raise error when trying to save an etrecord missing essential info

as title

Differential Revision: [D79687142](https://our.internmc.facebook.com/intern/diff/D79687142/)

[ghstack-poisoned]

Author: Gasoonjia

devtools/etrecord/_etrecord.py

@@ -85,11 +85,19 @@ def save(self, path: Union[str, os.PathLike, BinaryIO, IO[bytes]]) -> None:
 
         Args:
             path: Path where the ETRecord file will be saved to.
+
+        Raises:
+            RuntimeError: If the ETRecord does not contain essential information for Inpector.
         """
         if isinstance(path, (str, os.PathLike)):
             # pyre-ignore[6]: In call `os.fspath`, for 1st positional argument, expected `str` but got `Union[PathLike[typing.Any], str]`
             path = os.fspath(path)
 
+        if not (self.edge_dialect_program and self.graph_map and self._debug_handle_map):
+            raise RuntimeError(
+                "ETRecord must contain edge dialect program, graph map, and debug handle map to be saved."
+            )
+
         etrecord_zip = ZipFile(path, "w")
 
         try:

devtools/etrecord/tests/etrecord_test.py

@@ -1545,3 +1545,32 @@ def test_update_apis_and_save_parse(self):
                 custom_outputs["forward"], parsed_etrecord._reference_outputs["forward"]
             ):
                 self.assertTrue(torch.equal(expected[0], actual[0]))
+
+    def test_save_missing_essential_info(self):
+        def expected_runtime_error(etrecord, etrecord_path):
+            with self.assertRaises(RuntimeError) as context:
+                etrecord.save(etrecord_path)
+
+            self.assertIn(
+                "ETRecord must contain edge dialect program, graph map, and debug handle map to be saved",
+                str(context.exception),
+            )
+
+        """Test that save raises RuntimeError when essential info is missing."""
+        _, edge_output, et_output = self.get_test_model()
+
+        etrecord = ETRecord()
+
+        with tempfile.TemporaryDirectory() as tmpdirname:
+            etrecord_path = tmpdirname + "/etrecord_no_edge.bin"
+
+            expected_runtime_error(etrecord, etrecord_path)
+            etrecord.add_edge_dialect_program(edge_output)
+
+            # Should raise runtime error due to  missing executorch program related info
+            expected_runtime_error(etrecord, etrecord_path)
+
+            etrecord.add_executorch_program(et_output)
+
+            # All essential components are now present, so save should succeed
+            etrecord.save(etrecord_path)