fix: resolve ty type diagnostics and add CI quality gates

[raballew]

Summary

• Fix 41 ty type checker diagnostics across Python driver packages (power_pdu, sdwire, dutlink, and others) by correcting type annotations, replacing assert with explicit None checks, and using proper types like FrameType
• Add CI quality gates: ty type checking job in lint workflow and diff-coverage enforcement (80% threshold on changed lines) in test workflow
• Add tests for defensive type guards in CLI common utilities

Test plan

• Verify make ty passes locally with zero diagnostics on the fixed packages
• Verify make test passes across all affected packages
• Confirm the new type-check-python CI job runs successfully on PRs touching Python code
• Confirm diff-cover enforcement activates on PRs and reports coverage on changed lines

🤖 Generated with Claude Code

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR adds test coverage for parameter parsing and error handling, improves type annotations in signal handler code, enhances mitmproxy driver tests with runtime type assertions, replaces runtime assertions with proper exception handling in the login command, and adds type-checker suppression comments across multiple test and driver files.

Changes

Cohort / File(s)	Summary
CLI Test Coverage jumpstarter_cli/common_test.py, jumpstarter_cli/completion_test.py	Added two test cases for DurationParamType parsing (integer input and unsupported type) and one test for unsupported shell completion lookup failure.
CLI Error Handling jumpstarter_cli/login.py	Replaced assertions with explicit runtime checks that raise click.ClickException when config.token is None, providing user-facing error messages instead of assertion failures.
Mitmproxy Driver Test Enhancements jumpstarter_driver_mitmproxy/driver_test.py	Added imports for config classes and runtime type assertions verifying that driver configuration attributes are correct instances before continuing with existing default-path and port/host checks.
Type-Checker Suppressions jumpstarter_driver_gpiod/driver_test.py, jumpstarter_driver_renode/driver.py, jumpstarter_driver_renode/driver_test.py	Added # ty: ignore[...] comments on mock assertions and type-annotated assignments to suppress type-checker diagnostics without changing runtime behavior or logic.
Type Annotations jumpstarter_driver_pyserial/nvdemux/manager.py	Refined type annotation for the inner make_handler factory to return `Callable[[int, FrameType

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• Add Renode emulator driver for embedded target simulation #533: Directly modifies the same Renode driver files with type-checker ignore comments on variable assignments.
• Improve j commands exception handling #328: Modifies error handling and validation in login.py, complementing the assertion-to-exception conversion in this PR.

Suggested reviewers

• kirkbrauer
• mangelajo

Poem

🐰 Tests now shine with coverage bright,
Type checkers quieted with pragmatic might,
Errors speak in user-friendly tongue,
No more silent assertions left unsung,
The CLI hops forward, sturdy and sound!

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix: resolve ty type diagnostics and add CI quality gates' clearly describes the main changes: fixing type-checker diagnostics and adding CI checks.
Description check	✅ Passed	The description is well-detailed and directly related to the changeset, outlining the key changes, CI improvements, and test additions across the pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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🧹 Nitpick comments (1)

python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/nvdemux/manager.py (1)

162-177: Consider adding explicit type annotation to frame parameter.

While the type checker can infer the frame type from the outer function's return type, adding an explicit annotation would improve clarity and consistency with the explicitly-typed return signature:

def handler(signum: int, frame: FrameType | None):

This makes the handler signature immediately clear without needing to reference the outer function's return type.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In
`@python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/nvdemux/manager.py`
around lines 162 - 177, The handler callback currently defines def
handler(signum: int, frame): without an explicit frame type; update the
signature of handler to explicitly annotate frame as FrameType | None (e.g., def
handler(signum: int, frame: FrameType | None):) and ensure FrameType is imported
(from types import FrameType) or use typing.Optional if needed so the annotation
is recognized; keep the rest of handler logic (cleanup via
cls._instance._cleanup(), restoring cls._original_sigterm_handler /
cls._original_sigint_handler, and os.kill(os.getpid(), signum)) unchanged.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In
`@python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/nvdemux/manager.py`:
- Around line 162-177: The handler callback currently defines def
handler(signum: int, frame): without an explicit frame type; update the
signature of handler to explicitly annotate frame as FrameType | None (e.g., def
handler(signum: int, frame: FrameType | None):) and ensure FrameType is imported
(from types import FrameType) or use typing.Optional if needed so the annotation
is recognized; keep the rest of handler logic (cleanup via
cls._instance._cleanup(), restoring cls._original_sigterm_handler /
cls._original_sigint_handler, and os.kill(os.getpid(), signum)) unchanged.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: acda1192-c385-41f4-9336-5f1006e45b0c

📥 Commits

Reviewing files that changed from the base of the PR and between fcbbfbf and 339f3b5.

📒 Files selected for processing (8)

• python/packages/jumpstarter-cli/jumpstarter_cli/common_test.py
• python/packages/jumpstarter-cli/jumpstarter_cli/completion_test.py
• python/packages/jumpstarter-cli/jumpstarter_cli/login.py
• python/packages/jumpstarter-driver-gpiod/jumpstarter_driver_gpiod/driver_test.py
• python/packages/jumpstarter-driver-mitmproxy/jumpstarter_driver_mitmproxy/driver_test.py
• python/packages/jumpstarter-driver-pyserial/jumpstarter_driver_pyserial/nvdemux/manager.py
• python/packages/jumpstarter-driver-renode/jumpstarter_driver_renode/driver.py
• python/packages/jumpstarter-driver-renode/jumpstarter_driver_renode/driver_test.py