Read #[validate(...)] attributes

This commit is contained in:
Graham Esau 2021-03-29 16:38:55 +01:00
parent dada8582ee
commit 6ab567f3a5
13 changed files with 532 additions and 33 deletions

View file

@ -0,0 +1,308 @@
use super::parse_lit_str;
use proc_macro2::TokenStream;
use syn::ExprLit;
use syn::NestedMeta;
use syn::{Expr, Lit, Meta, MetaNameValue, Path};
#[derive(Debug, Default)]
pub struct ValidationAttrs {
pub length_min: Option<Expr>,
pub length_max: Option<Expr>,
pub length_equal: Option<Expr>,
pub range_min: Option<Expr>,
pub range_max: Option<Expr>,
pub regex: Option<Path>,
pub contains: Option<String>,
pub required: bool,
pub format: Option<&'static str>,
}
impl ValidationAttrs {
pub fn new(attrs: &[syn::Attribute]) -> Self {
// TODO allow setting "validate" attributes through #[schemars(...)]
ValidationAttrs::default().populate(attrs)
}
fn populate(mut self, attrs: &[syn::Attribute]) -> Self {
// TODO don't silently ignore unparseable attributes
for meta_item in attrs
.iter()
.flat_map(|attr| get_meta_items(attr, "validate"))
.flatten()
{
match &meta_item {
NestedMeta::Meta(Meta::List(meta_list)) if meta_list.path.is_ident("length") => {
for nested in meta_list.nested.iter() {
match nested {
NestedMeta::Meta(Meta::NameValue(nv)) if nv.path.is_ident("min") => {
self.length_min = str_or_num_to_expr(&nv.lit);
}
NestedMeta::Meta(Meta::NameValue(nv)) if nv.path.is_ident("max") => {
self.length_max = str_or_num_to_expr(&nv.lit);
}
NestedMeta::Meta(Meta::NameValue(nv)) if nv.path.is_ident("equal") => {
self.length_equal = str_or_num_to_expr(&nv.lit);
}
_ => {}
}
}
}
NestedMeta::Meta(Meta::List(meta_list)) if meta_list.path.is_ident("range") => {
for nested in meta_list.nested.iter() {
match nested {
NestedMeta::Meta(Meta::NameValue(nv)) if nv.path.is_ident("min") => {
self.range_min = str_or_num_to_expr(&nv.lit);
}
NestedMeta::Meta(Meta::NameValue(nv)) if nv.path.is_ident("max") => {
self.range_max = str_or_num_to_expr(&nv.lit);
}
_ => {}
}
}
}
NestedMeta::Meta(m)
if m.path().is_ident("required") || m.path().is_ident("required_nested") =>
{
self.required = true;
}
NestedMeta::Meta(m) if m.path().is_ident("email") => {
self.format = Some("email");
}
NestedMeta::Meta(m) if m.path().is_ident("url") => {
self.format = Some("uri");
}
NestedMeta::Meta(m) if m.path().is_ident("phone") => {
self.format = Some("phone");
}
NestedMeta::Meta(Meta::NameValue(MetaNameValue {
path,
lit: Lit::Str(regex),
..
})) if path.is_ident("regex") => self.regex = parse_lit_str(regex).ok(),
NestedMeta::Meta(Meta::List(meta_list)) if meta_list.path.is_ident("regex") => {
self.regex = meta_list.nested.iter().find_map(|x| match x {
NestedMeta::Meta(Meta::NameValue(MetaNameValue {
path,
lit: Lit::Str(regex),
..
})) if path.is_ident("path") => parse_lit_str(regex).ok(),
_ => None,
});
}
NestedMeta::Meta(Meta::NameValue(MetaNameValue {
path,
lit: Lit::Str(contains),
..
})) if path.is_ident("contains") => self.contains = Some(contains.value()),
NestedMeta::Meta(Meta::List(meta_list)) if meta_list.path.is_ident("contains") => {
self.contains = meta_list.nested.iter().find_map(|x| match x {
NestedMeta::Meta(Meta::NameValue(MetaNameValue {
path,
lit: Lit::Str(contains),
..
})) if path.is_ident("pattern") => Some(contains.value()),
_ => None,
});
}
_ => {}
}
}
self
}
pub fn validation_statements(&self, field_name: &str) -> TokenStream {
// Assume that the result will be interpolated in a context with the local variable
// `schema_object` - the SchemaObject for the struct that contains this field.
let mut statements = Vec::new();
if self.required {
statements.push(quote! {
schema_object.object().required.insert(#field_name.to_owned());
});
}
let mut array_validation = Vec::new();
let mut number_validation = Vec::new();
let mut object_validation = Vec::new();
let mut string_validation = Vec::new();
if let Some(length_min) = self
.length_min
.as_ref()
.or_else(|| self.length_equal.as_ref())
{
string_validation.push(quote! {
validation.min_length = Some(#length_min as u32);
});
array_validation.push(quote! {
validation.min_items = Some(#length_min as u32);
});
}
if let Some(length_max) = self
.length_max
.as_ref()
.or_else(|| self.length_equal.as_ref())
{
string_validation.push(quote! {
validation.max_length = Some(#length_max as u32);
});
array_validation.push(quote! {
validation.max_items = Some(#length_max as u32);
});
}
if let Some(range_min) = &self.range_min {
number_validation.push(quote! {
validation.minimum = Some(#range_min as f64);
});
}
if let Some(range_max) = &self.range_max {
number_validation.push(quote! {
validation.maximum = Some(#range_max as f64);
});
}
if let Some(regex) = &self.regex {
string_validation.push(quote! {
validation.pattern = Some(#regex.to_string());
});
}
if let Some(contains) = &self.contains {
object_validation.push(quote! {
validation.required.insert(#contains.to_string());
});
if self.regex.is_none() {
let pattern = crate::regex_syntax::escape(contains);
string_validation.push(quote! {
validation.pattern = Some(#pattern.to_string());
});
}
}
let format = self.format.as_ref().map(|f| {
quote! {
prop_schema_object.format = Some(#f.to_string());
}
});
let array_validation = wrap_array_validation(array_validation);
let number_validation = wrap_number_validation(number_validation);
let object_validation = wrap_object_validation(object_validation);
let string_validation = wrap_string_validation(string_validation);
if array_validation.is_some()
|| number_validation.is_some()
|| object_validation.is_some()
|| string_validation.is_some()
|| format.is_some()
{
statements.push(quote! {
if let Some(schemars::schema::Schema::Object(prop_schema_object)) = schema_object
.object
.as_mut()
.and_then(|o| o.properties.get_mut(#field_name))
{
#array_validation
#number_validation
#object_validation
#string_validation
#format
}
});
}
statements.into_iter().collect()
}
}
fn wrap_array_validation(v: Vec<TokenStream>) -> Option<TokenStream> {
if v.is_empty() {
None
} else {
Some(quote! {
if prop_schema_object.has_type(schemars::schema::InstanceType::Array) {
let validation = prop_schema_object.array();
#(#v)*
}
})
}
}
fn wrap_number_validation(v: Vec<TokenStream>) -> Option<TokenStream> {
if v.is_empty() {
None
} else {
Some(quote! {
if prop_schema_object.has_type(schemars::schema::InstanceType::Integer)
|| prop_schema_object.has_type(schemars::schema::InstanceType::Number) {
let validation = prop_schema_object.number();
#(#v)*
}
})
}
}
fn wrap_object_validation(v: Vec<TokenStream>) -> Option<TokenStream> {
if v.is_empty() {
None
} else {
Some(quote! {
if prop_schema_object.has_type(schemars::schema::InstanceType::Object) {
let validation = prop_schema_object.object();
#(#v)*
}
})
}
}
fn wrap_string_validation(v: Vec<TokenStream>) -> Option<TokenStream> {
if v.is_empty() {
None
} else {
Some(quote! {
if prop_schema_object.has_type(schemars::schema::InstanceType::String) {
let validation = prop_schema_object.string();
#(#v)*
}
})
}
}
fn get_meta_items(
attr: &syn::Attribute,
attr_type: &'static str,
) -> Result<Vec<syn::NestedMeta>, ()> {
if !attr.path.is_ident(attr_type) {
return Ok(Vec::new());
}
match attr.parse_meta() {
Ok(Meta::List(meta)) => Ok(meta.nested.into_iter().collect()),
_ => Err(()),
}
}
fn str_or_num_to_expr(lit: &Lit) -> Option<Expr> {
match lit {
Lit::Str(s) => parse_lit_str::<syn::ExprPath>(s).ok().map(Expr::Path),
Lit::Int(_) | Lit::Float(_) => Some(Expr::Lit(ExprLit {
attrs: Vec::new(),
lit: lit.clone(),
})),
_ => None,
}
}