Add GitHub action to automatically add EOL @ EOF

[JLLeitschuh]

According to how the posix standard defines a line

3.206 Line
A sequence of zero or more non- characters plus a terminating character.

Thus, many of the files in this repository that don't contain a newline at the end of the file contain a file where the last line isn't, according to the spec actually a line.

This GitHub action resolves this issue by automatically adding a End of Line (EOL) @ End of File (EOF).

[hmakholm]

I wonder if fixing that automatically is desirable in the first place. Among the things this repo contains are test cases for the language extractors. It feels plausible that we'd want some of the test inputs to lack terminating newlines, such that parsing and location reporting in those cases can be exercised.

[JLLeitschuh]

You can specify an list of files to ignore in the config.

[esbena]

Drive-by comments: this 2.5 year old PR has grown stale wrt. best Action practices.

[JLLeitschuh]

@esbena PR has been updated to address concerns

[aibaars]

One thing to note is that the POSIX is about portability across operating systems. It has nothing to do with programming language specifications. The questions of "what is a line" and even "what is a character" vary between programming languages. For example https://262.ecma-international.org/8.0/#table-33 . I'm all in favour of automatically formatting source files, and quite like having newline characters at the end of files. However, I'm not sure we want to enforce this.

Another things to note:

This action will automatically fix files without a final new line in pull requests.
Only works for UTF-8 files.

I think most of our files are UTF-8, so this shouldn't be too much of an issue.

[JLLeitschuh]

The other thing that I notice is that, many IDEs or anyone that has an .editorconfig file in their root directory ends up adding the newline to files they modify when they create a PR changing a file. This means that the final newline getting added ends up being kinda random, and only happens to certain files modified by certain people.

By enforcing this org-wide will mean that it's finally consistent