Compatibility with diesel master after 72bfb356

.github/workflows/CI.yaml

@@ -10,7 +10,7 @@ jobs:
       matrix:
         rust:
           - stable
-          - 1.40.0
+          - 1.48.0
 
     services:
       postgres:

src/lib.rs

@@ -13,40 +13,41 @@ use syn::*;
 /// # Attributes
 ///
 /// ## Type attributes
-/// 
-/// * `#[PgType = "new_enum"]` specifies postgres name for the enum type. If ommitted, uses the enum's name in snake_case.
-/// * `#[PgSchema = "schema"]` specifies the postgres schema containing the enum type. If omitted, diesel uses the default search path, but this can cause problems with caching.
-/// * `#[DieselType = "NewEnumMapping"]` specifies the name for the diesel type. If omitted, uses the name + `Mapping`.
+///
+/// * `#[DieselExistingType = "crate::schema::sql_types::NewEnum"]` specifies the name for the corresponding diesel type that was already created by the diesel CLI. If omitted, uses `crate::schema::sql_types::EnumName`.
+/// * `#[DieselType = "NewEnumMapping"]` specifies the name for the diesel type to create for Mysql or Sqlite. If omitted, uses the name + `Mapping`.
 /// * `#[DbValueStyle = "snake_case"]` specifies a renaming style from each of the rust enum variants to each of the database variants. Either `camelCase`, `kebab-case`, `PascalCase`, `SCREAMING_SNAKE_CASE`, `snake_case`, `verbatim`. If omitted, uses `snake_case`.
 ///
 /// ## Variant attributes
 ///
 /// * `#[db_rename = "variant"]` specifies the db name for a specific variant.
-#[proc_macro_derive(DbEnum, attributes(PgType, PgSchema, DieselType, DbValueStyle, db_rename))]
+#[proc_macro_derive(
+    DbEnum,
+    attributes(DieselType, DieselExistingType, DbValueStyle, db_rename)
+)]
 pub fn derive(input: TokenStream) -> TokenStream {
     let input: DeriveInput = parse_macro_input!(input as DeriveInput);
-    let db_type =
-        type_from_attrs(&input.attrs, "PgType").unwrap_or(input.ident.to_string().to_snake_case());
-    let db_schema =
-        type_from_attrs(&input.attrs, "PgSchema");
-    let diesel_mapping =
+    let diesel_existing_mapping = type_from_attrs(&input.attrs, "DieselExistingType")
+        .unwrap_or(format!("crate::schema::sql_types::{}", input.ident));
+    let new_diesel_mapping =
         type_from_attrs(&input.attrs, "DieselType").unwrap_or(format!("{}Mapping", input.ident));
 
     // Maintain backwards compatibility by defaulting to snake case.
     let case_style =
         type_from_attrs(&input.attrs, "DbValueStyle").unwrap_or("snake_case".to_string());
     let case_style = CaseStyle::from_string(&case_style);
 
-    let diesel_mapping = Ident::new(diesel_mapping.as_ref(), Span::call_site());
+    let diesel_existing_mapping: proc_macro2::TokenStream =
+        diesel_existing_mapping.parse().unwrap();
+    let new_diesel_mapping = Ident::new(new_diesel_mapping.as_ref(), Span::call_site());
     let quoted = if let Data::Enum(syn::DataEnum {
         variants: data_variants,
         ..
     }) = input.data
     {
         generate_derive_enum_impls(
-            &db_type,
-            db_schema.as_deref(),
-            &diesel_mapping,
+            &diesel_existing_mapping,
+            &new_diesel_mapping,
             case_style,
             &input.ident,
             &data_variants,
@@ -103,9 +104,8 @@ impl CaseStyle {
 }
 
 fn generate_derive_enum_impls(
-    db_type: &str,
-    db_schema: Option<&str>,
-    diesel_mapping: &Ident,
+    diesel_existing_mapping: &proc_macro2::TokenStream,
+    new_diesel_mapping: &Ident,
     case_style: CaseStyle,
     enum_ty: &Ident,
     variants: &syn::punctuated::Punctuated<Variant, syn::token::Comma>,
@@ -137,30 +137,72 @@ fn generate_derive_enum_impls(
     let variants_rs: &[proc_macro2::TokenStream] = &variant_ids;
     let variants_db: &[LitByteStr] = &variants_db;
 
-    let common_impl =
-        generate_common_impl(db_type, db_schema, diesel_mapping, enum_ty, variants_rs, variants_db);
+    let (common_diesel_mapping, common_diesel_mapping_use) =
+        if cfg!(feature = "mysql") || cfg!(feature = "sqlite") {
+            let new_diesel_mapping_impl = generate_common_diesel_mapping(new_diesel_mapping);
+            let common_impls_on_new_diesel_mapping = generate_common_impls(
+                &quote! { #new_diesel_mapping },
+                enum_ty,
+                variants_rs,
+                variants_db,
+            );
+            (
+                quote! {
+                    #new_diesel_mapping_impl
+                    #common_impls_on_new_diesel_mapping
+                },
+                quote! {
+                    pub use self::#modname::#new_diesel_mapping;
+                },
+            )
+        } else {
+            (quote! {}, quote! {})
+        };
 
     let pg_impl = if cfg!(feature = "postgres") {
-        generate_postgres_impl(diesel_mapping, enum_ty, variants_rs, variants_db)
+        let common_impls_on_existing_diesel_mapping =
+            generate_common_impls(diesel_existing_mapping, enum_ty, variants_rs, variants_db);
+        let postgres_impl =
+            generate_postgres_impl(diesel_existing_mapping, enum_ty, variants_rs, variants_db);
+        quote! {
+            #common_impls_on_existing_diesel_mapping
+            #postgres_impl
+        }
     } else {
         quote! {}
     };
     let mysql_impl = if cfg!(feature = "mysql") {
-        generate_mysql_impl(diesel_mapping, enum_ty, variants_rs, variants_db)
+        generate_mysql_impl(new_diesel_mapping, enum_ty, variants_rs, variants_db)
     } else {
         quote! {}
     };
     let sqlite_impl = if cfg!(feature = "sqlite") {
-        generate_sqlite_impl(diesel_mapping, enum_ty, variants_rs, variants_db)
+        generate_sqlite_impl(new_diesel_mapping, enum_ty, variants_rs, variants_db)
     } else {
         quote! {}
     };
 
+    let imports = quote! {
+        use super::*;
+        use diesel::Queryable;
+        use diesel::backend::{self, Backend};
+        use diesel::expression::AsExpression;
+        use diesel::expression::bound::Bound;
+        use diesel::row::Row;
+        use diesel::sql_types::*;
+        use diesel::serialize::{self, ToSql, IsNull, Output};
+        use diesel::deserialize::{self, FromSql};
+        use diesel::query_builder::QueryId;
+        use std::io::Write;
+    };
+
     let quoted = quote! {
-        pub use self::#modname::#diesel_mapping;
+        #common_diesel_mapping_use
         #[allow(non_snake_case)]
         mod #modname {
-            #common_impl
+            #imports
+
+            #common_diesel_mapping
             #pg_impl
             #mysql_impl
             #sqlite_impl
@@ -181,33 +223,22 @@ fn stylize_value(value: &str, style: CaseStyle) -> String {
     }
 }
 
-fn generate_common_impl(
-    db_type: &str,
-    db_schema: Option<&str>,
-    diesel_mapping: &Ident,
+fn generate_common_diesel_mapping(new_diesel_mapping: &Ident) -> proc_macro2::TokenStream {
+    quote! {
+        #[derive(SqlType, Clone)]
+        #[mysql_type = "Enum"]
+        #[sqlite_type = "Text"]
+        pub struct #new_diesel_mapping;
+    }
+}
+
+fn generate_common_impls(
+    diesel_mapping: &proc_macro2::TokenStream,
     enum_ty: &Ident,
     variants_rs: &[proc_macro2::TokenStream],
     variants_db: &[LitByteStr],
 ) -> proc_macro2::TokenStream {
-    let db_schema = db_schema.into_iter();
     quote! {
-        use super::*;
-        use diesel::Queryable;
-        use diesel::backend::{self, Backend};
-        use diesel::expression::AsExpression;
-        use diesel::expression::bound::Bound;
-        use diesel::row::Row;
-        use diesel::sql_types::*;
-        use diesel::serialize::{self, ToSql, IsNull, Output};
-        use diesel::deserialize::{self, FromSql};
-        use diesel::query_builder::QueryId;
-        use std::io::Write;
-
-        #[derive(SqlType, Clone)]
-        #[postgres(type_name = #db_type, #(type_schema = #db_schema)*)]
-        #[mysql_type = "Enum"]
-        #[sqlite_type = "Text"]
-        pub struct #diesel_mapping;
         impl QueryId for #diesel_mapping {
             type QueryId = #diesel_mapping;
             const HAS_STATIC_QUERY_ID: bool = true;
@@ -283,7 +314,7 @@ fn generate_common_impl(
 }
 
 fn generate_postgres_impl(
-    diesel_mapping: &Ident,
+    diesel_mapping: &proc_macro2::TokenStream,
     enum_ty: &Ident,
     variants_rs: &[proc_macro2::TokenStream],
     variants_db: &[LitByteStr],
@@ -293,6 +324,12 @@ fn generate_postgres_impl(
             use super::*;
             use diesel::pg::{Pg, PgValue};
 
+            impl Clone for #diesel_mapping {
+                fn clone(&self) -> Self {
+                    #diesel_mapping
+                }
+            }
+
             impl FromSql<#diesel_mapping, Pg> for #enum_ty {
                 fn from_sql(raw: PgValue) -> deserialize::Result<Self> {
                     match raw.as_bytes() {