Python video generator silently skips missing keyboard sound files

Issue

The video generation system produced videos with missing keyboard sounds for specific characters when their sound files were unavailable. The system silently fell back to a non-existent generic.wav file, resulting in empty audio tracks for characters like f.wav. This issue was not detected until users reviewed the final videos, with no errors or warnings during generation.

Culprit

The root cause was a silent fallback mechanism in the system’s code renderer that substituted missing sound files with a hardcoded path to generic.wav without:

1. Verifying the existence of the fallback file.
2. Logging any warnings about missing files.
3. Providing feedback on which characters lacked sound mappings.

Additionally, unmapped characters defaulted to generic.wav without validation, contributing to the silent failures.

Solution

To address the issue, explicit failure handling was implemented to:

1. Fail Immediately on Missing Files: Replace silent fallbacks with explicit FileNotFoundError exceptions that include detailed error messages, such as missing file paths, character details, and expected filenames.
2. Explicit Character Mapping Validation: Introduce ValueError for unmapped characters, providing actionable guidance on how to add new character mappings.

These changes ensure that missing files and unmapped characters are immediately detected during generation, improving debugging and maintenance by providing clear error messages and instructions for resolving issues.