Replace linters and formatters with ruff

[mulkieran]

Related stratis-storage/project#64

Summary by CodeRabbit

• Chores
  • Migrated build and development tooling from multiple linters and formatters (pylint, black, isort) to a unified Ruff tool for improved development efficiency.
  • Updated CI/CD pipeline to use Ruff for consistent code linting and formatting checks across all builds.
  • Updated project configuration to support Ruff with Python 3.12 target version and standardized formatting rules.

[mulkieran]

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Walkthrough

This pull request migrates the codebase from multiple Python linting and formatting tools (pylint, black, isort) to a unified ruff configuration. CI workflows and build configuration files are updated to use ruff, pylint suppression comments are removed throughout the codebase, and tool-specific configuration files are deleted or replaced. Formatting adjustments and minor logic restructuring in select modules accompany the migration.

Changes

Cohort / File(s)	Summary
CI Configuration .github/workflows/main.yml	CI lint/format jobs updated to invoke ruff instead of pylint, black, and isort; PYTHONPATH=./src environment variable removed from lint task.
Build & Tool Configuration Makefile, .isort.cfg, pyproject.toml	Makefile targets (lint, fmt, fmt-travis) replaced to use ruff check and ruff format commands; .isort.cfg deleted; pyproject.toml adds ruff configuration with target Python 3.12, line length 88, and import sorting rules.
Script Code scripts/monitor_dbus_signals.py, scripts/monitor_metadata.py	Pylint suppression comments removed; multi-line constructor signatures simplified; minor string quoting style adjustments for consistency.
Test Certificate Files stratis_cli_cert.py, stratisd_cert.py	Pylint suppress directives (too-many-public-methods, too-many-lines) removed from class and module declarations; class definition formatting simplified; dd command string quoting adjusted.
Test Infrastructure test_harness.py, testlib/dbus.py, testlib/infra.py, testlib/utils.py	Pylint disable comments removed across class declarations and function signatures; testlib/infra.py refactors error-message string formatting and restructures control flow (elif replaces nested else block); blank line inserted in testlib/utils.py between docstring and imports; specific return-code comparisons annotated with # noqa PLR2004.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 60.53% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and accurately summarizes the main objective of the changeset: replacing pylint, black, and isort with ruff across the repository's configuration, CI, and codebase.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 2

🧹 Nitpick comments (2)

pyproject.toml (1)

5-6: Use extend-select = ["PL"] to add Pylint rules while preserving default linting.

At Line 6, select = ["PL"] replaces Ruff's default rule set (E4, E7, E9, F) with only Pylint rules, narrowing lint coverage. Unless this narrowing is intentional, use extend-select to add Pylint rules while keeping the defaults.

Suggested config adjustment

 [tool.ruff.lint]
-select = ["PL"]
+extend-select = ["PL"]

🤖 Prompt for AI Agents

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

In `@pyproject.toml` around lines 5 - 6, The current Ruff config under
[tool.ruff.lint] uses select = ["PL"], which replaces Ruff's default rule set;
change this to extend-select = ["PL"] so Pylint rules are added without losing
defaults. Locate the [tool.ruff.lint] section and replace the select key with
extend-select (or add extend-select alongside existing defaults) to preserve
default rule groups (E4, E7, E9, F) while enabling the "PL" rules.

testlib/infra.py (1)

613-620: Fix Ruff noqa directive syntax to use colon for scoped suppression.

Lines 613 and 620 use # noqa PLR2004 (space separator), which is the blanket form. Use # noqa: PLR2004 (with colon) to keep suppression precise and scoped to the specific code violations.

Proposed fix

-            if self.trace.returncode == 3:  # noqa PLR2004
+            if self.trace.returncode == 3:  # noqa: PLR2004
...
-            if self.trace.returncode == 4:  # noqa PLR2004
+            if self.trace.returncode == 4:  # noqa: PLR2004

🤖 Prompt for AI Agents

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

In `@testlib/infra.py` around lines 613 - 620, Update the inline Ruff suppression
comments on the return-code checks to use the scoped form with a colon; locate
the two occurrences where the code checks self.trace.returncode (the branches
checking == 3 and == 4) and change "# noqa PLR2004" to "# noqa: PLR2004" so the
suppression is properly scoped to those lines.

🤖 Prompt for all review comments with AI agents

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

Inline comments:
In `@scripts/monitor_dbus_signals.py`:
- Around line 419-420: The except blocks currently append raw exception objects
to _CALLBACK_ERRORS (e.g., "except Exception as exc:
_CALLBACK_ERRORS.append(exc)"); change these to append a string representation
(preferably the full traceback) so later reporting/joining is reliable — for
example use traceback.format_exc() or str(exc) and append that string to
_CALLBACK_ERRORS; update all three occurrences that append exc (the except
blocks that reference exc at the three noted spots) and add an import for
traceback if you choose format_exc().

In `@test_harness.py`:
- Around line 45-46: In _LogBlockdev.__str__, replace the bare "except:" that
returns `f"could not gather output of {self.cmd}"` with "except Exception:" so
only regular exceptions are caught (allowing KeyboardInterrupt/SystemExit to
propagate); update the except clause in the __str__ method to use "except
Exception:" and keep the existing return behavior and message using self.cmd.

---

Nitpick comments:
In `@pyproject.toml`:
- Around line 5-6: The current Ruff config under [tool.ruff.lint] uses select =
["PL"], which replaces Ruff's default rule set; change this to extend-select =
["PL"] so Pylint rules are added without losing defaults. Locate the
[tool.ruff.lint] section and replace the select key with extend-select (or add
extend-select alongside existing defaults) to preserve default rule groups (E4,
E7, E9, F) while enabling the "PL" rules.

In `@testlib/infra.py`:
- Around line 613-620: Update the inline Ruff suppression comments on the
return-code checks to use the scoped form with a colon; locate the two
occurrences where the code checks self.trace.returncode (the branches checking
== 3 and == 4) and change "# noqa PLR2004" to "# noqa: PLR2004" so the
suppression is properly scoped to those lines.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: f4003422-25d8-4dcb-9ae7-1c315b9b3fd4

📥 Commits

Reviewing files that changed from the base of the PR and between 4136e93 and 5e3b979.

📒 Files selected for processing (12)

• .github/workflows/main.yml
• .isort.cfg
• Makefile
• pyproject.toml
• scripts/monitor_dbus_signals.py
• scripts/monitor_metadata.py
• stratis_cli_cert.py
• stratisd_cert.py
• test_harness.py
• testlib/dbus.py
• testlib/infra.py
• testlib/utils.py

💤 Files with no reviewable changes (1)

• .isort.cfg