Problem
Same coverage run as the companion _cleanup.py/_private_files.py issue. lib/python/base_cli/_attach.py -- the Typer/Click attach adapter, per project context the newest and most structurally complex piece of base-cli -- is the lowest-covered file in the repo at 75% (87 of 378 statements missing, 26 of 124 branches missing).
The uncovered lines aren't scattered randomly; they concentrate in error-handling and partial-initialization-cleanup paths in _AttachedLifecycleResource:
__enter__ (lines 86-89, 120-125): the ConfigurationError/RuntimeDirectoryError -> click.UsageError/click.ClickException translation when context creation fails, and the except BaseException handler that records the failure outcome and calls self._finalize() when any part of __enter__ raises after the context was partially created. This second path is specifically the "something failed halfway through setup, now clean up what did get created" branch.initialize_factories (lines 143-150): the same ConfigurationError/RuntimeDirectoryError translation when an extension's context_factory or service_factory raises.- Roughly 15 additional smaller gaps spread through the file (dialect/command-path resolution helpers around lines 185-265, 312-325, 344-388, 403-414, 504-593) that look like edge-case branches in Click/Typer command-tree walking rather than a single coherent story -- lower priority than the two above, listed for completeness.
Why this matters
Adapter/attachment code is exactly where partial-initialization bugs are expensive: if __enter__ raises after acquiring some resources (a telemetry session was started, a context was created) but the cleanup-on-failure path (self._finalize()) has never been exercised by a test, a real failure in the field could leak the resource or mask the original error instead of surfacing it cleanly. This is the highest-risk kind of gap in an adapter that every attached Typer app depends on.
Proposed change
Add tests that force each of the four failure injection points above (a ConfigurationError/RuntimeDirectoryError from app._create_context, a BaseException after partial context creation, and the same two exception types from context_factory/service_factory), asserting: the correct Click exception type is raised, record_exception/_record_lifecycle_diagnostic is called with the right outcome, and _finalize() runs cleanup exactly once.
Acceptance criteria
Problem
Same coverage run as the companion
_cleanup.py/_private_files.pyissue.lib/python/base_cli/_attach.py-- the Typer/Click attach adapter, per project context the newest and most structurally complex piece of base-cli -- is the lowest-covered file in the repo at 75% (87 of 378 statements missing, 26 of 124 branches missing).The uncovered lines aren't scattered randomly; they concentrate in error-handling and partial-initialization-cleanup paths in
_AttachedLifecycleResource:__enter__(lines 86-89, 120-125): theConfigurationError/RuntimeDirectoryError->click.UsageError/click.ClickExceptiontranslation when context creation fails, and theexcept BaseExceptionhandler that records the failure outcome and callsself._finalize()when any part of__enter__raises after the context was partially created. This second path is specifically the "something failed halfway through setup, now clean up what did get created" branch.initialize_factories(lines 143-150): the sameConfigurationError/RuntimeDirectoryErrortranslation when an extension'scontext_factoryorservice_factoryraises.Why this matters
Adapter/attachment code is exactly where partial-initialization bugs are expensive: if
__enter__raises after acquiring some resources (a telemetry session was started, a context was created) but the cleanup-on-failure path (self._finalize()) has never been exercised by a test, a real failure in the field could leak the resource or mask the original error instead of surfacing it cleanly. This is the highest-risk kind of gap in an adapter that every attached Typer app depends on.Proposed change
Add tests that force each of the four failure injection points above (a
ConfigurationError/RuntimeDirectoryErrorfromapp._create_context, aBaseExceptionafter partial context creation, and the same two exception types fromcontext_factory/service_factory), asserting: the correct Click exception type is raised,record_exception/_record_lifecycle_diagnosticis called with the right outcome, and_finalize()runs cleanup exactly once.Acceptance criteria
_attach.pycoverage moves closer to the repo average (87%); the smaller edge-case gaps can be picked up opportunistically rather than requiring a specific target.