Fix method meta error in wasm build

extension/wasm/test/CMakeLists.txt

@@ -11,6 +11,13 @@
 
 set(MODELS_DIR ${CMAKE_CURRENT_BINARY_DIR}/models/)
 
+add_custom_command(
+  OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/models/test.pte
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../..
+  COMMAND python3 -m extension.wasm.test.test_model
+          ${CMAKE_CURRENT_BINARY_DIR}/models/test.pte
+)
+
 add_custom_command(
   OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/models/add_mul.pte
          ${CMAKE_CURRENT_BINARY_DIR}/models/add.pte
@@ -23,8 +30,9 @@ add_custom_command(
 )
 
 add_custom_target(
-  executorch_wasm_test_models DEPENDS ${MODELS_DIR}/add_mul.pte
-                                      ${MODELS_DIR}/add.pte
+  executorch_wasm_test_models
+  DEPENDS ${MODELS_DIR}/add_mul.pte ${MODELS_DIR}/add.pte
+          ${MODELS_DIR}/test.pte
 )
 
 add_custom_command(

extension/wasm/test/test_model.py

@@ -0,0 +1,34 @@
+import sys
+
+import torch
+from executorch.exir import to_edge_transform_and_lower
+from torch.export import export
+
+
+class IndexModel(torch.nn.Module):
+    def forward(self, x, n):
+        return x[n]
+
+
+class AddAllModel(torch.nn.Module):
+    def forward(self, x, n):
+        return x, n, x + n
+
+
+if __name__ == "__main__":
+    output_filepath = sys.argv[1] if len(sys.argv) > 1 else "test.pte"
+    indexModel = IndexModel().eval()
+    addAllModel = AddAllModel().eval()
+
+    exported_index = export(indexModel, (torch.randn([3]), 1))
+    exported_add_all = export(addAllModel, (torch.randn([2, 2]), 1))
+    edge = to_edge_transform_and_lower(
+        {
+            "forward": exported_index,
+            "index": exported_index,
+            "add_all": exported_add_all,
+        }
+    )
+    et = edge.to_executorch()
+    with open(output_filepath, "wb") as file:
+        file.write(et.buffer)

extension/wasm/test/unittests.js

@@ -105,6 +105,13 @@ describe("Module", () => {
         module.delete();
     });
 
+    test("multiple methods", () => {
+        const module = et.Module.load("test.pte");
+        const methods = module.getMethods();
+        expect(methods).toEqual(expect.arrayContaining(["forward", "index", "add_all"]));
+        module.delete();
+    });
+
     test("loadMethod forward", () => {
         const module = et.Module.load("add.pte");
         expect(() => module.loadMethod("forward")).not.toThrow();
@@ -224,6 +231,25 @@ describe("Module", () => {
                 });
                 module.delete();
             });
+
+            test("non-tensor in input", () => {
+                const module = et.Module.load("test.pte");
+                const methodMeta = module.getMethodMeta("add_all");
+                expect(methodMeta.inputTags).toEqual([et.Tag.Tensor, et.Tag.Int]);
+                expect(methodMeta.inputTensorMeta[0]).not.toBeUndefined();
+                expect(methodMeta.inputTensorMeta[1]).toBeUndefined();
+                module.delete();
+            });
+
+            test("non-tensor in output", () => {
+                const module = et.Module.load("test.pte");
+                const methodMeta = module.getMethodMeta("add_all");
+                expect(methodMeta.outputTags).toEqual([et.Tag.Tensor, et.Tag.Int, et.Tag.Tensor]);
+                expect(methodMeta.outputTensorMeta[0]).not.toBeUndefined();
+                expect(methodMeta.outputTensorMeta[1]).toBeUndefined();
+                expect(methodMeta.outputTensorMeta[2]).not.toBeUndefined();
+                module.delete();
+            });
         });
     });
 

extension/wasm/wasm_bindings.cpp

@@ -475,16 +475,26 @@ struct ET_EXPERIMENTAL JsMethodMeta {
         val::array(),
         meta.num_instructions()};
     for (int i = 0; i < meta.num_inputs(); i++) {
-      js_array_push(new_meta.input_tags, meta.input_tag(i).get());
-      js_array_push(
-          new_meta.input_tensor_meta,
-          JsTensorInfo::from_tensor_info(meta.input_tensor_meta(i).get()));
+      Tag tag = meta.input_tag(i).get();
+      js_array_push(new_meta.input_tags, tag);
+      if (tag == Tag::Tensor) {
+        js_array_push(
+            new_meta.input_tensor_meta,
+            JsTensorInfo::from_tensor_info(meta.input_tensor_meta(i).get()));
+      } else {
+        js_array_push(new_meta.input_tensor_meta, val::undefined());
+      }
     }
     for (int i = 0; i < meta.num_outputs(); i++) {
-      js_array_push(new_meta.output_tags, meta.output_tag(i).get());
-      js_array_push(
-          new_meta.output_tensor_meta,
-          JsTensorInfo::from_tensor_info(meta.output_tensor_meta(i).get()));
+      Tag tag = meta.output_tag(i).get();
+      js_array_push(new_meta.output_tags, tag);
+      if (tag == Tag::Tensor) {
+        js_array_push(
+            new_meta.output_tensor_meta,
+            JsTensorInfo::from_tensor_info(meta.output_tensor_meta(i).get()));
+      } else {
+        js_array_push(new_meta.output_tensor_meta, val::undefined());
+      }
     }
     for (int i = 0; i < meta.num_attributes(); i++) {
       js_array_push(