refactor(error): improve error messages and file handling

[simonsan]

• Create parent directory if it does not exist before opening the file for writing.

Fixes rustic-rs/rustic#1315
Fixes #310

[simonsan]

I kept:

        for i in 0u8..=255 {
            let filename = self.path.join("data").join(hex::encode([i]));
            fs::create_dir_all(&filename).map_err(|err| {
                LocalBackendErrorKind::DirectoryCreationFailed {
                    path: filename.clone(),
                    source: err,
                }
            })?;
        }

as that impacts compatibility with restic, and a repository without that, wouldn't be able to be read by it. Hence, I thought, we keep that, but we make sure, that also without these directories (in case someone deletes them), we are able to create and write to these directories. Not sure, how else we could handle that.

[aawsome]

Good catch!
I have just found a small thing I would change in this PR...

[codecov]

Codecov Report

Attention: Patch coverage is 40.00000% with 3 lines in your changes missing coverage. Please review.

Please upload report for BASE (main@171e2aa). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
crates/core/src/commands/check.rs	40.0%	3 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
crates/backend/src/local.rs	0.0% <ø> (ø)
crates/core/src/commands/check.rs	65.4% <40.0%> (ø)

[nardoor]

Hello,

Looks good to me!
Just one question about an error log.

[nardoor]

Question: should this error log be different from the one line 318?