editoast: add ToToken ModelV2 definition ModelFromRowImpl

Author: leovalais

editoast/editoast_derive/src/modelv2.rs

@@ -28,6 +28,7 @@ pub fn model(input: &DeriveInput) -> Result<TokenStream> {
     let identifiable_impls = config.identifiable_impls();
     let preferred_id_impl = config.preferred_id_impl();
 
+    let model_from_row_impl = config.model_from_row_impl();
     let from_impls = config.make_from_impls();
 
     let cs_builder = config.make_builder(true);
@@ -43,6 +44,8 @@ pub fn model(input: &DeriveInput) -> Result<TokenStream> {
         #(#identifiable_impls)*
         #preferred_id_impl
 
+        #model_from_row_impl
+
         #from_impls
         #cs_builder
         #patch_builder

editoast/editoast_derive/src/modelv2/codegen.rs

@@ -1,5 +1,6 @@
 mod changeset_decl;
 mod identifiable_impl;
+mod model_from_row_impl;
 mod model_impl;
 mod preferred_id_impl;
 mod row_decl;
@@ -14,6 +15,7 @@ use crate::modelv2::codegen::row_decl::RowDecl;
 use crate::modelv2::codegen::row_decl::RowFieldDecl;
 
 use self::identifiable_impl::IdentifiableImpl;
+use self::model_from_row_impl::ModelFromRowImpl;
 use self::preferred_id_impl::PreferredIdImpl;
 
 use super::utils::np;
@@ -143,15 +145,16 @@ impl ModelConfig {
         }
     }
 
+    pub(crate) fn model_from_row_impl(&self) -> ModelFromRowImpl {
+        ModelFromRowImpl {
+            model: self.model.clone(),
+            row: self.row.ident(),
+            fields: self.fields.clone(),
+        }
+    }
+
     pub fn make_from_impls(&self) -> TokenStream {
         let model = &self.model;
-        let (row_field, row_value): (Vec<_>, Vec<_>) = self
-            .iter_fields()
-            .map(|field| {
-                let ident = &field.ident;
-                (ident, field.from_transformed(quote! { row.#ident }))
-            })
-            .unzip();
         let (cs_field, cs_value): (Vec<_>, Vec<_>) = self
             .iter_fields()
             .filter(|f| !self.is_primary(f))
@@ -160,18 +163,8 @@ impl ModelConfig {
                 (ident, field.into_transformed(quote! { model.#ident }))
             })
             .unzip();
-        let row_ident = self.row.ident();
         let cs_ident = self.changeset.ident();
         quote! {
-            #[automatically_derived]
-            impl From<#row_ident> for #model {
-                fn from(row: #row_ident) -> Self {
-                    Self {
-                        #( #row_field: #row_value ),*
-                    }
-                }
-            }
-
             #[automatically_derived]
             impl From<#model> for #cs_ident {
                 fn from(model: #model) -> Self {

editoast/editoast_derive/src/modelv2/codegen/model_from_row_impl.rs

@@ -0,0 +1,35 @@
+use crate::modelv2::utils::np;
+use crate::modelv2::ModelField;
+use quote::quote;
+use quote::ToTokens;
+use syn::parse_quote;
+
+pub(crate) struct ModelFromRowImpl {
+    pub(super) model: syn::Ident,
+    pub(super) row: syn::Ident,
+    pub(super) fields: Vec<ModelField>,
+}
+
+impl ToTokens for ModelFromRowImpl {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let Self { model, row, fields } = self;
+        let np!(field, value): np!(vec2) = fields
+            .iter()
+            .map(|field| {
+                let ident = &field.ident;
+                let expr = field.from_transformed(parse_quote! { row.#ident });
+                (ident, expr)
+            })
+            .unzip();
+        tokens.extend(quote! {
+            #[automatically_derived]
+            impl From<#row> for #model {
+                fn from(row: #row) -> Self {
+                    Self {
+                        #( #field: #value ),*
+                    }
+                }
+            }
+        });
+    }
+}

editoast/editoast_derive/src/modelv2/config.rs

@@ -126,16 +126,16 @@ impl ModelField {
     }
 
     #[allow(clippy::wrong_self_convention)]
-    pub fn from_transformed(&self, expr: TokenStream) -> TokenStream {
+    pub fn from_transformed(&self, expr: syn::Expr) -> syn::Expr {
         match self.transform {
-            Some(FieldTransformation::Remote(_)) => quote! { #expr.into() },
-            Some(FieldTransformation::Json) => quote! { #expr.0 },
+            Some(FieldTransformation::Remote(_)) => parse_quote! { #expr.into() },
+            Some(FieldTransformation::Json) => parse_quote! { #expr.0 },
             Some(FieldTransformation::Geo) => unimplemented!("to be designed"),
-            Some(FieldTransformation::ToString) => quote! { String::from(#expr.parse()) },
+            Some(FieldTransformation::ToString) => parse_quote! { String::from(#expr.parse()) },
             Some(FieldTransformation::ToEnum(ref ty)) => {
-                quote! { #ty::from_repr(#expr as usize).expect("Invalid variant repr") }
+                parse_quote! { #ty::from_repr(#expr as usize).expect("Invalid variant repr") }
             }
-            None => quote! { #expr },
+            None => parse_quote! { #expr },
         }
     }