fix(bindgen): implementation of flat lower own

Author: vados-cosmonic

crates/js-component-bindgen/src/intrinsics/lower.rs

@@ -924,17 +924,31 @@ impl LowerIntrinsic {
                 ));
             }
 
-            // TODO: implement lower flat own
             Self::LowerFlatOwn => {
                 let debug_log_fn = Intrinsic::DebugLog.name();
                 let lower_flat_own_fn = self.name();
+
                 output.push_str(&format!(
-                    "
-                    function {lower_flat_own_fn}(ctx) {{
-                        {debug_log_fn}('[{lower_flat_own_fn}()] args', {{ ctx }});
-                        throw new Error('flat lower for owned resources not yet implemented!');
-                    }}
-                "
+                    r#"
+                      function {lower_flat_own_fn}(meta) {{
+                          const {{ lowerFn, componentIdx }} = meta;
+
+                          return function {lower_flat_own_fn}Inner(ctx) {{
+                              {debug_log_fn}('[{lower_flat_own_fn}()] args', {{ ctx }});
+                              const {{ createFn }} = ctx;
+
+                              if (ctx.componentIdx !== componentIdx) {{
+                                  throw new Error(`component index mismatch (expected [${{componentIdx}}], lift called from [${{ctx.componentIdx}}])`);
+                              }}
+
+                              console.log("PARAMS?", [...arguments]);
+
+                              const obj = ctx.vals[0];
+                              if (obj === undefined || obj === null) {{ throw new Error('missing resource'); }}
+                              lowerFn(obj);
+                          }};
+                      }}
+                    "#
                 ));
             }
 

crates/js-component-bindgen/src/intrinsics/resource.rs

@@ -61,6 +61,9 @@ pub enum ResourceIntrinsic {
     ResourceTransferBorrowValidLifting,
     ResourceTransferOwn,
     CurResourceBorrows,
+
+    /// Monotonically increasing ID that is used for lowered resource reps
+    LoweredResourceRepId,
 }
 
 impl ResourceIntrinsic {
@@ -83,6 +86,7 @@ impl ResourceIntrinsic {
             Self::ResourceTransferBorrowValidLifting.name(),
             Self::ResourceTransferOwn.name(),
             Self::CurResourceBorrows.name(),
+            Self::LoweredResourceRepId.name(),
         ]
     }
 
@@ -100,6 +104,7 @@ impl ResourceIntrinsic {
             Self::ResourceTransferBorrowValidLifting => "resourceTransferBorrowValidLifting",
             Self::ResourceTransferOwn => "resourceTransferOwn",
             Self::CurResourceBorrows => "curResourceBorrows",
+            Self::LoweredResourceRepId => "LOWERED_RESOURCE_REP",
         }
     }
 
@@ -252,6 +257,11 @@ impl ResourceIntrinsic {
                 let name = self.name();
                 output.push_str(&format!("let {name} = [];"));
             }
+
+            Self::LoweredResourceRepId => {
+                let name = self.name();
+                output.push_str(&format!("const {name} = 1;"));
+            }
         }
     }
 }