Preserve pre-existing user templates on save

[amilcarlucas]

When saving a component template to the user templates file, existing templates for other component types were silently overwritten. Now the file is read before writing and merged so only the saved component's entry is updated while all others are retained.

Also adds broader OSError/Exception handling to _load_system_templates and _load_user_templates so read failures degrade gracefully to an empty dict instead of propagating an unhandled exception.

[Copilot]

Pull request overview

This PR updates vehicle component template persistence so saving a template updates only the relevant component entry while retaining other existing templates in the same JSON file, and improves robustness when reading template files by handling more I/O failure modes gracefully.

Changes:

• Merge existing user templates from disk when writing updated component templates to avoid overwriting other component types.
• Add broader OSError / Exception handling in system/user template load helpers to degrade to {} on read failures.
• Add a regression test ensuring pre-existing user component templates are preserved on save.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
ardupilot_methodic_configurator/backend_filesystem_vehicle_components.py	Reads existing templates before writing and expands error handling in template loaders.
tests/test_backend_filesystem_vehicle_components.py	Adds a test verifying saving one component template preserves other user templates.

Comments suppressed due to low confidence (1)

ardupilot_methodic_configurator/backend_filesystem_vehicle_components.py:244

• In save_component_templates_to_file() when save_component_to_system_templates is enabled, filepath is always set to the package resource path (.../vehicle_templates/system_vehicle_components_template.json). If that file doesn’t exist (or the resource directory is read-only), the code still proceeds to write to that resource path because there’s no fallback assignment to os_path.join(templates_dir, templates_filename). This can cause writes to fail or go to the wrong location, and it also means existing system templates in the fallback location won’t be loaded/merged. Set filepath (and existing_templates) to the default templates directory when the local resource file isn’t present, before opening the file for writing.

                local_dir = importlib_files("ardupilot_methodic_configurator") / "vehicle_templates"
                filepath = str(local_dir / templates_filename)
                if os_path.exists(filepath):
                    existing_templates = self._load_system_templates(filepath)
            except (OSError, ValueError) as e:
                logging_debug("Failed to check local template file: %s", e)
                # Fall back to default templates_dir
        else:

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[Copilot]

Typo/grammar in the new comment: “with local a local git repository” should be corrected (duplicate “local”), and “github” should be capitalized as “GitHub”.

Suggested change

	# Save to "developer" system templates file, only for AMC developers with local a local git repository
	# copy of the software who want to add new templates to the system templates file in their local git
	# repository and create a github pull-request with the newly added component templates.
	# Save to "developer" system templates file, only for AMC developers with a local git repository
	# copy of the software who want to add new templates to the system templates file in their local git
	# repository and create a GitHub pull request with the newly added component templates.

[github-actions]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
11708	10824	92%	89%	🟢

New Files

No new covered files...

Modified Files

No covered modified files...

updated for commit: 2c4184c by action🐍

[github-actions]

Test Results

     4 files  ±0       4 suites  ±0   41m 34s ⏱️ -1s
 3 200 tests +1   3 198 ✅ +1   2 💤 ±0  0 ❌ ±0 
12 592 runs  +4  12 572 ✅ +4  20 💤 ±0  0 ❌ ±0 

Results for commit 147d431. ± Comparison against base commit 59eb235.