feat: export now supports return type closes #968

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## unreleased
 
+### Added
+
+- **aiken-project**: `export` output now supports the functions `return_type`. @rvcas
+
 ### Changed
 
 - **aiken-project**: The `aiken.toml` file no longer supports `v1` and `v2` for the plutus version field. @rvcas

crates/aiken-project/src/export.rs

@@ -7,7 +7,11 @@ use crate::{
     },
     module::{CheckedModule, CheckedModules},
 };
-use aiken_lang::{ast::TypedFunction, gen_uplc::CodeGenerator, plutus_version::PlutusVersion};
+use aiken_lang::{
+    ast::{ArgName, Span, TypedArg, TypedFunction},
+    gen_uplc::CodeGenerator,
+    plutus_version::PlutusVersion,
+};
 use miette::NamedSource;
 use uplc::ast::SerializableProgram;
 
@@ -22,6 +26,8 @@ pub struct Export {
     #[serde(default)]
     pub parameters: Vec<Parameter>,
 
+    pub return_type: Parameter,
+
     #[serde(flatten)]
     pub program: SerializableProgram,
 
@@ -64,6 +70,38 @@ impl Export {
             })
             .collect::<Result<_, _>>()?;
 
+        let return_type = Annotated::from_type(
+            modules.into(),
+            blueprint::validator::tipo_or_annotation(
+                module,
+                &TypedArg {
+                    arg_name: ArgName::Discarded {
+                        name: "".to_string(),
+                        label: "".to_string(),
+                        location: Span::empty(),
+                    },
+                    location: Span::empty(),
+                    annotation: func.return_annotation.clone(),
+                    doc: None,
+                    is_validator_param: false,
+                    tipo: func.return_type.clone(),
+                },
+            ),
+            &mut definitions,
+        )
+        .map(|schema| Parameter {
+            title: Some("return_type".to_string()),
+            schema: Declaration::Referenced(schema),
+        })
+        .map_err(|error| blueprint::Error::Schema {
+            error,
+            location: func.location,
+            source_code: NamedSource::new(
+                module.input_path.display().to_string(),
+                module.code.clone(),
+            ),
+        })?;
+
         let program = generator
             .generate_raw(&func.body, &func.arguments, &module.name)
             .to_debruijn()
@@ -79,6 +117,7 @@ impl Export {
             name: format!("{}.{}", &module.name, &func.name),
             doc: func.doc.clone(),
             parameters,
+            return_type,
             program,
             definitions,
         })