "install.sh must seed new ids from /dev/urandom (CSPRNG)"
    assert (
        "@@STUDIO_ROOT_ID@@" in src
    ), "install.sh must use @@STUDIO_ROOT_ID@@ placeholder in the launcher heredoc"
    assert (
        "s|@@STUDIO_ROOT_ID@@|$_css_studio_root_id|g" in src
    ), "install.sh must sed-substitute @@STUDIO_ROOT_ID@@ unconditionally (not just env-mode)"


def test_tauri_preflight_scrubs_studio_home_env():
    """Tauri CLI-spawn sites must env_remove UNSLOTH_STUDIO_HOME and STUDIO_HOME."""
    # PR #5341 split preflight into a submodule dir; read whichever shape is on disk.
    preflight_root = REPO_ROOT / "studio" / "src-tauri" / "src"
    preflight_paths = [
        preflight_root / "preflight.rs",
        *(preflight_root / "preflight").glob("*.rs"),
    ]
    preflight = "\n".join(p.read_text(encoding = "utf-8") for p in preflight_paths if p.exists())
    commands = (REPO_ROOT / "studio" / "src-tauri" / "src" / "commands.rs").read_text(
        encoding = "utf-8"
    )
    # Expect 2 scrubs in preflight (run_cli_probe + probe_cli_capability), 1 in commands.
    assert (
        preflight.count('cmd.env_remove("UNSLOTH_STUDIO_HOME")') >= 2
    ), "preflight must scrub UNSLOTH_STUDIO_HOME in both run_cli_probe and probe_cli_capability"
    assert (
        preflight.count('cmd.env_remove("STUDIO_HOME")') >= 2
    ), "preflight must scrub STUDIO_HOME in both run_cli_probe and probe_cli_capability"
    assert (
        'cmd.env_remove("UNSLOTH_STUDIO_HOME")' in commands
    ), "commands.rs check_install_status must scrub UNSLOTH_STUDIO_HOME"
    assert (
        'cmd.env_remove("STUDIO_HOME")' in commands
    ), "commands.rs check_install_status must scrub STUDIO_HOME"


def test_install_sh_shim_uses_atomic_replace():
    """install.sh shim install must use ln -sfn for atomic replace (rm+ln left a missing-shim window)."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    shim_idx = src.index('_shim_path="$_LOCAL_BIN/unsloth"')
    block = src[shim_idx : shim_idx + 1500]
    assert (
        'ln -sfn "$VENV_DIR/bin/unsloth" "$_shim_path"' in block
    ), "install.sh must use ln -sfn for atomic shim replacement"
    assert (
        'rm -f -- "$_shim_path"' not in block
    ), "the explicit rm + ln pair must be replaced by atomic ln -sfn"


def test_install_sh_create_shortcuts_seeds_id_from_csprng_with_python_fallback(tmp_path):
    """_create_shortcuts seeds ids from /dev/urandom (python3 secrets fallback) and is re-run idempotent."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    fn_start = src.index('_css_data_dir="$DATA_DIR"')
    block = src[fn_start : fn_start + 3000]
    urandom_idx = block.index("od -An -N32 -tx1 /dev/urandom")
    py_fallback_idx = block.index("python3 -c 'import secrets;", urandom_idx)
    assert (
        urandom_idx < py_fallback_idx
    ), "/dev/urandom must be tried before the python3 secrets fallback"
    # Non-empty id file check before generation is what makes re-runs idempotent.
    assert (
        'if [ ! -s "$_css_id_file" ]; then' in block
    ), "install.sh must skip id generation when the file already has content"

    # Behavioral check: run the generation block twice to confirm idempotence.
    studio_home = tmp_path / "studio"
    (studio_home / "share").mkdir(parents = True)
    gen_script = (
        f'STUDIO_HOME="{studio_home}"\n'
        '_css_id_dir="$STUDIO_HOME/share"\n'
        '_css_id_file="$_css_id_dir/studio_install_id"\n'
        # Replicate the generation block narrowly so it fails loud on contract drift.
        "gen() {\n"
        '    if [ ! -s "$_css_id_file" ]; then\n'
        '        _css_new_id=$(od -An -N32 -tx1 /dev/urandom 2>/dev/null | tr -d " \\n")\n'
        '        printf "%s" "$_css_new_id" > "$_css_id_file.$$.tmp"\n'
        '        mv "$_css_id_file.$$.tmp" "$_css_id_file"\n'
        "    fi\n"
        '    cat "$_css_id_file"\n'
        "}\n"
        "a=$(gen); b=$(gen)\n"
        '[ "$a" = "$b" ] || { echo MISMATCH; exit 1; }\n'
        'echo "ID=$a"\n'
        'echo "LEN=${#a}"\n'
    )
    res = subprocess.run(["bash", "-c", gen_script], text = True, capture_output = True)
    assert res.returncode == 0, res.stderr
    out = dict(line.split("=", 1) for line in res.stdout.strip().splitlines() if "=" in line)
    assert out.get("LEN") == "64", f"id must be 64 hex chars, got LEN={out.get('LEN')!r}"
    assert all(
        c in "0123456789abcdef" for c in out.get("ID", "")
    ), f"id must be lowercase hex, got {out.get('ID')!r}"


def test_install_sh_create_shortcuts_fails_fast_when_no_entropy():
    """With no entropy source, _create_shortcuts must `return 1` not bake an empty studio_root_id."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    fn_start = src.index('_css_data_dir="$DATA_DIR"')
    block = src[fn_start : fn_start + 3000]
    assert (
        "[WARN] Cannot create launcher: no entropy source for studio_install_id" in block
    ), "install.sh must warn when neither urandom nor python3 is available"
    assert (
        "[WARN] Cannot create launcher: failed to read" in block
    ), "install.sh must warn when the id file read produces no content"
    assert (
        block.count("return 1") >= 2
    ), "both the no-entropy branch and the empty-read branch must `return 1`"


def test_install_sh_bakes_installed_is_env_mode_flag_in_launcher():
    """install.sh must bake the install-time mode into the launcher so a sourced studio.conf can't flip it."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    assert (
        "_INSTALLED_IS_ENV_MODE='@@INSTALLED_IS_ENV_MODE@@'" in src
    ), "launcher heredoc must declare _INSTALLED_IS_ENV_MODE='@@INSTALLED_IS_ENV_MODE@@'"
    assert "_css_is_env_mode=false" in src, "install.sh must default _css_is_env_mode to false"
    assert (
        '[ "$_STUDIO_HOME_REDIRECT" = "env" ] && _css_is_env_mode=true' in src
    ), "install.sh must set _css_is_env_mode=true only when _STUDIO_HOME_REDIRECT=env"
    assert (
        "s|@@INSTALLED_IS_ENV_MODE@@|$_css_is_env_mode|g" in src
    ), "install.sh sed pipeline must substitute @@INSTALLED_IS_ENV_MODE@@"


def test_install_sh_launcher_gates_port_file_on_baked_flag_not_runtime_env():
    """Launcher PORT_FILE/LOCK_DIR must gate on baked $_INSTALLED_IS_ENV_MODE, not runtime $UNSLOTH_STUDIO_HOME."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    heredoc_start = src.index("cat > \"$_css_launcher\" << 'LAUNCHER_EOF'")
    heredoc_end = src.index("LAUNCHER_EOF\n", heredoc_start)
    heredoc = src[heredoc_start:heredoc_end]
    assert (
        'if [ "$_INSTALLED_IS_ENV_MODE" = "true" ]; then' in heredoc
    ), "launcher must gate PORT_FILE/LOCK_DIR on baked _INSTALLED_IS_ENV_MODE"
    port_block_start = heredoc.index('if [ "$_INSTALLED_IS_ENV_MODE" = "true" ]; then')
    port_block_end = heredoc.index("\nfi\n", port_block_start) + len("\nfi\n")
    port_block = heredoc[port_block_start:port_block_end]
    assert 'PORT_FILE="$DATA_DIR/studio.port"' in port_block
    assert (
        'if [ -n "${UNSLOTH_STUDIO_HOME:-}" ]; then\n    if command -v cksum' not in heredoc
    ), "launcher must NOT gate PORT_FILE on runtime UNSLOTH_STUDIO_HOME"

    def _run_launcher_gate(installed_flag: str, runtime_env: dict) -> str:
        # Run the LOCK_DIR/PORT_FILE init block in isolation.
        script = (
            f"_INSTALLED_IS_ENV_MODE={installed_flag!r}\n"
            "DATA_DIR=/tmp/test_data_dir\n"
            'LOCK_DIR="${XDG_RUNTIME_DIR:-/tmp}/unsloth-studio-launcher-$(id -u).lock"\n'
            'PORT_FILE=""\n' + port_block + '\necho "PORT_FILE=$PORT_FILE"\n'
        )
        env = {"PATH": "/usr/bin:/bin"}
        env.update(runtime_env)
        res = subprocess.run(
            ["bash", "-c", script],
            text = True,
            capture_output = True,
            env = env,
        )
        for line in res.stdout.splitlines():
            if line.startswith("PORT_FILE="):
                return line[len("PORT_FILE=") :]
        return ""

    # default-mode must keep PORT_FILE empty even if UNSLOTH_STUDIO_HOME leaks in.
    assert (
        _run_launcher_gate("false", {"UNSLOTH_STUDIO_HOME": "/tmp/leaked"}) == ""
    ), "default-mode launcher must keep PORT_FILE empty even with UNSLOTH_STUDIO_HOME in env"
    # env-mode must set PORT_FILE regardless of runtime env.
    assert (
        _run_launcher_gate("true", {}) == "/tmp/test_data_dir/studio.port"
    ), "env-mode launcher must set PORT_FILE based on baked DATA_DIR"


def test_main_py_studio_root_id_caches_at_module_load():
    """_studio_root_id() must read the id once at module load and reuse it (no per-poll FS/hash work)."""
    main_py = (REPO_ROOT / "studio" / "backend" / "main.py").read_text(encoding = "utf-8")
    assert (
        "_STUDIO_ROOT_ID_CACHE: str = _read_studio_install_id()" in main_py
    ), "main.py must populate _STUDIO_ROOT_ID_CACHE from _read_studio_install_id() at module load"
    fn_idx = main_py.index("def _studio_root_id() -> str:")
    next_def_idx = main_py.index("\ndef ", fn_idx + 1)
    fn_block = main_py[fn_idx:next_def_idx]
    assert (
        "return _STUDIO_ROOT_ID_CACHE" in fn_block
    ), "_studio_root_id() body must return the cached value"
    assert (
        "read_text(" not in fn_block and "hashlib" not in fn_block
    ), "_studio_root_id() must NOT do filesystem or hash work on every call"


def test_main_py_read_studio_install_id_validates_hex_and_handles_missing(tmp_path, monkeypatch):
    """_read_studio_install_id returns "" for absent/empty/non-hex/wrong-length ids, else the token."""
    import re

    pattern = re.compile(r"^[0-9a-f]{64}$")

    def _read(root: Path) -> str:
        # Mirror the implementation to pin the exact accepted contract.
        try:
            token = (root / "share" / "studio_install_id").read_text().strip()
        except (OSError, ValueError):
            return ""
        return token if pattern.fullmatch(token) else ""

    root = tmp_path / "studio"
    (root / "share").mkdir(parents = True)

    # Missing file -> empty
    assert _read(root) == ""

    id_file = root / "share" / "studio_install_id"
    # Empty file -> empty
    id_file.write_text("")
    assert _read(root) == ""
    # Non-hex content -> empty
    id_file.write_text("not-a-hex-id-just-text-padded-to-64-chars-zzzzzzzzzzzzzzzzzzzzzz")
    assert _read(root) == ""
    # Uppercase hex -> empty (must be lowercase)
    id_file.write_text("F" * 64)
    assert _read(root) == ""
    # Wrong length -> empty (32 chars, not 64)
    id_file.write_text("a" * 32)
    assert _read(root) == ""
    # Valid 64-char lowercase hex with surrounding whitespace -> stripped+accepted
    valid = "0123456789abcdef" * 4
    id_file.write_text(f"\n  {valid}  \n")
    assert _read(root) == valid


def test_llama_cpp_search_roots_handles_studio_root_oserror():
    """Root resolution must catch (ImportError, OSError, ValueError) from studio_root().
    Discovery (_find_llama_server_binary) and cleanup (_kill_orphaned_servers) both
    delegate to the shared _resolved_studio_root_and_is_legacy() classifier, which
    holds the handler so the two never disagree on which root is legacy."""
    llama_cpp = (
        REPO_ROOT / "studio" / "backend" / "core" / "inference" / "llama_cpp.py"
    ).read_text(encoding = "utf-8")

    def _method_body(name: str) -> str:
        # Whole method body (def to next sibling def) so the check survives growth.
        start = llama_cpp.index(f"def {name}")
        indent = " " * (start - llama_cpp.rfind("\n", 0, start) - 1)
        nxt = llama_cpp.find(f"\n{indent}def ", start + 1)
        return llama_cpp[start : nxt if nxt != -1 else len(llama_cpp)]

    assert (
        "except (ImportError, OSError, ValueError):"
        in _method_body("_resolved_studio_root_and_is_legacy")
    ), "_resolved_studio_root_and_is_legacy must catch (ImportError, OSError, ValueError) from studio_root()"
    # Both callers must route through the shared classifier so neither crashes.
    for caller in ("_find_llama_server_binary", "_kill_orphaned_servers"):
        assert "LlamaCppBackend._resolved_studio_root_and_is_legacy()" in _method_body(
            caller
        ), f"{caller} must resolve the install root via the shared classifier"


def test_install_sh_install_id_survives_symlinked_studio_home(tmp_path):
    """Regression: install id read from a file (not sha256(canonical_path)) agrees under a symlinked $STUDIO_HOME."""
    real = tmp_path / "realhome"
    real.mkdir()
    link = tmp_path / "linkhome"
    link.symlink_to(real)
    studio_home = real / ".unsloth" / "studio"
    (studio_home / "share").mkdir(parents = True)
    valid_id = "ab12" * 16
    (studio_home / "share" / "studio_install_id").write_text(valid_id)
    # Canonical and symlinked paths must see the SAME content (cat and read_text agree).
    raw_via_link = link / ".unsloth" / "studio" / "share" / "studio_install_id"
    raw_direct = studio_home / "share" / "studio_install_id"
    assert raw_via_link.read_text() == valid_id
    assert raw_direct.read_text() == valid_id
    # install.sh's `cat` sees the same.
    import subprocess as _sp

    res = _sp.run(["cat", str(raw_via_link)], capture_output = True, text = True)
    assert res.returncode == 0
    assert res.stdout == valid_id


def test_install_sh_substitutes_root_id_before_data_dir():
    """sed must bake the non-user-controlled placeholders before @@DATA_DIR@@ so a crafted $DATA_DIR isn't mutated."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    root_id_idx = src.index("s|@@STUDIO_ROOT_ID@@|$_css_studio_root_id|g")
    env_mode_idx = src.index("s|@@INSTALLED_IS_ENV_MODE@@|$_css_is_env_mode|g")
    data_dir_idx = src.index("s|@@DATA_DIR@@|$_sed_safe|g")
    assert root_id_idx < data_dir_idx, (
        "@@STUDIO_ROOT_ID@@ substitution must happen BEFORE @@DATA_DIR@@ "
        "(non-user-controlled placeholders first)"
    )
    assert (
        env_mode_idx < data_dir_idx
    ), "@@INSTALLED_IS_ENV_MODE@@ substitution must happen BEFORE @@DATA_DIR@@"


def test_install_sh_root_id_pass_does_not_mutate_user_data_dir(tmp_path):
    """A $DATA_DIR containing the literal @@STUDIO_ROOT_ID@@ must survive the placeholder-first sed passes."""
    src = INSTALL_SH.read_text(encoding = "utf-8")
    heredoc_start = src.index("cat > \"$_css_launcher\" << 'LAUNCHER_EOF'")
    heredoc_body_start = src.index("\n", heredoc_start) + 1
    heredoc_body_end = src.index("LAUNCHER_EOF\n", heredoc_start)
    template = src[heredoc_body_start:heredoc_body_end]
    launcher_path = tmp_path / "launch.sh"
    # template comes out of install.sh, so it carries whatever non-ASCII that
    # file holds and cp1252 cannot encode it back out.
    launcher_path.write_text(template, encoding = "utf-8")
    # sed order: root-id first, then data-dir.
    weird_data_dir = "/tmp/with-@@STUDIO_ROOT_ID@@/share"
    root_id = "deadbeef" * 8
    is_env = "true"
    script = f"""
sed -e "s|@@STUDIO_ROOT_ID@@|{root_id}|g" \\
    -e "s|@@INSTALLED_IS_ENV_MODE@@|{is_env}|g" \\
    "{launcher_path}" > "{launcher_path}.tmp" && mv "{launcher_path}.tmp" "{launcher_path}"
_sq_escaped=$(printf '%s' "{weird_data_dir}" | sed "s/'/'\\\\\\\\''/g")
_sed_safe=$(printf '%s' "$_sq_escaped" | sed 's/[\\\\&|]/\\\\&/g')
sed "s|@@DATA_DIR@@|$_sed_safe|g" "{launcher_path}" > "{launcher_path}.tmp" \\
    && mv "{launcher_path}.tmp" "{launcher_path}"
"""
    subprocess.run(["bash", "-c", script], check = True)
    # written as utf-8 just above, and the template carries U+2500.
    final = launcher_path.read_text(encoding = "utf-8")
    assert (
        f"DATA_DIR='{weird_data_dir}'" in final
    ), f"DATA_DIR must be preserved verbatim (no @@STUDIO_ROOT_ID@@ mutation); got: {final[:500]}"
    assert (
        f"_EXPECTED_STUDIO_ROOT_ID='{root_id}'" in final
    ), "STUDIO_ROOT_ID placeholder must still be substituted in the launcher heredoc"


def test_install_ps1_install_id_file_layout_matches_backend_read_path():
    """install.ps1 must write the id at share/studio_install_id where the backend reads it, idempotently."""
    src = INSTALL_PS1.read_text(encoding = "utf-8")
    id_idx = src.index('$_studioIdDir = Join-Path $StudioHome "share"')
    context = src[id_idx : id_idx + 1500]
    assert (
        '$_studioIdFile = Join-Path $_studioIdDir "studio_install_id"' in context
    ), "install.ps1 must persist the id at $StudioHome\\share\\studio_install_id"
    assert (
        "Test-Path -LiteralPath $_studioIdFile" in context
    ), "install.ps1 must skip id generation when the file already has content (re-run idempotence)"
    assert (
        "RandomNumberGenerator" in context and "GetBytes($_idBytes)" in context
    ), "install.ps1 must seed new ids from a CSPRNG (RandomNumberGenerator)"
    assert (
        "Move-Item -LiteralPath $_idTmp" in context
    ), "install.ps1 must atomic-rename the temp file into place to avoid half-written ids"