Derive TypeInfo for own types

.github/workflows/rust.yml

@@ -40,6 +40,7 @@ jobs:
     - name: check-features
       run: |
         cargo check --no-default-features --features bit-vec
+        cargo check --no-default-features --features dogfood
         cargo check --no-default-features --features docs
         cargo check --no-default-features --features serde
         cargo check --no-default-features --features serde,decode

Cargo.toml

@@ -31,11 +31,15 @@ std = [
 derive = [
     "scale-info-derive"
 ]
+# Derive `TypeInfo` for our own types.
+dogfood = [
+    "derive"
+]
 # Include rustdoc strings in the type metadata.
 docs = [
     "scale-info-derive/docs"
 ]
-# enables decoding and deserialization of portable scale-info type metadata
+# Enables decoding and deserialization of portable scale-info type metadata.
 decode = [
     "scale/full"
 ]

derive/src/lib.rs

@@ -76,6 +76,7 @@ struct TypeInfoImpl {
 impl TypeInfoImpl {
     fn parse(input: TokenStream2) -> Result<Self> {
         let ast: DeriveInput = syn::parse2(input)?;
+
         let attrs = attr::Attributes::from_ast(&ast)?;
 
         Ok(Self { ast, attrs })
@@ -98,12 +99,16 @@ impl TypeInfoImpl {
         let type_params = self.ast.generics.type_params().map(|tp| {
             let ty_ident = &tp.ident;
             let ty = if self.attrs.skip_type_params().map_or(true, |skip| !skip.skip(tp)) {
-                quote! { ::core::option::Option::Some(#scale_info::meta_type::<#ty_ident>()) }
+
+            quote! { ::core::option::Option::Some(:: #scale_info ::meta_type::<#ty_ident>()) }
+
             } else {
                 quote! { ::core::option::Option::None }
             };
             quote! {
-                #scale_info::TypeParameter::new(::core::stringify!(#ty_ident), #ty)
+
+                :: #scale_info ::TypeParameter::new(::core::stringify!(#ty_ident), #ty)
+
             }
         });
 
@@ -117,12 +122,14 @@ impl TypeInfoImpl {
         let docs = self.generate_docs(&self.ast.attrs);
 
         Ok(quote! {
-            impl #impl_generics #scale_info::TypeInfo for #ident #ty_generics #where_clause {
+            impl #impl_generics :: #scale_info ::TypeInfo for #ident #ty_generics #where_clause {
+
                 type Identity = Self;
+
                 fn type_info() -> #scale_info::Type {
-                    #scale_info::Type::builder()
-                        .path(#scale_info::Path::new(::core::stringify!(#ident), ::core::module_path!()))
-                        .type_params(#scale_info::prelude::vec![ #( #type_params ),* ])
+                    #scale_info ::Type::builder()
+                        .path(#scale_info ::Path::new(::core::stringify!(#ident), ::core::module_path!()))
+                        .type_params(#scale_info ::prelude::vec![ #( #type_params ),* ])
                         #docs
                         .#build_type
                 }
@@ -152,7 +159,7 @@ impl TypeInfoImpl {
         };
 
         quote! {
-            composite(#scale_info::build::Fields::#fields)
+            composite(:: #scale_info ::build::Fields::#fields)
         }
     }
 
@@ -252,7 +259,8 @@ impl TypeInfoImpl {
             });
         quote! {
             variant(
-                #scale_info::build::Variants::new()
+                :: #scale_info ::build::Variants::new()
+
                     #( #variants )*
             )
         }
@@ -294,6 +302,23 @@ impl TypeInfoImpl {
     }
 }
 
+// /// Find the name given to the `scale-info` crate in the context we run in. If scale-info is not
+// /// among the dependencies then we must be deriving types for the scale-info crate itself, in which
+// /// case we need to refer to it using the reserved word "crate", so the object paths keep working.
+// fn scale_info_crate_path() -> Result<syn::Path> {
+//     use proc_macro_crate::FoundCrate;
+//     const SCALE_INFO_CRATE_NAME: &str = "scale-info";
+
+//     let crate_ident = match proc_macro_crate::crate_name(SCALE_INFO_CRATE_NAME) {
+//         Ok(FoundCrate::Itself) => parse_quote! { crate },
+//         Ok(FoundCrate::Name(name)) => {
+//             let crate_ident = Ident::new(&name, Span::call_site());
+//             parse_quote! { :: #crate_ident }
+//         }
+//         Err(e) => return Err(syn::Error::new(Span::call_site(), e)),
+//     };
+//     Ok(crate_ident)
+
 /// Get the name of a crate, to be robust against renamed dependencies.
 fn crate_name_path(name: &str) -> Result<syn::Path> {
     proc_macro_crate::crate_name(name)

src/form.rs

@@ -60,6 +60,7 @@ pub trait Form {
 /// through the registry and `IntoPortable`.
 #[cfg_attr(feature = "serde", derive(Serialize))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub enum MetaForm {}
 
 impl Form for MetaForm {

src/interner.rs

@@ -46,6 +46,7 @@ use serde::{
 )]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "serde", serde(transparent))]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct UntrackedSymbol<T> {
     /// The index to the symbol in the interner table.
     #[codec(compact)]

src/ty/composite.rs

@@ -70,6 +70,7 @@ use serde::{
 #[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug, From, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefComposite<T: Form = MetaForm> {
     /// The fields of the composite type.
     #[cfg_attr(

src/ty/fields.rs

@@ -73,6 +73,7 @@ use serde::{
 #[cfg_attr(feature = "serde", serde(rename_all = "camelCase"))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct Field<T: Form = MetaForm> {
     /// The name of the field. None for unnamed fields.
     #[cfg_attr(

src/ty/mod.rs

@@ -52,6 +52,7 @@ pub use self::{
 
 /// A [`Type`] definition with optional metadata.
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 #[cfg_attr(
     feature = "serde",
     serde(bound(
@@ -119,7 +120,7 @@ impl_from_type_def_for_type!(
 );
 
 impl Type {
-    /// Create a [`TypeBuilder`](`crate::build::TypeBuilder`) the public API for constructing a [`Type`]
+    /// Create a [`TypeBuilder`](`crate::build::TypeBuilder`), the public API for constructing a [`Type`]
     pub fn builder() -> TypeBuilder {
         TypeBuilder::default()
     }
@@ -244,6 +245,7 @@ where
 #[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, From, Debug, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub enum TypeDef<T: Form = MetaForm> {
     /// A composite type (e.g. a struct or a tuple)
     #[codec(index = 0)]
@@ -297,6 +299,7 @@ impl IntoPortable for TypeDef {
 #[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Encode, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub enum TypeDefPrimitive {
     /// `bool` type
     #[codec(index = 0)]
@@ -349,6 +352,7 @@ pub enum TypeDefPrimitive {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Encode, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefArray<T: Form = MetaForm> {
     /// The length of the array type.
     len: u32,
@@ -403,6 +407,7 @@ where
 #[cfg_attr(feature = "serde", serde(transparent))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Encode, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefTuple<T: Form = MetaForm> {
     /// The types of the tuple fields.
     fields: Vec<T::Type>,
@@ -452,6 +457,7 @@ where
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Encode, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefSequence<T: Form = MetaForm> {
     /// The element type of the sequence type.
     #[cfg_attr(feature = "serde", serde(rename = "type"))]
@@ -502,6 +508,7 @@ where
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Encode, Debug)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefCompact<T: Form = MetaForm> {
     /// The type wrapped in [`Compact`], i.e. the `T` in `Compact<T>`.
     #[cfg_attr(feature = "serde", serde(rename = "type"))]

src/ty/path.rs

@@ -58,6 +58,7 @@ use serde::{
 #[cfg_attr(feature = "serde", serde(transparent))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct Path<T: Form = MetaForm> {
     /// The segments of the namespace.
     segments: Vec<T::String>,

src/ty/variant.rs

@@ -82,6 +82,7 @@ use serde::{
 #[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug, From, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct TypeDefVariant<T: Form = MetaForm> {
     /// The variants of a variant type
     #[cfg_attr(
@@ -148,6 +149,7 @@ where
 )]
 #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug, Encode)]
+#[cfg_attr(feature = "dogfood", derive(scale_info_derive::TypeInfo))]
 pub struct Variant<T: Form = MetaForm> {
     /// The name of the variant.
     name: T::String,