Allow direct String fields to match the empty string

Empty is not the same as missing, and the empty string
crops up a lot in upnp/dlna.
This commit is contained in:
Wez Furlong 2024-06-02 06:09:42 -07:00 committed by Dirkjan Ochtman
parent dfc5894edf
commit a1610f689f
3 changed files with 103 additions and 9 deletions

View File

@ -234,6 +234,7 @@ fn deserialize_struct(
let mut declare_values = TokenStream::new();
let mut return_val = TokenStream::new();
let mut direct = TokenStream::new();
let mut after_loop = TokenStream::new();
let mut borrowed = BTreeSet::new();
for (index, field) in fields.named.iter().enumerate() {
@ -263,6 +264,7 @@ fn deserialize_struct(
field_meta,
&input.ident,
&container_meta,
&mut after_loop,
);
if let Err(err) = result {
@ -361,6 +363,7 @@ fn deserialize_struct(
node => return Err(Error::UnexpectedNode(format!("{:?} in {}", node, #ident_str))),
}
}
#after_loop
*into = Some(Self { #return_val });
Ok(())
@ -401,6 +404,7 @@ fn deserialize_inline_struct(
let mut declare_values = TokenStream::new();
let mut return_val = TokenStream::new();
let mut direct = TokenStream::new();
let mut after_loop = TokenStream::new();
let mut borrowed = BTreeSet::new();
let mut matches = TokenStream::new();
@ -433,6 +437,7 @@ fn deserialize_inline_struct(
field_meta,
&input.ident,
&meta,
&mut after_loop,
);
let data = match result {
@ -548,6 +553,7 @@ fn named_field<'a>(
mut field_meta: FieldMeta,
type_name: &Ident,
container_meta: &ContainerMeta,
after_loop: &mut TokenStream,
) -> Result<FieldData<'a>, syn::Error> {
let field_name = field.ident.as_ref().unwrap();
let field_tag = field_meta.tag;
@ -598,6 +604,15 @@ fn named_field<'a>(
let mut #val_name = <#no_lifetime_type as FromXml>::Accumulator::default();
));
if field_meta.direct {
declare_values.extend(quote!(
// We will synthesize an empty text node when processing a direct
// element. Without this, we can miscategorize an empty tag as
// a missing tag
let mut seen_direct = false;
));
}
let deserialize_with = field_meta
.deserialize_with
.map(|with| {
@ -630,10 +645,21 @@ fn named_field<'a>(
} else if field_meta.direct {
direct.extend(quote!(
Node::Text(text) => {
seen_direct = true;
let mut nested = deserializer.for_node(Node::Text(text));
<#no_lifetime_type>::deserialize(&mut #val_name, #field_str, &mut nested)?;
}
));
// We can only enter this FromXml impl if the caller found the opening
// tag, so if we don't see the text node before the closing tag that is
// implied by terminating the loop, we need to populate the
// direct field with the implied empty text node.
after_loop.extend(quote!(
if !seen_direct {
let mut nested = deserializer.for_node(Node::Text("".into()));
<#no_lifetime_type>::deserialize(&mut #val_name, #field_str, &mut nested)?;
}
));
} else {
tokens.r#match.extend(quote!(
__Elements::#enum_name => match <#no_lifetime_type as FromXml>::KIND {

View File

@ -270,10 +270,10 @@ impl<'xml> FromXml<'xml> for String {
return Err(Error::DuplicateValue(field));
}
match deserializer.take_str()? {
Some(value) => *into = Some(value.into_owned()),
None => return Ok(()),
}
*into = Some(match deserializer.take_str()? {
Some(value) => value.into_owned(),
None => String::new(),
});
Ok(())
}
@ -300,12 +300,11 @@ impl<'xml, 'a> FromXml<'xml> for Cow<'a, str> {
return Err(Error::DuplicateValue(field));
}
let value = match deserializer.take_str()? {
Some(value) => value,
None => return Ok(()),
};
into.inner = Some(match deserializer.take_str()? {
Some(value) => value.into_owned().into(),
None => "".into(),
});
into.inner = Some(value.into_owned().into());
Ok(())
}

View File

@ -1,3 +1,5 @@
use std::borrow::Cow;
use similar_asserts::assert_eq;
use instant_xml::{from_str, Error, FromXml};
@ -33,3 +35,70 @@ fn direct_namespaces() {
Err::<StructDirectNamespace, _>(Error::MissingValue("StructDirectNamespace::flag"))
);
}
#[derive(Debug, Eq, PartialEq, FromXml)]
struct DirectString {
s: String,
}
#[test]
fn direct_string() {
assert_eq!(
from_str("<DirectString><s>hello</s></DirectString>"),
Ok(DirectString {
s: "hello".to_string()
})
);
}
#[derive(Debug, Eq, PartialEq, FromXml)]
struct DirectStr<'a> {
s: Cow<'a, str>,
}
#[test]
fn direct_empty_str() {
assert_eq!(
from_str("<DirectStr><s></s></DirectStr>"),
Ok(DirectStr { s: "".into() })
);
}
#[test]
fn direct_missing_string() {
assert_eq!(
from_str("<DirectString></DirectString>"),
Err::<DirectString, _>(Error::MissingValue("DirectString::s"))
);
}
#[derive(Debug, PartialEq, FromXml)]
struct ArtUri {
#[xml(direct)]
uri: String,
}
#[derive(Debug, PartialEq, FromXml)]
struct Container {
art: Option<ArtUri>,
}
#[test]
fn container_empty_string() {
assert_eq!(
from_str("<Container><ArtUri></ArtUri></Container>"),
Ok(Container {
art: Some(ArtUri {
uri: "".to_string()
})
})
);
assert_eq!(
from_str("<Container><ArtUri/></Container>"),
Ok(Container {
art: Some(ArtUri {
uri: "".to_string()
})
})
);
}