Merge remote-tracking branch 'upstream/fix-light-action-trigger-args' into integration

esphome/components/light/automation.h

@@ -36,9 +36,16 @@ template<bool HasTransitionLength, typename... Ts> class ToggleAction : public A
 // plus one parent pointer, regardless of how many fields the user set.
 // Trigger args are forwarded to the apply function so user lambdas
 // (e.g. `brightness: !lambda "return x;"`) keep working.
+//
+// Trigger args are normalized to `const std::remove_cvref_t<Ts> &...` so
+// the codegen can emit a matching parameter list for both the apply lambda
+// and any inner field lambdas without producing invalid C++ source text
+// (e.g. `const T & &` if Ts already carries a reference, or `const const
+// T &` if Ts already carries a const). This keeps trigger args no-copy
+// regardless of whether the trigger supplies `T`, `T &`, or `const T &`.
 template<typename... Ts> class LightControlAction : public Action<Ts...> {
  public:
-  using ApplyFn = void (*)(LightState *, LightCall &, const Ts &...);
+  using ApplyFn = void (*)(LightState *, LightCall &, const std::remove_cvref_t<Ts> &...);
   LightControlAction(LightState *parent, ApplyFn apply) : parent_(parent), apply_(apply) {}
 
   void play(const Ts &...x) override {

esphome/components/light/automation.py

@@ -200,6 +200,15 @@ async def light_control_to_code(config, action_id, template_arg, args):
         (CONF_WARM_WHITE, "set_warm_white", cg.float_),
     )
 
+    # Normalize trigger args to `const std::remove_cvref_t<T> &` so the
+    # apply lambda and any inner field lambdas (generated below via
+    # `process_lambda`) share one parameter spelling that's well-formed for
+    # any T (value, ref, or const-ref). Matches LightControlAction::ApplyFn.
+    normalized_args = [
+        (cg.RawExpression(f"const std::remove_cvref_t<{cg.safe_exp(t)}> &"), n)
+        for t, n in args
+    ]
+
     fwd_args = ", ".join(name for _, name in args)
     body_lines: list[str] = []
 
@@ -208,7 +217,7 @@ async def light_control_to_code(config, action_id, template_arg, args):
             continue
         value = config[conf_key]
         if isinstance(value, Lambda):
-            inner = await cg.process_lambda(value, args, return_type=type_)
+            inner = await cg.process_lambda(value, normalized_args, return_type=type_)
             body_lines.append(f"call.{setter}(({inner})({fwd_args}));")
         else:
             body_lines.append(f"call.{setter}({cg.safe_exp(value)});")
@@ -216,7 +225,7 @@ async def light_control_to_code(config, action_id, template_arg, args):
     if CONF_EFFECT in config:
         if isinstance(config[CONF_EFFECT], Lambda):
             inner_lambda = await cg.process_lambda(
-                config[CONF_EFFECT], args, return_type=cg.std_string
+                config[CONF_EFFECT], normalized_args, return_type=cg.std_string
             )
             body_lines.append(
                 f"{{ auto __effect_s = ({inner_lambda})({fwd_args});\n"
@@ -230,11 +239,10 @@ async def light_control_to_code(config, action_id, template_arg, args):
                 f"call.set_effect(static_cast<uint32_t>({_resolve_effect_index(config)}));"
             )
 
-    # Match LightControlAction::ApplyFn signature: const Ts &... for trigger args.
     apply_args = [
         (LightState.operator("ptr"), "parent"),
         (LightCall.operator("ref"), "call"),
-        *((t.operator("const").operator("ref"), n) for t, n in args),
+        *normalized_args,
     ]
     apply_lambda = LambdaExpression(
         ["\n".join(body_lines)],

tests/components/light/common.yaml

@@ -127,6 +127,21 @@ esphome:
           blue: 0%
           transition_length: 1s
 
+# Exercise light actions inside a trigger with non-empty Ts (number on_value
+# passes float).
+number:
+  - platform: template
+    id: test_number_brightness
+    optimistic: true
+    min_value: 0
+    max_value: 100
+    step: 1
+    on_value:
+      then:
+        - light.turn_on:
+            id: test_monochromatic_light
+            brightness: !lambda "return x / 100.0;"
+
 light:
   - platform: binary
     id: test_binary_light