The current implementation does not panic on VcardBuilder::build(), so
we unwrap() that directly.
Should be fixed in future versions of either rust-vobject or here, so
that we error appropriately.
Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
In case of auto-generating the file name, we should add an extension.
If we do not auto-generate the file name, we should warn that the
extension for the file is missing.
The complexity of the create() routine justifies the move to another file.
This commit implements the create() functionality which creates a TOML
tempfile which the user should edit and then reads the contents to build
the Vcard object which then gets written to either stdout or the
destination file.
Besides that:
* Move helper function to util module
* Rewrite and fix tests
