Autoformat removes new-line before EOF

[kaysievers]

Describe the problem

The autoformat feature removes the last line's new-line, disturbs all sorts of diff / git tools.

Quoting the C++ standard: A source file that is not empty and that does not end in a new-line character, or that ends in a splice, shall be processed as if an additional new-line character were appended to the file.

Could this be changed to leave the new-line in place, or maybe even add one if it is missing?

Thanks!

Example:

To reproduce

Press CMD-T and save. Look at the last character in the sketch file.

Expected behavior

Leave the new-line before EOF in place.

Arduino IDE version

2.0-nightly-202209

Operating system

macOS

Operating system version

12.6

Additional context

No response

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest nightly build
• My report contains all necessary details

[per1234]

Thanks for reporting this @kaysievers. The ClangFormat formatting tool used by Arduino IDE 2.x does not remove the newline, so it is a bug in the Arduino IDE code itself.

maybe even add one if it is missing?

Surprisingly for such a comprehensive tool, ClangFormat doesn't provide this capability:

llvm/llvm-project#38042

Also surprising is that the Eclipse Theia IDE framework Arduino IDE 2.x is built on doesn't provide an setting for this, as VS Code does with its files.insertFinalNewline.

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I think there is a way for the user to set up Arduino IDE 2.x do this, which would even counteract the formatter's current removal of the newline. However, discussion of that is not really appropriate for the issue tracker. I'm certain that if you post over on the Arduino forum someone will provide you with instructions:

https://forum.arduino.cc/c/software/arduino-ide-2-0/93