From 852e548e19c7d44de469a37688d5e233d5b475bd Mon Sep 17 00:00:00 2001
From: David Pedersen <david.pdrsn@gmail.com>
Date: Sun, 8 May 2022 20:04:56 +0200
Subject: [PATCH] Support `#[derive(FromRequest)]` on enums (#1009)
* Support `#[from_request(via(...))]` on enums
* Check `#[from_request]` on variants
* check for non enum/struct and clean up
* changelog
* changelog
* remove needless feature
* changelog ref
---
axum-macros/CHANGELOG.md | 2 +
axum-macros/src/from_request.rs | 146 +++++++++++++++---
axum-macros/src/from_request/attr.rs | 6 +-
.../enum_from_request_ident_in_variant.rs | 12 ++
.../enum_from_request_ident_in_variant.stderr | 5 +
.../fail/enum_from_request_on_variant.rs | 10 ++
.../fail/enum_from_request_on_variant.stderr | 5 +
.../tests/from_request/fail/enum_no_via.rs | 6 +
.../from_request/fail/enum_no_via.stderr | 7 +
.../fail/enum_rejection_derive.rs | 7 +
.../fail/enum_rejection_derive.stderr | 5 +
.../from_request/fail/not_enum_or_struct.rs | 6 +
.../fail/not_enum_or_struct.stderr | 11 ++
.../tests/from_request/pass/enum_via.rs | 12 ++
14 files changed, 215 insertions(+), 25 deletions(-)
create mode 100644 axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.rs
create mode 100644 axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.stderr
create mode 100644 axum-macros/tests/from_request/fail/enum_from_request_on_variant.rs
create mode 100644 axum-macros/tests/from_request/fail/enum_from_request_on_variant.stderr
create mode 100644 axum-macros/tests/from_request/fail/enum_no_via.rs
create mode 100644 axum-macros/tests/from_request/fail/enum_no_via.stderr
create mode 100644 axum-macros/tests/from_request/fail/enum_rejection_derive.rs
create mode 100644 axum-macros/tests/from_request/fail/enum_rejection_derive.stderr
create mode 100644 axum-macros/tests/from_request/fail/not_enum_or_struct.rs
create mode 100644 axum-macros/tests/from_request/fail/not_enum_or_struct.stderr
create mode 100644 axum-macros/tests/from_request/pass/enum_via.rs
diff --git a/axum-macros/CHANGELOG.md b/axum-macros/CHANGELOG.md
index 6a1377d0..a983d92b 100644
--- a/axum-macros/CHANGELOG.md
+++ b/axum-macros/CHANGELOG.md
@@ -9,9 +9,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
- **fixed:** `Option` and `Result` are now supported in typed path route handler parameters ([#1001])
- **fixed:** Support wildcards in typed paths ([#1003])
+- **added:** Support `#[derive(FromRequest)]` on enums using `#[from_request(via(OtherExtractor))]` ([#1009])
[#1001]: https://github.com/tokio-rs/axum/pull/1001
[#1003]: https://github.com/tokio-rs/axum/pull/1003
+[#1009]: https://github.com/tokio-rs/axum/pull/1009
# 0.2.0 (31. March, 2022)
diff --git a/axum-macros/src/from_request.rs b/axum-macros/src/from_request.rs
index 901b2688..76634ee9 100644
--- a/axum-macros/src/from_request.rs
+++ b/axum-macros/src/from_request.rs
@@ -3,24 +3,77 @@ use self::attr::{
RejectionDeriveOptOuts,
};
use heck::ToUpperCamelCase;
-use proc_macro2::TokenStream;
+use proc_macro2::{Span, TokenStream};
use quote::{format_ident, quote, quote_spanned};
use syn::{punctuated::Punctuated, spanned::Spanned, Token};
mod attr;
-const GENERICS_ERROR: &str = "`#[derive(FromRequest)] doesn't support generics";
+pub(crate) fn expand(item: syn::Item) -> syn::Result<TokenStream> {
+ match item {
+ syn::Item::Struct(item) => {
+ let syn::ItemStruct {
+ attrs,
+ ident,
+ generics,
+ fields,
+ semi_token: _,
+ vis,
+ struct_token: _,
+ } = item;
-pub(crate) fn expand(item: syn::ItemStruct) -> syn::Result<TokenStream> {
- let syn::ItemStruct {
- attrs,
- ident,
- generics,
- fields,
- semi_token: _,
- vis,
- struct_token: _,
- } = item;
+ error_on_generics(generics)?;
+
+ match parse_container_attrs(&attrs)? {
+ FromRequestContainerAttr::Via(path) => {
+ impl_struct_by_extracting_all_at_once(ident, fields, path)
+ }
+ FromRequestContainerAttr::RejectionDerive(_, opt_outs) => {
+ impl_struct_by_extracting_each_field(ident, fields, vis, opt_outs)
+ }
+ FromRequestContainerAttr::None => impl_struct_by_extracting_each_field(
+ ident,
+ fields,
+ vis,
+ RejectionDeriveOptOuts::default(),
+ ),
+ }
+ }
+ syn::Item::Enum(item) => {
+ let syn::ItemEnum {
+ attrs,
+ vis: _,
+ enum_token: _,
+ ident,
+ generics,
+ brace_token: _,
+ variants,
+ } = item;
+
+ error_on_generics(generics)?;
+
+ match parse_container_attrs(&attrs)? {
+ FromRequestContainerAttr::Via(path) => {
+ impl_enum_by_extracting_all_at_once(ident, variants, path)
+ }
+ FromRequestContainerAttr::RejectionDerive(rejection_derive, _) => {
+ Err(syn::Error::new_spanned(
+ rejection_derive,
+ "cannot use `rejection_derive` on enums",
+ ))
+ }
+ FromRequestContainerAttr::None => Err(syn::Error::new(
+ Span::call_site(),
+ "missing `#[from_request(via(...))]`",
+ )),
+ }
+ }
+ _ => Err(syn::Error::new_spanned(item, "expected `struct` or `enum`")),
+ }
+}
+
+fn error_on_generics(generics: syn::Generics) -> syn::Result<()> {
+ const GENERICS_ERROR: &str = "`#[derive(FromRequest)] doesn't support generics";
if !generics.params.is_empty() {
return Err(syn::Error::new_spanned(generics, GENERICS_ERROR));
@@ -30,18 +83,10 @@ pub(crate) fn expand(item: syn::ItemStruct) -> syn::Result<TokenStream> {
return Err(syn::Error::new_spanned(where_clause, GENERICS_ERROR));
}
- match parse_container_attrs(&attrs)? {
- FromRequestContainerAttr::Via(path) => impl_by_extracting_all_at_once(ident, fields, path),
- FromRequestContainerAttr::RejectionDerive(opt_outs) => {
- impl_by_extracting_each_field(ident, fields, vis, opt_outs)
- }
- FromRequestContainerAttr::None => {
- impl_by_extracting_each_field(ident, fields, vis, RejectionDeriveOptOuts::default())
- }
- }
+ Ok(())
}
-fn impl_by_extracting_each_field(
+fn impl_struct_by_extracting_each_field(
ident: syn::Ident,
fields: syn::Fields,
vis: syn::Visibility,
@@ -413,7 +458,7 @@ fn rejection_variant_name(field: &syn::Field) -> syn::Result<syn::Ident> {
}
}
-fn impl_by_extracting_all_at_once(
+fn impl_struct_by_extracting_all_at_once(
ident: syn::Ident,
fields: syn::Fields,
path: syn::Path,
@@ -459,6 +504,61 @@ fn impl_by_extracting_all_at_once(
})
}
+fn impl_enum_by_extracting_all_at_once(
+ ident: syn::Ident,
+ variants: Punctuated<syn::Variant, Token![,]>,
+ path: syn::Path,
+) -> syn::Result<TokenStream> {
+ for variant in variants {
+ let FromRequestFieldAttr { via } = parse_field_attrs(&variant.attrs)?;
+ if let Some((via, _)) = via {
+ return Err(syn::Error::new_spanned(
+ via,
+ "`#[from_request(via(...))]` cannot be used on variants",
+ ));
+ }
+
+ let fields = match variant.fields {
+ syn::Fields::Named(fields) => fields.named.into_iter(),
+ syn::Fields::Unnamed(fields) => fields.unnamed.into_iter(),
+ syn::Fields::Unit => Punctuated::<_, Token![,]>::new().into_iter(),
+ };
+
+ for field in fields {
+ let FromRequestFieldAttr { via } = parse_field_attrs(&field.attrs)?;
+ if let Some((via, _)) = via {
+ return Err(syn::Error::new_spanned(
+ via,
+ "`#[from_request(via(...))]` cannot be used inside variants",
+ ));
+ }
+ }
+ }
+
+ let path_span = path.span();
+
+ Ok(quote_spanned! {path_span=>
+ #[::axum::async_trait]
+ #[automatically_derived]
+ impl<B> ::axum::extract::FromRequest<B> for #ident
+ where
+ B: ::axum::body::HttpBody + ::std::marker::Send + 'static,
+ B::Data: ::std::marker::Send,
+ B::Error: ::std::convert::Into<::axum::BoxError>,
+ {
+ type Rejection = <#path<Self> as ::axum::extract::FromRequest<B>>::Rejection;
+
+ async fn from_request(
+ req: &mut ::axum::extract::RequestParts<B>,
+ ) -> ::std::result::Result<Self, Self::Rejection> {
+ ::axum::extract::FromRequest::<B>::from_request(req)
+ .await
+ .map(|#path(inner)| inner)
+ }
+ }
+ })
+}
+
#[test]
fn ui() {
#[rustversion::stable]
diff --git a/axum-macros/src/from_request/attr.rs b/axum-macros/src/from_request/attr.rs
index 25c989a0..657c7bd6 100644
--- a/axum-macros/src/from_request/attr.rs
+++ b/axum-macros/src/from_request/attr.rs
@@ -12,7 +12,7 @@ pub(crate) struct FromRequestFieldAttr {
pub(crate) enum FromRequestContainerAttr {
Via(syn::Path),
- RejectionDerive(RejectionDeriveOptOuts),
+ RejectionDerive(kw::rejection_derive, RejectionDeriveOptOuts),
None,
}
@@ -91,7 +91,9 @@ pub(crate) fn parse_container_attrs(
}
}
(Some((_, _, path)), None) => Ok(FromRequestContainerAttr::Via(path)),
- (None, Some((_, _, opt_outs))) => Ok(FromRequestContainerAttr::RejectionDerive(opt_outs)),
+ (None, Some((_, rejection_derive, opt_outs))) => Ok(
+ FromRequestContainerAttr::RejectionDerive(rejection_derive, opt_outs),
+ ),
(None, None) => Ok(FromRequestContainerAttr::None),
}
}
diff --git a/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.rs b/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.rs
new file mode 100644
index 00000000..336850e5
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.rs
@@ -0,0 +1,12 @@
+use axum_macros::FromRequest;
+
+#[derive(FromRequest, Clone)]
+#[from_request(via(axum::Extension))]
+enum Extractor {
+ Foo {
+ #[from_request(via(axum::Extension))]
+ foo: (),
+ }
+}
+
+fn main() {}
diff --git a/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.stderr b/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.stderr
new file mode 100644
index 00000000..f998004a
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_from_request_ident_in_variant.stderr
@@ -0,0 +1,5 @@
+error: `#[from_request(via(...))]` cannot be used inside variants
+ --> tests/from_request/fail/enum_from_request_ident_in_variant.rs:7:24
+ |
+7 | #[from_request(via(axum::Extension))]
+ | ^^^
diff --git a/axum-macros/tests/from_request/fail/enum_from_request_on_variant.rs b/axum-macros/tests/from_request/fail/enum_from_request_on_variant.rs
new file mode 100644
index 00000000..6b825077
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_from_request_on_variant.rs
@@ -0,0 +1,10 @@
+use axum_macros::FromRequest;
+
+#[derive(FromRequest, Clone)]
+#[from_request(via(axum::Extension))]
+enum Extractor {
+ #[from_request(via(axum::Extension))]
+ Foo,
+}
+
+fn main() {}
diff --git a/axum-macros/tests/from_request/fail/enum_from_request_on_variant.stderr b/axum-macros/tests/from_request/fail/enum_from_request_on_variant.stderr
new file mode 100644
index 00000000..9818da51
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_from_request_on_variant.stderr
@@ -0,0 +1,5 @@
+error: `#[from_request(via(...))]` cannot be used on variants
+ --> tests/from_request/fail/enum_from_request_on_variant.rs:6:20
+ |
+6 | #[from_request(via(axum::Extension))]
+ | ^^^
diff --git a/axum-macros/tests/from_request/fail/enum_no_via.rs b/axum-macros/tests/from_request/fail/enum_no_via.rs
new file mode 100644
index 00000000..f5add219
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_no_via.rs
@@ -0,0 +1,6 @@
+use axum_macros::FromRequest;
+
+#[derive(FromRequest, Clone)]
+enum Extractor {}
+
+fn main() {}
diff --git a/axum-macros/tests/from_request/fail/enum_no_via.stderr b/axum-macros/tests/from_request/fail/enum_no_via.stderr
new file mode 100644
index 00000000..e1f86d53
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_no_via.stderr
@@ -0,0 +1,7 @@
+error: missing `#[from_request(via(...))]`
+ --> tests/from_request/fail/enum_no_via.rs:3:10
+ |
+3 | #[derive(FromRequest, Clone)]
+ | ^^^^^^^^^^^
+ |
+ = note: this error originates in the derive macro `FromRequest` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/axum-macros/tests/from_request/fail/enum_rejection_derive.rs b/axum-macros/tests/from_request/fail/enum_rejection_derive.rs
new file mode 100644
index 00000000..f343d544
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_rejection_derive.rs
@@ -0,0 +1,7 @@
+use axum_macros::FromRequest;
+
+#[derive(FromRequest, Clone)]
+#[from_request(rejection_derive(!Error))]
+enum Extractor {}
+
+fn main() {}
diff --git a/axum-macros/tests/from_request/fail/enum_rejection_derive.stderr b/axum-macros/tests/from_request/fail/enum_rejection_derive.stderr
new file mode 100644
index 00000000..1e721d76
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/enum_rejection_derive.stderr
@@ -0,0 +1,5 @@
+error: cannot use `rejection_derive` on enums
+ --> tests/from_request/fail/enum_rejection_derive.rs:4:16
+ |
+4 | #[from_request(rejection_derive(!Error))]
+ | ^^^^^^^^^^^^^^^^
diff --git a/axum-macros/tests/from_request/fail/not_enum_or_struct.rs b/axum-macros/tests/from_request/fail/not_enum_or_struct.rs
new file mode 100644
index 00000000..989ca26d
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/not_enum_or_struct.rs
@@ -0,0 +1,6 @@
+use axum_macros::FromRequest;
+
+#[derive(FromRequest)]
+union Extractor {}
+
+fn main() {}
diff --git a/axum-macros/tests/from_request/fail/not_enum_or_struct.stderr b/axum-macros/tests/from_request/fail/not_enum_or_struct.stderr
new file mode 100644
index 00000000..6a755643
--- /dev/null
+++ b/axum-macros/tests/from_request/fail/not_enum_or_struct.stderr
@@ -0,0 +1,11 @@
+error: expected `struct` or `enum`
+ --> tests/from_request/fail/not_enum_or_struct.rs:4:1
+ |
+4 | union Extractor {}
+ | ^^^^^^^^^^^^^^^^^^
+
+error: unions cannot have zero fields
+ --> tests/from_request/fail/not_enum_or_struct.rs:4:1
+ |
+4 | union Extractor {}
+ | ^^^^^^^^^^^^^^^^^^
diff --git a/axum-macros/tests/from_request/pass/enum_via.rs b/axum-macros/tests/from_request/pass/enum_via.rs
new file mode 100644
index 00000000..d6ba90e2
--- /dev/null
+++ b/axum-macros/tests/from_request/pass/enum_via.rs
@@ -0,0 +1,12 @@
+use axum::{body::Body, routing::get, Extension, Router};
+use axum_macros::FromRequest;
+
+#[derive(FromRequest, Clone)]
+#[from_request(via(Extension))]
+enum Extractor {}
+
+async fn foo(_: Extractor) {}
+
+fn main() {
+ Router::<Body>::new().route("/", get(foo));
+}