schemars/schemars_derive/src/metadata.rs

93 lines
3.1 KiB
Rust

use proc_macro2::TokenStream;
use syn::spanned::Spanned;
#[derive(Debug, Clone)]
pub struct SchemaMetadata<'a> {
pub title: Option<&'a str>,
pub description: Option<&'a str>,
pub deprecated: bool,
pub read_only: bool,
pub write_only: bool,
pub examples: &'a [syn::Path],
pub default: Option<TokenStream>,
pub extensions: &'a [(String, TokenStream)],
pub transforms: &'a [syn::Expr],
}
impl<'a> SchemaMetadata<'a> {
pub fn apply_to_schema(&self, schema_expr: &mut TokenStream) {
let setters = self.make_setters();
if !setters.is_empty() || !self.transforms.is_empty() {
let apply_transforms = self.transforms.iter().map(|t| {
quote_spanned! {t.span()=>
schemars::transform::Transform::transform(&mut #t, &mut schema);
}
});
*schema_expr = quote! {{
let mut schema = #schema_expr;
#(#setters)*
#(#apply_transforms)*
schema
}}
}
}
fn make_setters(&self) -> Vec<TokenStream> {
let mut setters = Vec::<TokenStream>::new();
if let Some(title) = &self.title {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "title", #title);
});
}
if let Some(description) = &self.description {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "description", #description);
});
}
if self.deprecated {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "deprecated", true);
});
}
if self.read_only {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "readOnly", true);
});
}
if self.write_only {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "writeOnly", true);
});
}
if !self.examples.is_empty() {
let examples = self.examples.iter().map(|eg| {
quote! {
schemars::_serde_json::value::to_value(#eg())
}
});
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, "examples", schemars::_serde_json::Value::Array([#(#examples),*].into_iter().flatten().collect()));
});
}
if let Some(default) = &self.default {
setters.push(quote! {
if let Some(default) = #default.and_then(|d| schemars::_schemars_maybe_to_value!(d)) {
schemars::_private::insert_metadata_property(&mut schema, "default", default);
}
});
}
for (k, v) in self.extensions {
setters.push(quote! {
schemars::_private::insert_metadata_property(&mut schema, #k, schemars::_serde_json::json!(#v));
});
}
setters
}
}