Add custom exception hierarchy (#219) by jtdub · Pull Request #239 · netdevops/hier_config

jtdub · 2026-03-26T03:40:35Z

Summary

Added HierConfigError as the base exception for all hier_config errors
Added DriverNotFoundError (replaces ValueError in get_hconfig_driver/get_hconfig_view)
Added InvalidConfigError (replaces ValueError for malformed config/banner parsing)
Added IncompatibleDriverError (replaces ValueError in WorkflowRemediation for mismatched drivers)
Reparented DuplicateChildError under HierConfigError
All new exceptions exported from hier_config.__init__

Test plan

New tests/unit/test_exceptions.py with 6 tests covering hierarchy, inheritance, and all raise sites
Updated existing tests in test_constructors.py and test_workflows.py to catch specific exception types
Full lint + test suite passes (poetry run ./scripts/build.py lint-and-test)

Closes #219

🤖 Generated with Claude Code

Add HierConfigError as the base exception with DriverNotFoundError, InvalidConfigError, IncompatibleDriverError, and reparent DuplicateChildError under it. Replace generic ValueError/TypeError raises in constructors and workflows with specific exception types. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

This PR introduces a first-class exception hierarchy for hier_config so callers can catch specific failure modes instead of generic ValueErrors, and updates raise sites/tests accordingly.

Changes:

Added HierConfigError base plus DriverNotFoundError, InvalidConfigError, and IncompatibleDriverError; reparented DuplicateChildError.
Switched key raise sites in constructors/workflows from ValueError to the new custom exceptions.
Updated/added unit tests and exported the new exceptions from hier_config.__init__.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/unit/test_workflows.py	Updates expected exception for driver mismatch in `WorkflowRemediation`.
tests/unit/test_exceptions.py	Adds new unit tests covering the exception hierarchy and raise sites.
tests/unit/test_constructors.py	Updates constructor-related tests to expect new exception types.
hier_config/workflows.py	Raises `IncompatibleDriverError` for mismatched drivers.
hier_config/exceptions.py	Defines the new exception hierarchy and reparents `DuplicateChildError`.
hier_config/constructors.py	Raises `DriverNotFoundError` / `InvalidConfigError` at relevant failure points.
hier_config/init.py	Re-exports new exceptions at the package top level.
CHANGELOG.md	Documents the new exception hierarchy in Unreleased notes.

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Copilot · 2026-03-26T03:45:02Z

hier_config/workflows.py

        if running_config.driver.__class__ is not generated_config.driver.__class__:
            message = "The running and generated configs must use the same driver."
-            raise ValueError(message)
+            raise IncompatibleDriverError(message)


The WorkflowRemediation docstring still documents Raises: ValueError for driver mismatches, but the implementation now raises IncompatibleDriverError. Please update the docstring to match the new exception type so API docs stay accurate.

Copilot · 2026-03-26T03:45:02Z

tests/unit/test_workflows.py

    generated_config = get_hconfig(Platform.JUNIPER_JUNOS, "dummy_config")



There’s an outdated comment just above this block that says the test ensures a ValueError is raised for mismatched drivers, but the expectation is now IncompatibleDriverError. Please update/remove that comment to keep the test intent accurate.

Copilot · 2026-03-26T03:45:03Z

CHANGELOG.md

+- Custom exception hierarchy: `HierConfigError` base, `DriverNotFoundError`,
+  `InvalidConfigError`, `IncompatibleDriverError` (#219). `DuplicateChildError`
+  reparented under `HierConfigError`.


This changelog entry describes a breaking behavior change (replacing ValueError with custom exceptions and reparenting DuplicateChildError). To match the existing changelog structure (e.g., other breaking renames listed under "Changed"), consider moving this bullet to the "### Changed" section or explicitly calling out that it’s breaking in the "Added" entry.

Add HierConfigError as the base exception with DriverNotFoundError, InvalidConfigError, IncompatibleDriverError, and reparent DuplicateChildError under it. Replace generic ValueError/TypeError raises in constructors and workflows with specific exception types. Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

@staticmethod

* Add CODEOWNERS file Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Add Literal type constraint for cisco_style_text() style parameter (#189) (#240) Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Drop v2 migration utilities, rename to load_driver_rules/load_tag_rules, and reorganize tests (#221) Remove v2-to-v3 platform mapping functions and constants. Rename load_hconfig_v2_options to load_driver_rules and load_hconfig_v2_tags to load_tag_rules, preserving dict-based driver extension for Nautobot Golden Config compatibility. Reorganize test suite into unit/, integration/, and benchmarks/ directories mirroring the source code structure. Split the 2079-line test_hier_config.py into focused files by module (test_root.py, test_child.py, test_children.py). Separate driver remediation scenario tests into integration/ and unit tests into unit/platforms/. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Fix load_tag_rules: use _collect_match_rules and correct return type Replace inline match-rule collection with existing _collect_match_rules helper for consistency. Simplify return type from tuple[TagRule] | tuple[TagRule, ...] to tuple[TagRule, ...]. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * update gha to test against the next branch * Fix __hash__/__eq__ inconsistency in HConfigChild (#185) (#236) * Fix __hash__/__eq__ inconsistency in HConfigChild (#185) __hash__ included new_in_config and order_weight but __eq__ intentionally excluded them, violating the Python invariant that a == b implies hash(a) == hash(b). __eq__ also checked tags but __hash__ did not include them. Align __hash__ to use the same fields as __eq__: text, tags, and children. Add five tests covering each dimension of the inconsistency and its practical impact on set deduplication and dict key lookup. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * Fix pre-existing lint errors in next branch - test_benchmarks.py: replace append loops with extend (PERF401), add @staticmethod to methods that don't use self (PLR6301), suppress intentional print calls with noqa: T201 - test_child.py: suppress pylint too-many-lines (C0302) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com> * Move Huawei VRP tests to integration test directory Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Rename inconsistent public APIs (#216) - tags_add()/tags_remove() → add_tags()/remove_tags() - cisco_style_text() → indented_text() - dump_simple() → to_lines() - config_to_get_to() → remediation() - depth() method → depth property - Rename private helpers _config_to_get_to/_left/_right accordingly Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Add custom exception hierarchy (#219) (#239) Add HierConfigError as the base exception with DriverNotFoundError, InvalidConfigError, IncompatibleDriverError, and reparent DuplicateChildError under it. Replace generic ValueError/TypeError raises in constructors and workflows with specific exception types. Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * Add Literal type constraint for indented_text() style parameter (#189) (#241) Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

jtdub requested a review from aedwardstx as a code owner March 26, 2026 03:40

jtdub requested a review from Copilot March 26, 2026 03:41

Copilot started reviewing on behalf of jtdub March 26, 2026 03:42 View session

jtdub merged commit 1568211 into next Mar 26, 2026
7 checks passed

jtdub deleted the issue-219-exception-hierarchy branch March 26, 2026 03:44

Copilot AI reviewed Mar 26, 2026

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Add custom exception hierarchy (#219)#239

Add custom exception hierarchy (#219)#239
jtdub merged 1 commit intonextfrom
issue-219-exception-hierarchy

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		generated_config = get_hconfig(Platform.JUNIPER_JUNOS, "dummy_config")

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jtdub commented Mar 26, 2026

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