[api] Fall back to owning types for service array args used after a delay (#16140)

esphome/components/api/__init__.py

@@ -72,17 +72,35 @@ APIUnregisterServiceCallAction = api_ns.class_(
 
 UserServiceTrigger = api_ns.class_("UserServiceTrigger", automation.Trigger)
 ListEntitiesServicesArgument = api_ns.class_("ListEntitiesServicesArgument")
-SERVICE_ARG_NATIVE_TYPES: dict[str, MockObj] = {
+# Owning element type for each YAML service variable type.  Used to derive both
+# the zero-copy native types and the owning fallback types below.
+_SERVICE_ARG_SCALAR_TYPES: dict[str, MockObj] = {
     "bool": cg.bool_,
     "int": cg.int32,
     "float": cg.float_,
+    "string": cg.std_string,
+}
+SERVICE_ARG_NATIVE_TYPES: dict[str, MockObj] = {
+    # Scalars are passed by value; string uses a non-owning view into rx_buf_.
+    **_SERVICE_ARG_SCALAR_TYPES,
     "string": cg.StringRef,
-    "bool[]": cg.FixedVector.template(cg.bool_).operator("const").operator("ref"),
-    "int[]": cg.FixedVector.template(cg.int32).operator("const").operator("ref"),
-    "float[]": cg.FixedVector.template(cg.float_).operator("const").operator("ref"),
-    "string[]": cg.FixedVector.template(cg.std_string)
-    .operator("const")
-    .operator("ref"),
+    # Arrays are passed as non-owning const references into rx_buf_.
+    **{
+        f"{name}[]": cg.FixedVector.template(t).operator("const").operator("ref")
+        for name, t in _SERVICE_ARG_SCALAR_TYPES.items()
+    },
+}
+# Owning fallback types used when the action chain contains non-synchronous actions
+# (delay, wait_until, script.wait, etc.).  The default non-owning types reference
+# storage in the receive buffer, which is reused once the synchronous portion of
+# the chain returns.  FixedVector is also non-copyable, so the deferred lambda
+# capture in DelayAction::play_complex would fail to compile.
+SERVICE_ARG_FALLBACK_TYPES: dict[str, MockObj] = {
+    "string": cg.std_string,
+    **{
+        f"{name}[]": cg.std_vector.template(t)
+        for name, t in _SERVICE_ARG_SCALAR_TYPES.items()
+    },
 }
 CONF_ENCRYPTION = "encryption"
 CONF_BATCH_DELAY = "batch_delay"
@@ -382,17 +400,20 @@ async def to_code(config: ConfigType) -> None:
                     func_args.append((cg.bool_, "return_response"))
 
             # Check if action chain has non-synchronous actions that would make
-            # non-owning StringRef dangle (rx_buf_ reused after delay)
+            # non-owning args (StringRef, const FixedVector&) dangle once the
+            # rx_buf_ is reused after a delay/wait_until/script.wait/etc.  The
+            # FixedVector references would also fail to compile because they
+            # are non-copyable and DelayAction captures args by value.
             has_non_synchronous = automation.has_non_synchronous_actions(
                 conf.get(CONF_THEN, [])
             )
 
             service_arg_names: list[str] = []
             for name, var_ in conf[CONF_VARIABLES].items():
-                native = SERVICE_ARG_NATIVE_TYPES[var_]
-                # Fall back to std::string for string args if non-synchronous actions exist
-                if has_non_synchronous and native is cg.StringRef:
-                    native = cg.std_string
+                if has_non_synchronous and var_ in SERVICE_ARG_FALLBACK_TYPES:
+                    native = SERVICE_ARG_FALLBACK_TYPES[var_]
+                else:
+                    native = SERVICE_ARG_NATIVE_TYPES[var_]
                 service_template_args.append(native)
                 func_args.append((native, name))
                 service_arg_names.append(name)

tests/components/api/common-base.yaml

@@ -91,6 +91,24 @@ api:
               - float_arr.size()
               - string_arr[0].c_str()
               - string_arr.size()
+    # Test array + string args used after a non-synchronous action (delay).
+    # The default non-owning types (StringRef, const FixedVector&) would
+    # dangle once rx_buf_ is reused, and FixedVector is non-copyable so
+    # DelayAction's lambda capture would fail to compile.  The api codegen
+    # must fall back to owning std::string / std::vector here.
+    - action: array_with_delay
+      variables:
+        name: string
+        int_arr: int[]
+        string_arr: string[]
+      then:
+        - delay: 20ms
+        - logger.log:
+            format: "Delayed: %s (%u ints, %u strings)"
+            args:
+              - name.c_str()
+              - int_arr.size()
+              - string_arr.size()
     # Test ContinuationAction (IfAction with then/else branches)
     - action: test_if_action
       variables: