add json optional attribute parser and expansion

launchbadge · Jan 10, 2025 · 5c5fd3f · 5c5fd3f
1 parent 6b33766
commit 5c5fd3f
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Showing 2 changed files with 36 additions and 14 deletions.
diff --git a/sqlx-macros-core/src/derives/attributes.rs b/sqlx-macros-core/src/derives/attributes.rs
@@ -1,8 +1,7 @@
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::quote_spanned;
 use syn::{
-    punctuated::Punctuated, token::Comma, Attribute, DeriveInput, Field, LitStr, Meta, Token, Type,
-    Variant,
+    parenthesized, parse::discouraged::AnyDelimiter, punctuated::Punctuated, token::{self, Comma}, Attribute, DeriveInput, Field, LitStr, Meta, Token, Type, Variant
 };
 
 macro_rules! assert_attribute {
@@ -61,13 +60,18 @@ pub struct SqlxContainerAttributes {
     pub default: bool,
 }
 
+pub enum JsonAttribute {
+    Mandatory,
+    Optional
+}
+
 pub struct SqlxChildAttributes {
     pub rename: Option<String>,
     pub default: bool,
     pub flatten: bool,
     pub try_from: Option<Type>,
     pub skip: bool,
-    pub json: bool,
+    pub json: Option<JsonAttribute>,
 }
 
 pub fn parse_container_attributes(input: &[Attribute]) -> syn::Result<SqlxContainerAttributes> {
@@ -144,7 +148,7 @@ pub fn parse_child_attributes(input: &[Attribute]) -> syn::Result<SqlxChildAttri
     let mut try_from = None;
     let mut flatten = false;
     let mut skip: bool = false;
-    let mut json = false;
+    let mut json = None;
 
     for attr in input.iter().filter(|a| a.path().is_ident("sqlx")) {
         attr.parse_nested_meta(|meta| {
@@ -163,7 +167,14 @@ pub fn parse_child_attributes(input: &[Attribute]) -> syn::Result<SqlxChildAttri
             } else if meta.path.is_ident("skip") {
                 skip = true;
             } else if meta.path.is_ident("json") {
-                json = true;
+                if meta.input.peek(syn::token::Paren) {
+                    let content;
+                    parenthesized!(content in meta.input);
+                    let literal: Token![optional] = content.parse()?;
+                    json = Some(JsonAttribute::Optional);
+                } else {
+                    json = Some(JsonAttribute::Mandatory);
+                }
             }
 
             Ok(())

diff --git a/sqlx-macros-core/src/derives/row.rs b/sqlx-macros-core/src/derives/row.rs
@@ -6,7 +6,7 @@ use syn::{
 };
 
 use super::{
-    attributes::{parse_child_attributes, parse_container_attributes},
+    attributes::{parse_child_attributes, parse_container_attributes, JsonAttribute},
     rename_all,
 };
 
@@ -99,20 +99,20 @@ fn expand_derive_from_row_struct(
 
             let expr: Expr = match (attributes.flatten, attributes.try_from, attributes.json) {
                 // <No attributes>
-                (false, None, false) => {
+                (false, None, None) => {
                     predicates
                         .push(parse_quote!(#ty: ::sqlx::decode::Decode<#lifetime, R::Database>));
                     predicates.push(parse_quote!(#ty: ::sqlx::types::Type<R::Database>));
 
                     parse_quote!(__row.try_get(#id_s))
                 }
                 // Flatten
-                (true, None, false) => {
+                (true, None, None) => {
                     predicates.push(parse_quote!(#ty: ::sqlx::FromRow<#lifetime, R>));
                     parse_quote!(<#ty as ::sqlx::FromRow<#lifetime, R>>::from_row(__row))
                 }
                 // Flatten + Try from
-                (true, Some(try_from), false) => {
+                (true, Some(try_from), None) => {
                     predicates.push(parse_quote!(#try_from: ::sqlx::FromRow<#lifetime, R>));
                     parse_quote!(
                         <#try_from as ::sqlx::FromRow<#lifetime, R>>::from_row(__row)
@@ -130,11 +130,11 @@ fn expand_derive_from_row_struct(
                     )
                 }
                 // Flatten + Json
-                (true, _, true) => {
+                (true, _, Some(_)) => {
                     panic!("Cannot use both flatten and json")
                 }
                 // Try from
-                (false, Some(try_from), false) => {
+                (false, Some(try_from), None) => {
                     predicates
                         .push(parse_quote!(#try_from: ::sqlx::decode::Decode<#lifetime, R::Database>));
                     predicates.push(parse_quote!(#try_from: ::sqlx::types::Type<R::Database>)); 
@@ -154,8 +154,8 @@ fn expand_derive_from_row_struct(
                             })
                     )
                 }
-                // Try from + Json
-                (false, Some(try_from), true) => {
+                // Try from + Json mandatory
+                (false, Some(try_from), Some(JsonAttribute::Mandatory)) => {
                     predicates
                         .push(parse_quote!(::sqlx::types::Json<#try_from>: ::sqlx::decode::Decode<#lifetime, R::Database>));
                     predicates.push(parse_quote!(::sqlx::types::Json<#try_from>: ::sqlx::types::Type<R::Database>));
@@ -175,14 +175,25 @@ fn expand_derive_from_row_struct(
                             })
                     )
                 },
+                // Try from + Json optional
+                (false, Some(try_from), Some(JsonAttribute::Optional)) => {
+                    panic!("Cannot use both try from and json optional")
+                },
                 // Json
-                (false, None, true) => {
+                (false, None, Some(JsonAttribute::Mandatory)) => {
                     predicates
                         .push(parse_quote!(::sqlx::types::Json<#ty>: ::sqlx::decode::Decode<#lifetime, R::Database>));
                     predicates.push(parse_quote!(::sqlx::types::Json<#ty>: ::sqlx::types::Type<R::Database>));
 
                     parse_quote!(__row.try_get::<::sqlx::types::Json<_>, _>(#id_s).map(|x| x.0))
                 },
+                (false, None, Some(JsonAttribute::Optional)) => {
+                    predicates
+                        .push(parse_quote!(::core::Option<::sqlx::types::Json<#ty>>: ::sqlx::decode::Decode<#lifetime, R::Database>));
+                    predicates.push(parse_quote!(::core::Option<::sqlx::types::Json<#ty>>: ::sqlx::types::Type<R::Database>));
+
+                    parse_quote!(__row.try_get::<::core::Option<::sqlx::types::Json<_>>, _>(#id_s).map(|x| x.map(|y| y.0)))
+                },
             };
 
             if attributes.default {