Share the bounded read in scaffold and the blocked exit in doctor

autoform_cli/doctor.py

@@ -103,10 +103,7 @@ def diagnose_project(
         reason = _sanitize_issues(error.issues, paths)
         checks.append(DoctorCheck("runtime", False, "canonical graph is invalid"))
         checks.append(DoctorCheck("graph", False, reason))
-        checks.append(DoctorCheck("references", False, "not checked because graph validation failed"))
-        checks.append(DoctorCheck("audit", False, "not checked because graph validation failed"))
-        checks.append(_blocked_lean_check("graph validation failed", lean_root))
-        return _result(checks)
+        return _blocked_result(checks, "graph validation failed", lean_root=lean_root)
 
     resolved_lean_root, lean_root_valid = _resolve_lean_root(lean_root)
     try:
@@ -128,10 +125,7 @@ def diagnose_project(
 
     if runtime is None:
         checks.append(DoctorCheck("graph", False, "not summarized because runtime projection failed"))
-        checks.append(DoctorCheck("references", False, "not checked because runtime projection failed"))
-        checks.append(DoctorCheck("audit", False, "not checked because runtime projection failed"))
-        checks.append(_blocked_lean_check("runtime projection failed", lean_root))
-        return _result(checks)
+        return _blocked_result(checks, "runtime projection failed", lean_root=lean_root)
 
     checks.append(
         DoctorCheck(

autoform_cli/scaffold.py

@@ -575,6 +575,20 @@ def _is_link(metadata: os.stat_result) -> bool:
     return stat.S_ISLNK(metadata.st_mode) or bool(attributes & reparse)
 
 
+def _read_at_most(descriptor: int, size: int) -> bytes:
+    """Read from *descriptor* until end of file or *size* bytes, whichever is first."""
+
+    chunks: list[bytes] = []
+    remaining = size
+    while remaining:
+        chunk = os.read(descriptor, min(64 * 1024, remaining))
+        if not chunk:
+            break
+        chunks.append(chunk)
+        remaining -= len(chunk)
+    return b"".join(chunks)
+
+
 def _read_bounded_regular_file(
     path: Path,
     *,
@@ -609,15 +623,7 @@ def _read_bounded_regular_file(
         ):
             raise ScaffoldError([f"the {label} changed while it was being read"])
 
-        chunks: list[bytes] = []
-        remaining = limit + 1
-        while remaining:
-            chunk = os.read(descriptor, min(64 * 1024, remaining))
-            if not chunk:
-                break
-            chunks.append(chunk)
-            remaining -= len(chunk)
-        content = b"".join(chunks)
+        content = _read_at_most(descriptor, limit + 1)
         after_identity = _node_identity(os.fstat(descriptor))
         named_identity = _node_identity(os.stat(path, follow_symlinks=False))
         if (
@@ -818,18 +824,11 @@ def _read_gitignore_descriptor(
             [f"refusing to merge .gitignore larger than {_MAX_GITIGNORE_BYTES} bytes"]
         )
     os.lseek(descriptor, 0, os.SEEK_SET)
-    chunks: list[bytes] = []
-    total = 0
-    while True:
-        chunk = os.read(descriptor, min(64 * 1024, _MAX_GITIGNORE_BYTES - total + 1))
-        if not chunk:
-            break
-        chunks.append(chunk)
-        total += len(chunk)
-        if total > _MAX_GITIGNORE_BYTES:
-            raise ScaffoldError(
-                [f"refusing to merge .gitignore larger than {_MAX_GITIGNORE_BYTES} bytes"]
-            )
+    content = _read_at_most(descriptor, _MAX_GITIGNORE_BYTES + 1)
+    if len(content) > _MAX_GITIGNORE_BYTES:
+        raise ScaffoldError(
+            [f"refusing to merge .gitignore larger than {_MAX_GITIGNORE_BYTES} bytes"]
+        )
     after = os.fstat(descriptor)
     named = os.stat(path, follow_symlinks=False)
     opened_identity = _node_identity(opened)
@@ -844,7 +843,7 @@ def _read_gitignore_descriptor(
         != _cross_interface_identity(opened_identity)
     ):
         raise ScaffoldError([f".gitignore changed while it was being inspected: {path}"])
-    return b"".join(chunks), named_identity
+    return content, named_identity
 
 
 def _gitignore_suffix(existing: bytes, required: bytes) -> bytes | None:

tests/test_scaffold.py

@@ -732,8 +732,6 @@ def test_no_ci_rather_than_a_guessed_pin(tmp_path: Path, monkeypatch: pytest.Mon
     `facebookresearch/autoform-bot@main`, a commit predating the CLI, and every
     project scaffolded that way got CI that died at the first step.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(scaffold_module, "plugin_pin", lambda _templates=None: ("", ""))
     result = scaffold_module.scaffold_project(tmp_path, title="Finite Flat")
 
@@ -773,8 +771,6 @@ def test_a_ref_alone_restores_ci(tmp_path: Path, monkeypatch: pytest.MonkeyPatch
     supplied too, following that instruction would still yield no CI, and the
     fail-closed behaviour would be indistinguishable from a broken flag.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(scaffold_module, "plugin_pin", lambda _templates=None: ("", ""))
     result = scaffold_module.scaffold_project(tmp_path, title="Finite Flat", autoform_ref="2" * 40)
 
@@ -826,8 +822,6 @@ def test_a_mutable_ref_is_refused(ref: str, tmp_path: Path, monkeypatch: pytest.
     which is how projects got a build with no `autoform` command in the first
     place. The scaffold refuses instead of writing CI that rots.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(scaffold_module, "plugin_pin", lambda _templates=None: ("", ""))
     with pytest.raises(scaffold_module.ScaffoldError) as caught:
         scaffold_module.scaffold_project(tmp_path, title="Finite Flat", autoform_ref=ref)
@@ -840,8 +834,6 @@ def test_a_mutable_ref_is_refused(ref: str, tmp_path: Path, monkeypatch: pytest.
 def test_an_explicit_source_overrides_the_default(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(scaffold_module, "plugin_pin", lambda _templates=None: ("", ""))
     scaffold_module.scaffold_project(
         tmp_path,
@@ -900,8 +892,6 @@ def test_an_unsafe_explicit_source_is_refused_without_persisting_it(
 def test_an_unsafe_plugin_pin_fails_closed_without_persisting_credentials(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     secret_source = "https://token:secret@example.test/autoform.git"
     monkeypatch.setattr(
         scaffold_module,
@@ -922,8 +912,6 @@ def test_an_unsafe_plugin_pin_fails_closed_without_persisting_credentials(
 
 
 def test_plugin_pin_is_empty_outside_a_checkout(monkeypatch: pytest.MonkeyPatch) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(scaffold_module, "_git", lambda *args, **kwargs: None)
     monkeypatch.setattr(scaffold_module, "_marketplace_checkout", lambda: None)
     assert scaffold_module.plugin_pin() == ("", "")
@@ -993,8 +981,6 @@ def test_an_installed_plugin_pins_from_the_marketplace_checkout(
     is asked for a commit that nothing on their machine reports. That is a real
     provenance record, not the guess `plugin_pin` refuses to make.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     _, _, head = _fake_plugin_install(tmp_path, monkeypatch)
 
     assert scaffold_module.plugin_pin() == (
@@ -1077,8 +1063,6 @@ def test_plugin_pin_prefers_canonical_upstream_over_a_containing_fork_origin(
 def test_plugin_pin_fails_closed_when_checkout_or_copy_bytes_do_not_match_head(
     changed: str, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     checkout, copied, _ = _fake_plugin_install(tmp_path, monkeypatch)
     selected = checkout if changed.startswith("checkout-") else copied
     if changed == "copy-executable-mode":
@@ -1144,8 +1128,6 @@ def test_direct_checkout_pin_ignores_unrelated_untracked_files(
 def test_plugin_pin_accepts_umask_permission_noise(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     checkout, copied, head = _fake_plugin_install(tmp_path, monkeypatch)
     for root in (checkout, copied):
         (root / "autoform_cli" / "scaffold.py").chmod(0o664)
@@ -1164,8 +1146,6 @@ def test_an_unrelated_marketplace_checkout_is_not_trusted(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
     """A location that is not Autoform would pin CI to somebody else's repo."""
-    from autoform_cli import scaffold as scaffold_module
-
     checkout, _, _ = _fake_plugin_install(tmp_path, monkeypatch)
     (checkout / "autoform_cli" / "scaffold.py").unlink()
 
@@ -1183,8 +1163,6 @@ def test_a_copy_inside_an_unrelated_repository_is_not_its_provenance(
     project, so its CI would be pinned to install the project instead of
     Autoform, at a sha that moves with every commit the author makes.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     project = tmp_path / "their-project"
     _repository(project, "https://github.com/someone/their-project.git")
     installed = project / ".venv/lib/python3.12/site-packages"
@@ -1200,8 +1178,6 @@ def test_a_branch_in_the_marketplace_checkout_is_refused(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
     """Whatever the provenance says, only a full sha may reach the workflows."""
-    from autoform_cli import scaffold as scaffold_module
-
     checkout, _, _ = _fake_plugin_install(tmp_path, monkeypatch)
 
     def fake_git(*args: str, root: Path | None = None) -> str | None:
@@ -1220,8 +1196,6 @@ def test_a_symlinked_subdirectory_cannot_redirect_the_scaffold(tmp_path: Path) -
     `project/blueprint` pointing elsewhere sent the whole vault outside the
     project, and --force would have overwritten whatever it found there.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     project = tmp_path / "project"
     outside = tmp_path / "outside"
     project.mkdir()
@@ -1237,8 +1211,6 @@ def test_a_symlinked_subdirectory_cannot_redirect_the_scaffold(tmp_path: Path) -
 
 def test_a_dangling_destination_symlink_cannot_redirect_the_scaffold(tmp_path: Path) -> None:
     """`Path.exists()` is false for a link whose outside target is absent."""
-    from autoform_cli import scaffold as scaffold_module
-
     project = tmp_path / "project"
     outside = tmp_path / "outside" / "mkdocs.yml"
     project.mkdir()
@@ -1252,17 +1224,13 @@ def test_a_dangling_destination_symlink_cannot_redirect_the_scaffold(tmp_path: P
 
 def test_a_title_with_a_colon_stays_one_yaml_key(tmp_path: Path) -> None:
     """`site_name: Algebra: Foundations` is a nested mapping, not a title."""
-    from autoform_cli import scaffold as scaffold_module
-
     scaffold_module.scaffold_project(tmp_path, title="Algebra: Foundations")
 
     config = (tmp_path / "mkdocs.yml").read_text(encoding="utf-8")
     assert 'site_name: "Algebra: Foundations"' in config
 
 
 def test_a_quoted_title_is_escaped_not_just_wrapped(tmp_path: Path) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     scaffold_module.scaffold_project(tmp_path, title='The "Hard" Case')
 
     config = (tmp_path / "mkdocs.yml").read_text(encoding="utf-8")
@@ -1277,8 +1245,6 @@ def test_a_source_without_a_ref_does_not_borrow_this_checkouts_commit(
     Keeping the inferred ref while replacing the source emitted
     `git+other.git@our-sha`, which does not resolve in `other`.
     """
-    from autoform_cli import scaffold as scaffold_module
-
     monkeypatch.setattr(
         scaffold_module,
         "plugin_pin",
@@ -1293,8 +1259,6 @@ def test_a_source_without_a_ref_does_not_borrow_this_checkouts_commit(
 
 
 def test_a_source_with_its_own_ref_is_honoured(tmp_path: Path) -> None:
-    from autoform_cli import scaffold as scaffold_module
-
     scaffold_module.scaffold_project(
         tmp_path,
         title="Probe",