Improve and fix issue in audioconv module

[mitsuki31]

Overview

This pull request addresses several issues and enhancements within the audioconv module. The focus is on improving the reliability of the ffmpeg binary check, ensuring consistent error logging even when the quiet option is enabled, and enhancing the JSDoc documentation for better clarity and maintainability.

Changes Made

Fixes

Improvement to ffmpeg Binary Check and Error Handling

• Removed the use of the promisified exec call to check the ffmpeg version, replacing it with the more reliable spawnSync approach, which prevents asynchronous issues and race conditions.
• Refined the environment variable check for FFMPEG_PATH, adding checks to ensure it is neither null nor undefined before proceeding with the binary check.
• Enhanced the splitOptions function to properly handle options that do not have associated values, ensuring that they are not accidentally concatenated with the next option in the list.
• Streamlined the error handling process during the ffmpeg check, making the logging process clearer and more consistent.

Ensuring Error Logging Works with quiet Option Enabled

• Refactored the writeErrorLog function to return a promise, improving the handling of errors during the log-writing process.
• Updated the error handling within the convertAudio function to ensure that error logs are still written even when the quiet option is enabled, improving reliability in quiet modes.
• Refined the logic for log and console error outputs, making them conditional based on the quiet option to provide better control over the reporting process.
• Added more robust handling for the log stream, ensuring that the promise resolves on finish and properly rejects on error, enhancing the reliability of the logging process.

Documentation Updates

Enhancements to JSDoc Documentation and Type Definitions

• Added default values to the inputOptions and outputOptions fields within the ConvertAudioOptions typedef, improving the clarity of the optional parameters and their usage.
• Introduced a new FFmpegInfo typedef to document the progress data emitted by FFmpeg during the conversion process, aiding in better understanding and usage of the progress event.
• Expanded the JSDoc comments for the writeErrorLog function, providing detailed documentation on the format of error logs, and specifying that the function now returns a Promise.
• Updated the resolveOptions function’s JSDoc to include a module reference, improving the overall documentation structure and accessibility.
• Enhanced the documentation for createConversionProgress, detailing the function’s parameters and return values, and ensuring that it is correctly documented for future use.
• Marked the defaultOptions object as readonly in the documentation, clearly defining its role in the conversion process and preventing unintended modifications.

Fixed Issue

Example Issue with splitOptions Before Fix

Before the fix, when an option was provided without a corresponding value, it could get concatenated with the next option, leading to incorrect behavior:

const outputOptions = '-f -acodec libmp3lame -ar 44100';
splitOptions(options);

Expected output:

['-f', '-acodec libmp3lame', '-ar 44100']

Actual output before fix:

['-f -acodec', '-acodec libmp3lame', '-ar 44100']

In this case, -f and -acodec get concatenated, leading to an invalid option.

---

Example Corrected Behavior After Fix

After the fix, splitOptions correctly handles options without values, ensuring they remain separate:

const options = '-f -acodec libmp3lame -ar 44100';
splitOptions(options);

Correct output:

['-f', '-acodec libmp3lame', '-ar 44100']

Now, each option is treated as an individual entry, preserving the integrity of the options passed to FFmpeg.

---

Impact

• These changes improve the robustness and maintainability of the audioconv module, addressing key issues that could lead to unreliable behavior in production environments.
• The enhanced documentation provides a solid foundation for future development and usage of the module, making it easier for others to contribute and maintain.

[codecov]

Codecov Report

Attention: Patch coverage is 16.66667% with 25 lines in your changes missing coverage. Please review.

Project coverage is 42.05%. Comparing base (3a66580) to head (91365f8).
Report is 4 commits behind head on master.

Files	Patch %	Lines
lib/audioconv.js	16.66%	25 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #40      +/-   ##
==========================================
- Coverage   42.75%   42.05%   -0.70%     
==========================================
  Files           7        7              
  Lines         407      409       +2     
==========================================
- Hits          174      172       -2     
- Misses        233      237       +4     

Flag	Coverage Δ
Ubuntu	42.05% <16.66%> (-0.70%)	⬇️
Windows	42.05% <16.66%> (-0.70%)	⬇️
macOS	42.05% <16.66%> (-0.70%)	⬇️
unittests	42.05% <16.66%> (-0.70%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.