editoast: add ToToken ModelV2 definition ChangesetFromModelImpl

Author: leovalais

editoast/editoast_derive/src/modelv2.rs

@@ -29,7 +29,7 @@ pub fn model(input: &DeriveInput) -> Result<TokenStream> {
     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 changeset_from_model_impl = config.changeset_from_model_impl();
 
     let cs_builder = config.make_builder(true);
     let patch_builder = config.make_builder(false);
@@ -45,8 +45,8 @@ pub fn model(input: &DeriveInput) -> Result<TokenStream> {
         #preferred_id_impl
 
         #model_from_row_impl
+        #changeset_from_model_impl
 
-        #from_impls
         #cs_builder
         #patch_builder
         #model_impls

editoast/editoast_derive/src/modelv2/codegen.rs

@@ -1,4 +1,5 @@
 mod changeset_decl;
+mod changeset_from_model;
 mod identifiable_impl;
 mod model_from_row_impl;
 mod model_impl;
@@ -7,13 +8,15 @@ mod row_decl;
 
 use proc_macro2::{Span, TokenStream};
 use quote::quote;
+use syn::parse_quote;
 
 use crate::modelv2::codegen::changeset_decl::ChangesetDecl;
 use crate::modelv2::codegen::changeset_decl::ChangesetFieldDecl;
 use crate::modelv2::codegen::model_impl::ModelImpl;
 use crate::modelv2::codegen::row_decl::RowDecl;
 use crate::modelv2::codegen::row_decl::RowFieldDecl;
 
+use self::changeset_from_model::ChangesetFromModelImpl;
 use self::identifiable_impl::IdentifiableImpl;
 use self::model_from_row_impl::ModelFromRowImpl;
 use self::preferred_id_impl::PreferredIdImpl;
@@ -75,7 +78,7 @@ impl ModelConfig {
             .filter(|field| !field.builder_skip)
             .map(|field| {
                 let ident = &field.ident;
-                let expr = field.into_transformed(quote! { #ident });
+                let expr = field.into_transformed(parse_quote! { #ident });
                 let body = if changeset {
                     quote! { self.#ident = Some(#expr) }
                 } else {
@@ -153,26 +156,16 @@ impl ModelConfig {
         }
     }
 
-    pub fn make_from_impls(&self) -> TokenStream {
-        let model = &self.model;
-        let (cs_field, cs_value): (Vec<_>, Vec<_>) = self
-            .iter_fields()
-            .filter(|f| !self.is_primary(f))
-            .map(|field| {
-                let ident = &field.ident;
-                (ident, field.into_transformed(quote! { model.#ident }))
-            })
-            .unzip();
-        let cs_ident = self.changeset.ident();
-        quote! {
-            #[automatically_derived]
-            impl From<#model> for #cs_ident {
-                fn from(model: #model) -> Self {
-                    Self {
-                        #( #cs_field: Some(#cs_value) ),*
-                    }
-                }
-            }
+    pub(crate) fn changeset_from_model_impl(&self) -> ChangesetFromModelImpl {
+        ChangesetFromModelImpl {
+            model: self.model.clone(),
+            changeset: self.changeset.ident(),
+            fields: self
+                .fields
+                .iter()
+                .filter(|f| !self.is_primary(f))
+                .cloned()
+                .collect(),
         }
     }
 

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

@@ -0,0 +1,39 @@
+use crate::modelv2::utils::np;
+use crate::modelv2::ModelField;
+use quote::quote;
+use quote::ToTokens;
+use syn::parse_quote;
+
+pub(crate) struct ChangesetFromModelImpl {
+    pub(super) model: syn::Ident,
+    pub(super) changeset: syn::Ident,
+    pub(super) fields: Vec<ModelField>,
+}
+
+impl ToTokens for ChangesetFromModelImpl {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let Self {
+            model,
+            changeset,
+            fields,
+        } = self;
+        let np!(field, value): np!(vec2) = fields
+            .iter()
+            .map(|field| {
+                let ident = &field.ident;
+                let expr = field.into_transformed(parse_quote! { model.#ident });
+                (ident, expr)
+            })
+            .unzip();
+        tokens.extend(quote! {
+            #[automatically_derived]
+            impl From<#model> for #changeset {
+                fn from(model: #model) -> Self {
+                    Self {
+                        #( #field: Some(#value) ),*
+                    }
+                }
+            }
+        });
+    }
+}

editoast/editoast_derive/src/modelv2/config.rs

@@ -3,8 +3,6 @@ use std::{
     ops::{Deref, DerefMut},
 };
 
-use proc_macro2::TokenStream;
-use quote::quote;
 use syn::parse_quote;
 
 use super::{args::GeneratedTypeArgs, identifier::Identifier};
@@ -112,16 +110,16 @@ impl ModelConfig {
 
 impl ModelField {
     #[allow(clippy::wrong_self_convention)]
-    pub fn into_transformed(&self, expr: TokenStream) -> TokenStream {
+    pub fn into_transformed(&self, expr: syn::Expr) -> syn::Expr {
         match self.transform {
-            Some(FieldTransformation::Remote(_)) => quote! { #expr.into() },
-            Some(FieldTransformation::Json) => quote! { diesel_json::Json(#expr) },
+            Some(FieldTransformation::Remote(_)) => parse_quote! { #expr.into() },
+            Some(FieldTransformation::Json) => parse_quote! { diesel_json::Json(#expr) },
             Some(FieldTransformation::Geo) => unimplemented!("to be designed"),
-            Some(FieldTransformation::ToString) => quote! { #expr.to_string() },
+            Some(FieldTransformation::ToString) => parse_quote! { #expr.to_string() },
             Some(FieldTransformation::ToEnum(_)) => {
-                quote! { #expr as i16 }
+                parse_quote! { #expr as i16 }
             }
-            None => quote! { #expr },
+            None => parse_quote! { #expr },
         }
     }