Add Deserialize implementations for input objects

example_with_targets/schema.graphql

@@ -8,6 +8,11 @@ Only allow the field to be queried when targeting one of the specified targets.
 """
 directive @restrictTarget(only: [String!]!) on FIELD_DEFINITION
 
+"""
+Requires that exactly one field must be supplied and that field must not be `null`.
+"""
+directive @oneOf on INPUT_OBJECT
+
 """
 Represents an [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601)-encoded date string.
 For example, September 7, 2019 is represented as `"2019-07-16"`.
@@ -108,6 +113,20 @@ The result of API target B.
 """
 input FunctionTargetBResult {
   name: String
+  operations: [Operation!]!
+}
+
+input Operation @oneOf {
+  doThis: This
+  doThat: That
+}
+
+input This {
+  thisField: String!
+}
+
+input That {
+  thatField: Int!
 }
 
 """

example_with_targets/src/main.rs

@@ -23,6 +23,12 @@ fn target_a(_input: schema::target_a::Input) -> Result<schema::FunctionTargetARe
 fn target_b(input: schema::target_b::Input) -> Result<schema::FunctionTargetBResult> {
     Ok(schema::FunctionTargetBResult {
         name: Some(format!("new name: \"{}\"", input.id())),
+        operations: vec![
+            schema::Operation::DoThis(schema::This {
+                this_field: "this field".to_string(),
+            }),
+            schema::Operation::DoThat(schema::That { that_field: 42 }),
+        ],
     })
 }
 

example_with_targets/src/tests.rs

@@ -31,6 +31,12 @@ fn test_target_b() -> Result<()> {
     )?;
     let expected = crate::schema::FunctionTargetBResult {
         name: Some("new name: \"gid://shopify/Order/1234567890\"".to_string()),
+        operations: vec![
+            crate::schema::Operation::DoThis(crate::schema::This {
+                this_field: "this field".to_string(),
+            }),
+            crate::schema::Operation::DoThat(crate::schema::That { that_field: 42 }),
+        ],
     };
 
     assert_eq!(result, expected);

integration_tests/tests/integration_test.rs

@@ -39,7 +39,19 @@ fn test_example_with_targets_target_b() -> Result<()> {
     assert_eq!(
         output,
         serde_json::json!({
-            "name": "new name: \"gid://shopify/Order/1234567890\""
+            "name": "new name: \"gid://shopify/Order/1234567890\"",
+            "operations": [
+                {
+                    "doThis": {
+                        "thisField": "this field"
+                    }
+                },
+                {
+                    "doThat": {
+                        "thatField": 42
+                    }
+                }
+            ]
         })
     );
     Ok(())

shopify_function_macro/src/lib.rs

@@ -529,7 +529,27 @@ impl CodeGenerator for ShopifyFunctionCodeGenerator {
             }
         };
 
-        vec![serialize_impl]
+        let field_values: Vec<syn::FieldValue> = input_object_type_definition
+            .input_field_definitions()
+            .iter()
+            .map(|ivd| {
+                let field_name_ident = names::field_ident(ivd.name());
+                let field_name_lit_str = syn::LitStr::new(ivd.name(), Span::mixed_site());
+                parse_quote! { #field_name_ident: shopify_function::wasm_api::Deserialize::deserialize(&value.get_obj_prop(#field_name_lit_str))? }
+            })
+            .collect();
+
+        let deserialize_impl = parse_quote! {
+            impl shopify_function::wasm_api::Deserialize for #name_ident {
+                fn deserialize(value: &shopify_function::wasm_api::Value) -> ::std::result::Result<Self, shopify_function::wasm_api::read::Error> {
+                    Ok(Self {
+                        #(#field_values),*
+                    })
+                }
+            }
+        };
+
+        vec![serialize_impl, deserialize_impl]
     }
 
     fn additional_impls_for_one_of_input_object(
@@ -567,7 +587,47 @@ impl CodeGenerator for ShopifyFunctionCodeGenerator {
             }
         };
 
-        vec![serialize_impl]
+        let deserialize_match_arms: Vec<syn::Arm> = input_object_type_definition
+            .input_field_definitions()
+            .iter()
+            .map(|ivd| {
+                let field_name_lit_str = syn::LitStr::new(ivd.name(), Span::mixed_site());
+                let variant_ident = names::enum_variant_ident(ivd.name());
+
+                parse_quote! {
+                    #field_name_lit_str => {
+                        let value = shopify_function::wasm_api::Deserialize::deserialize(&field_value)?;
+                        Ok(Self::#variant_ident(value))
+                    }
+                }
+            })
+            .collect();
+
+        let deserialize_impl = parse_quote! {
+            impl shopify_function::wasm_api::Deserialize for #name_ident {
+                fn deserialize(value: &shopify_function::wasm_api::Value) -> ::std::result::Result<Self, shopify_function::wasm_api::read::Error> {
+                    let Some(obj_len) = value.obj_len() else {
+                        return Err(shopify_function::wasm_api::read::Error::InvalidType);
+                    };
+
+                    if obj_len != 1 {
+                        return Err(shopify_function::wasm_api::read::Error::InvalidType);
+                    }
+
+                    let Some(field_name) = value.get_obj_key_at_index(0) else {
+                        return Err(shopify_function::wasm_api::read::Error::InvalidType);
+                    };
+                    let field_value = value.get_at_index(0);
+
+                    match field_name.as_str() {
+                        #(#deserialize_match_arms)*
+                        _ => Err(shopify_function::wasm_api::read::Error::InvalidType),
+                    }
+                }
+            }
+        };
+
+        vec![serialize_impl, deserialize_impl]
     }
 
     fn attributes_for_enum(