Improve 'FromForm' derive error spans.

contrib/codegen/Cargo.toml

@@ -19,7 +19,7 @@ proc-macro = true
 
 [dependencies]
 quote = "1.0"
-devise = { git = "https://github.com/SergioBenitez/Devise.git", rev = "bd221a4" }
+devise = { git = "https://github.com/SergioBenitez/Devise.git", rev = "3ebe83" }
 
 [dev-dependencies]
 rocket = { version = "0.5.0-dev", path = "../../core/lib" }

core/codegen/Cargo.toml

@@ -18,7 +18,7 @@ proc-macro = true
 indexmap = "1.0"
 quote = "1.0"
 rocket_http = { version = "0.5.0-dev", path = "../http/" }
-devise = { git = "https://github.com/SergioBenitez/Devise.git", rev = "bd221a4" }
+devise = { git = "https://github.com/SergioBenitez/Devise.git", rev = "3ebe83" }
 unicode-xid = "0.2"
 glob = "0.3"
 

core/codegen/src/attribute/route/mod.rs

@@ -328,7 +328,7 @@ fn incomplete_route(
 
     let attribute = Attribute {
         method: SpanWrapped {
-            full_span: method_span, span: method_span, value: Method(method)
+            full_span: method_span, key_span: None, span: method_span, value: Method(method)
         },
         uri: method_attribute.uri,
         data: method_attribute.data,

core/codegen/src/derive/form_field.rs

@@ -3,8 +3,8 @@ use devise::{*, ext::{TypeExt, SpanDiagnosticExt}};
 use syn::visit_mut::VisitMut;
 use syn::visit::Visit;
 
-use crate::exports::*;
 use crate::proc_macro2::{Span, TokenStream, TokenTree};
+use crate::syn_ext::IdentExt;
 use crate::name::Name;
 
 pub struct FormField {
@@ -15,7 +15,7 @@ pub struct FormField {
 #[derive(FromMeta)]
 pub struct FieldAttr {
     pub name: Option<FormField>,
-    pub validate: Option<syn::Expr>,
+    pub validate: Option<SpanWrapped<syn::Expr>>,
 }
 
 impl FieldAttr {
@@ -89,6 +89,7 @@ impl FieldExt for Field<'_> {
 
     fn name_view(&self) -> Result<syn::Expr> {
         let field_name = self.field_name()?;
+        define_spanned_export!(self.span() => _form);
         let name_view = quote_spanned! { self.span() =>
             #_form::NameBuf::from((__c.__parent, #field_name))
         };
@@ -201,7 +202,7 @@ pub fn validators<'v>(
     parent: &'v syn::Ident, // field ident (if local) or form ident (if !local)
     local: bool,
 ) -> Result<impl Iterator<Item = syn::Expr> + 'v> {
-    Ok(FieldAttr::from_attrs(FieldAttr::NAME, &field.attrs)?
+    let exprs = FieldAttr::from_attrs(FieldAttr::NAME, &field.attrs)?
         .into_iter()
         .filter_map(|a| a.validate)
         .map(move |expr| {
@@ -219,9 +220,21 @@ pub fn validators<'v>(
         })
         .filter(move |(_, is_local)| *is_local == local)
         .map(move |(mut expr, _)| {
-            let field = field.ident();
-            let mut v = ValidationMutator { parent, local, field, visited: false };
+            let field_span = field.ident().span()
+                .join(field.ty.span())
+                .unwrap_or(field.ty.span());
+
+            let field_ident = field.ident().clone().with_span(field_span);
+            let mut v = ValidationMutator { parent, local, field: &field_ident, visited: false };
             v.visit_expr_mut(&mut expr);
-            expr
-        }))
+
+            let span = expr.key_span.unwrap_or(field_span);
+            define_spanned_export!(span => _form);
+            syn::parse2(quote_spanned!(span => {
+                let __result: #_form::Result<'_, ()> = #expr;
+                __result
+            })).unwrap()
+        });
+
+        Ok(exprs)
 }

core/codegen/tests/ui-fail-nightly/from_form.stderr

@@ -336,3 +336,44 @@ note: error occurred while deriving `FromForm`
 136 | #[derive(FromForm)]
     |          ^^^^^^^^
     = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0425]: cannot find function `unknown` in this scope
+   --> $DIR/from_form.rs:150:24
+    |
+150 |     #[field(validate = unknown())]
+    |                        ^^^^^^^ not found in this scope
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:144:24
+    |
+144 |     #[field(validate = 123)]
+    |             --------   ^^^ expected enum `Result`, found integer
+    |             |
+    |             expected due to this
+    |
+    = note: expected enum `Result<(), Errors<'_>>`
+               found type `{integer}`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:157:5
+    |
+157 |     first: String,
+    |     ^^^^^^^^^^^^^ expected enum `TempFile`, found struct `std::string::String`
+    |
+    = note: expected reference `&TempFile<'_>`
+               found reference `&std::string::String`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:163:5
+    |
+163 |     first: String,
+    |     ^^^^^^^^^^^^^ expected enum `TempFile`, found struct `std::string::String`
+    |
+    = note: expected reference `&TempFile<'_>`
+               found reference `&std::string::String`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:162:28
+    |
+162 |     #[field(validate = ext("hello"))]
+    |                            ^^^^^^^ expected struct `ContentType`, found `&str`

core/codegen/tests/ui-fail-stable/from_form.stderr

@@ -359,3 +359,44 @@ error: [note] error occurred while deriving `FromForm`
     |          ^^^^^^^^
     |
     = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0425]: cannot find function `unknown` in this scope
+   --> $DIR/from_form.rs:150:24
+    |
+150 |     #[field(validate = unknown())]
+    |                        ^^^^^^^ not found in this scope
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:144:24
+    |
+144 |     #[field(validate = 123)]
+    |             --------   ^^^ expected enum `std::result::Result`, found integer
+    |             |
+    |             expected due to this
+    |
+    = note: expected enum `std::result::Result<(), Errors<'_>>`
+               found type `{integer}`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:157:12
+    |
+157 |     first: String,
+    |            ^^^^^^ expected enum `TempFile`, found struct `std::string::String`
+    |
+    = note: expected reference `&TempFile<'_>`
+               found reference `&std::string::String`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:163:12
+    |
+163 |     first: String,
+    |            ^^^^^^ expected enum `TempFile`, found struct `std::string::String`
+    |
+    = note: expected reference `&TempFile<'_>`
+               found reference `&std::string::String`
+
+error[E0308]: mismatched types
+   --> $DIR/from_form.rs:162:28
+    |
+162 |     #[field(validate = ext("hello"))]
+    |                            ^^^^^^^ expected struct `ContentType`, found `&str`

core/codegen/tests/ui-fail/from_form.rs

@@ -139,4 +139,28 @@ struct BadName3 {
     field: String,
 }
 
+#[derive(FromForm)]
+struct Validate0 {
+    #[field(validate = 123)]
+    first: String,
+}
+
+#[derive(FromForm)]
+struct Validate1 {
+    #[field(validate = unknown())]
+    first: String,
+}
+
+#[derive(FromForm)]
+struct Validate2 {
+    #[field(validate = ext(rocket::http::ContentType::HTML))]
+    first: String,
+}
+
+#[derive(FromForm)]
+struct Validate3 {
+    #[field(validate = ext("hello"))]
+    first: String,
+}
+
 fn main() { }

examples/forms/src/main.rs

@@ -1,6 +1,6 @@
 #[macro_use]extern crate rocket;
 
-use rocket::http::Status;
+use rocket::http::{Status, ContentType};
 use rocket::form::{Form, Contextual, FromForm, FromFormField, Context};
 use rocket::data::TempFile;
 
@@ -39,7 +39,7 @@ struct Submission<'v> {
     date: time::Date,
     #[field(validate = len(1..=250))]
     r#abstract: &'v str,
-    #[field(validate = ext("pdf"))]
+    #[field(validate = ext(ContentType::PDF))]
     file: TempFile<'v>,
     #[field(validate = len(1..))]
     category: Vec<Category>,
@@ -52,8 +52,7 @@ struct Account<'v> {
     #[field(validate = len(1..))]
     name: &'v str,
     password: Password<'v>,
-    #[field(validate = contains('@'))]
-    #[field(validate = omits(self.password.first))]
+    #[field(validate = contains('@').or_else(msg!("invalid email address")))]
     email: &'v str,
 }