Remove tar combinations from compression format

[SpyrosRoum]

This allows us to remove a lot of duplicate code and make things simpler. It also doesn't remove any functionality as far as I can see.

[marcospb19]

It's been some time since I have been thinking about a rewrite of CompressionFormat, I planned on something like this:

pub struct Extension {
    compression_formats: Vec<CompressionFormat>,
    display_text: String, // or &str or OsStr or OsString, idk
}

This would allow us removing Tgz and Tlzma from that enum too.

So the extension .tgz would be made of:

Extension { compression_formats: vec![Tar, Gz], display_text: "tgz".into() }

Cause the code in this PR will likely break this piece of code:

ouch/src/commands.rs

Line 63 in a02eb45

let extensions_text: String = formats.iter().map(|format| format.to_string()).collect();

In this line, we get all the compression formats and use them to compose this string of extensions, so we can have the flexibility to change archive.gz.xz to archive.tar.gz.xz by just adding that .tar in the middle.

This requires the Display impl:

ouch/src/extension.rs

Lines 28 to 47 in a02eb45

	impl fmt::Display for CompressionFormat {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	write!(
	f,
	"{}",
	match self {
	Gzip => ".gz",
	Bzip => ".bz",
	Zstd => ".zst",
	Lzma => ".lz",
	Tar => ".tar",
	Tgz => ".tgz",
	Tbz => ".tbz",
	Tlzma => ".tlz",
	Tzst => ".tzst",
	Zip => ".zip",
	}
	)
	}
	}

Of Extension to retrieve what was given in the CLI.

For example: If the user typed archive.tgz, and we trigger some error message with this extensions Display stuff, it would print archive.tar.gz instead, which can be confusing.

Ideas:

1. Rework the Extension and CompressionFormat as I told in this comment.
2. Change how we use extensions in error messages, having another system of "parsing the file_name of a filepath".
3. Other?? idk

(See #88 too)

[SpyrosRoum]

Is this about what you were thinking?
It touches a lot of sensitive places so I'd appreciate it if you could take a good look (we should really improve our tests soon).

[figsoda]

or we could just not store the extension strings and get it from the original path every time we want to print an error

[marcospb19]

or we could just not store the extension strings and get it from the original path every time we want to print an error

That's also possible, but in that case we would need come with another system to do the parsing and reformatting again, could happen, but may be harder to implement.

[marcospb19]

Merged with some warnings still, but I can fix those.

Maybe the missing_docs lints is too aggressive, idk.

[marcospb19]

Oops, found one bug:

$ cargo run -q -- c src src.xz
[ERROR] Cannot compress to 'src.xz'.
 - You are trying to compress multiple files.
 - The compression format 'xz' cannot receive multiple files.
 - The only supported formats that archive files into an archive are .tar and .zip.

hint: Try inserting '.tar' or '.zip' before 'xz'.
hint: From: src.xz
hint:  To : src..tarxz

The last line:

hint:  To : src..tarxz

Should be src.tar.xz.

EDIT: is it really a regression tho? Or was my code there always wrong?

[SpyrosRoum]

Well that case used to panic before so overall it's an improvement I'd say haha

[marcospb19]

Bug 2 comments above was fixed by #219 🙂.