to_value proc macro

terraform-provider-example/src/main.rs

@@ -1,4 +1,4 @@
-use std::collections::{BTreeMap, HashMap};
+use std::collections::HashMap;
 
 use terustform::{
     framework::{
@@ -6,7 +6,7 @@ use terustform::{
         provider::Provider,
         AttrPath, DResult, Diagnostics, StringValue, ValueModel,
     },
-    values::{Value, ValueKind},
+    values::Value,
 };
 
 #[tokio::main]
@@ -28,6 +28,13 @@ impl Provider for ExampleProvider {
 
 struct ExampleDataSource {}
 
+#[derive(terustform::DataSourceModel)]
+struct ExampleDataSourceModel {
+    name: StringValue,
+    meow: StringValue,
+    id: StringValue,
+}
+
 impl DataSource for ExampleDataSource {
     fn name(&self, provider_name: &str) -> String {
         format!("{provider_name}_kitty")
@@ -66,7 +73,7 @@ impl DataSource for ExampleDataSource {
     }
 
     fn read(&self, config: Value) -> DResult<Value> {
-        let model = ExampleDataSourceModel::from_value(config, &AttrPath::root())?;
+        let mut model = ExampleDataSourceModel::from_value(config, &AttrPath::root())?;
 
         let StringValue::Known(name_str) = &model.name else {
             return Err(Diagnostics::error_string(
@@ -75,23 +82,9 @@ impl DataSource for ExampleDataSource {
         };
         let meow = format!("mrrrrr i am {name_str}");
 
-        Ok(Value::Known(ValueKind::Object(BTreeMap::from([
+        model.meow = StringValue::Known(meow);
-            ("name".to_owned(), model.name.to_value()),
+        model.id = StringValue::Known("0".to_owned());
-            (
+
-                "meow".to_owned(),
+        Ok(model.to_value())
-                Value::Known(ValueKind::String(meow)),
-            ),
-            (
-                "id".to_owned(),
-                Value::Known(ValueKind::String("0".to_owned())),
-            ),
-        ]))))
     }
 }
-
-#[derive(terustform::DataSourceModel)]
-struct ExampleDataSourceModel {
-    name: StringValue,
-    meow: StringValue,
-    id: StringValue,
-}

terustform-macros/src/lib.rs

@@ -30,7 +30,7 @@ fn data_source_model_inner(
         ));
     };
 
-    let terustform = quote!(::terustform::__derive_private);
+    let tf = quote!(::terustform::__derive_private);
 
     let fields = fields
         .named
@@ -44,61 +44,74 @@ fn data_source_model_inner(
         })
         .collect::<Result<Vec<_>, _>>()?;
 
-
     let field_extractions = fields.iter().map(|(name, ty)| {
         let name_str = proc_macro2::Literal::string(&name.to_string());
         quote! {
-            let #terustform::Some(#name) = obj.remove(#name_str) else {
+            let #tf::Some(#name) = obj.remove(#name_str) else {
-                return #terustform::Err(
+                return #tf::Err(
-                    #terustform::Diagnostics::error_string(
+                    #tf::Diagnostics::error_string(
                         format!("Expected property '{}', which was not present", #name_str),
                     ).with_path(path.clone())
                 );
             };
-            let #name = <#ty as #terustform::ValueModel>::from_value(
+            let #name = <#ty as #tf::ValueModel>::from_value(
                 #name,
-                &path.append_attribute_name(#terustform::ToOwned::to_owned(#name_str))
+                &path.append_attribute_name(#tf::ToOwned::to_owned(#name_str))
             )?;
         }
     });
     let constructor_fields = fields.iter().map(|(name, _)| quote! { #name, });
 
+    let to_value_fields = fields.iter().map(|(name, ty)| {
+        let name_str = proc_macro2::Literal::string(&name.to_string());
+
+        quote! { (#name_str, <#ty as #tf::ValueModel>::to_value(self.#name)), }
+    });
+
     let (impl_generics, type_generics, where_clause) = input.generics.split_for_impl();
 
     Ok(quote! {
         #[automatically_derived]
-        impl #impl_generics #terustform::ValueModel
+        impl #impl_generics #tf::ValueModel
             for #struct_name #type_generics #where_clause
         {
-            fn from_value(v: #terustform::Value, path: &#terustform::AttrPath) -> #terustform::DResult<Self> {
+            fn from_value(v: #tf::Value, path: &#tf::AttrPath) -> #tf::DResult<Self> {
                 match v {
-                    #terustform::BaseValue::Unknown => {
+                    #tf::BaseValue::Unknown => {
-                        return #terustform::Err(#terustform::Diagnostics::with_path(
+                        return #tf::Err(#tf::Diagnostics::with_path(
-                            #terustform::Diagnostics::error_string(#terustform::ToOwned::to_owned("Expected object, found unknown value")),
+                            #tf::Diagnostics::error_string(#tf::ToOwned::to_owned("Expected object, found unknown value")),
-                            #terustform::Clone::clone(&path),
+                            #tf::Clone::clone(&path),
                         ));
                     },
-                    #terustform::BaseValue::Null => {
+                    #tf::BaseValue::Null => {
-                        return #terustform::Err(#terustform::Diagnostics::with_path(
+                        return #tf::Err(#tf::Diagnostics::with_path(
-                            #terustform::Diagnostics::error_string(#terustform::ToOwned::to_owned("Expected object, found null value")),
+                            #tf::Diagnostics::error_string(#tf::ToOwned::to_owned("Expected object, found null value")),
-                            #terustform::Clone::clone(&path),
+                            #tf::Clone::clone(&path),
                         ));
                     },
-                    #terustform::BaseValue::Known(#terustform::ValueKind::Object(mut obj)) => {
+                    #tf::BaseValue::Known(#tf::ValueKind::Object(mut obj)) => {
                         #(#field_extractions)*
 
                         Ok(#struct_name {
                             #(#constructor_fields)*
                         })
                     },
-                    #terustform::BaseValue::Known(v) => {
+                    #tf::BaseValue::Known(v) => {
-                        return #terustform::Err(#terustform::Diagnostics::with_path(
+                        return #tf::Err(#tf::Diagnostics::with_path(
-                            #terustform::Diagnostics::error_string(format!("Expected object, found {} value", v.diagnostic_type_str())),
+                            #tf::Diagnostics::error_string(format!("Expected object, found {} value", v.diagnostic_type_str())),
-                            #terustform::Clone::clone(&path),
+                            #tf::Clone::clone(&path),
                         ));
                     },
                 }
             }
+
+            fn to_value(self) -> #tf::Value {
+                #tf::new_object(
+                    [
+                        #(#to_value_fields)*
+                    ]
+                )
+            }
         }
     })
 }

terustform/src/framework/mod.rs

@@ -90,9 +90,7 @@ impl<T> BaseValue<T> {
 pub trait ValueModel: Sized {
     fn from_value(v: Value, path: &AttrPath) -> DResult<Self>;
 
-    fn to_value(self) -> Value {
+    fn to_value(self) -> Value;
-        todo!()
-    }
 }
 
 impl ValueModel for StringValue {

terustform/src/lib.rs

@@ -108,5 +108,11 @@ pub mod __derive_private {
         AttrPath, AttrPathSegment, BaseValue, DResult, Diagnostics, ValueModel,
     };
     pub use crate::values::{Value, ValueKind};
-    pub use {Clone, Result::Err, Option::Some, ToOwned};
+    pub use {Clone, Option::Some, Result::Err, ToOwned};
+
+    pub fn new_object<const N: usize>(elems: [(&str, Value); N]) -> Value {
+        Value::Known(ValueKind::Object(std::collections::BTreeMap::from_iter(
+            elems.into_iter().map(|(k, v)| (k.to_owned(), v)),
+        )))
+    }
 }