Handle struct returns with one primitive field

core/src/hir/type_context.rs

@@ -103,7 +103,7 @@ impl TypeContext {
             )
     }
 
-    pub fn all_traits<'tcx>(&'tcx self) -> impl Iterator<Item = (TraitId, &TraitDef)> {
+    pub fn all_traits<'tcx>(&'tcx self) -> impl Iterator<Item = (TraitId, &'tcx TraitDef)> {
         self.traits
             .iter()
             .enumerate()
@@ -203,7 +203,7 @@ impl TypeContext {
     pub(super) fn from_ast_without_validation<'ast>(
         env: &'ast Env,
         attr_validator: impl AttributeValidator + 'static,
-    ) -> Result<(LoweringContext, Self), Vec<ErrorAndContext>> {
+    ) -> Result<(LoweringContext<'ast>, Self), Vec<ErrorAndContext>> {
         let mut ast_out_structs = SmallVec::<[_; 16]>::new();
         let mut ast_structs = SmallVec::<[_; 16]>::new();
         let mut ast_opaques = SmallVec::<[_; 16]>::new();

feature_tests/js/test/struct-ts.mjs

@@ -1,5 +1,5 @@
 import test from 'ava';
-import { MyEnum, MyStruct } from "diplomat-wasm-js-feature-tests";
+import { MyEnum, MyStruct, CyclicStructB } from "diplomat-wasm-js-feature-tests";
 test("Verify invariants of struct", t => {
     const s = MyStruct.new_();
     t.is(s.a, 17);
@@ -23,3 +23,11 @@ test("Test struct creation", t => {
     });
     t.is(s.intoA(), 17);
 });
+test("Function Returning Nested Struct of One Field", t => {
+    const a = CyclicStructB.getA();
+    t.is(a.cyclicOut(), "0");
+});
+test("Function De-Referencing Nested Struct of One Primitive", t => {
+    const a = CyclicStructB.getAOption();
+    t.is(a.cyclicOut(), "0");
+});

feature_tests/js/test/struct-ts.mts

@@ -1,5 +1,5 @@
 import test from 'ava';
-import { MyEnum, MyStruct } from "diplomat-wasm-js-feature-tests";
+import { MyEnum, MyStruct, CyclicStructB } from "diplomat-wasm-js-feature-tests";
 
 test("Verify invariants of struct", t => {
     const s = MyStruct.new_();
@@ -24,4 +24,14 @@ test("Test struct creation", t => {
         g: MyEnum.B
     });
     t.is(s.intoA(), 17);
+});
+
+test("Function Returning Nested Struct of One Field", t => {
+    const a = CyclicStructB.getA();
+    t.is(a.cyclicOut(), "0");
+});
+
+test("Function De-Referencing Nested Struct of One Primitive", t => {
+    const a = CyclicStructB.getAOption();
+    t.is(a.cyclicOut(), "0");
 });

feature_tests/js/test/struct.mjs

@@ -1,5 +1,5 @@
 import test from 'ava';
-import { MyEnum, MyStruct, ScalarPairWithPadding, BigStructWithStuff } from "diplomat-wasm-js-feature-tests";
+import { MyEnum, MyStruct, ScalarPairWithPadding, BigStructWithStuff, CyclicStructB } from "diplomat-wasm-js-feature-tests";
 
 test("Verify invariants of struct", t => {
     const s = MyStruct.new_("hello");
@@ -46,3 +46,13 @@ test("Test struct layout: complex struct with multiple padding types and contain
     s.assertValue(853);
     t.is(true, true); // Ava doesn't like tests without assertions
 });
+
+test("Function Returning Nested Struct of One Primitive", t => {
+    const a = CyclicStructB.getA();
+    t.is(a.cyclicOut(), "0");
+});
+
+test("Function De-Referencing Nested Struct of One Primitive", t => {
+    const a = CyclicStructB.getAOption();
+    t.is(a.cyclicOut(), "0");
+});

feature_tests/src/structs.rs

@@ -228,6 +228,10 @@ pub mod ffi {
         pub fn get_a() -> CyclicStructA {
             Default::default()
         }
+
+        pub fn get_a_option() -> Option<CyclicStructA> {
+            Some(Default::default())
+        }
     }
 
     impl CyclicStructC {