[nextion] Keep add_waveform_data() available without a waveform sensor (#19590)

esphome/components/nextion/nextion.h

@@ -614,7 +614,6 @@ class Nextion final : public NextionBase, public PollingComponent, public uart::
    */
   void disable_component_touch(const char *component);
 
-#ifdef USE_NEXTION_WAVEFORM
   /**
    * Add waveform data to a waveform component
    * @param component_id The integer component id.
@@ -624,7 +623,6 @@ class Nextion final : public NextionBase, public PollingComponent, public uart::
   void add_waveform_data(uint8_t component_id, uint8_t channel_number, uint8_t value);
 
   void open_waveform_channel(uint8_t component_id, uint8_t channel_number, uint8_t value);
-#endif  // USE_NEXTION_WAVEFORM
 
   /**
    * Display a picture at coordinates.

esphome/components/nextion/nextion_commands.cpp

@@ -217,7 +217,6 @@ void Nextion::set_component_value(const char *component, int32_t value) {
   this->add_no_result_to_queue_with_printf_(".val", "%s.val=%" PRId32, component, value);
 }
 
-#ifdef USE_NEXTION_WAVEFORM
 void Nextion::add_waveform_data(uint8_t component_id, uint8_t channel_number, uint8_t value) {
   this->add_no_result_to_queue_with_printf_("add", "add %" PRIu8 ",%" PRIu8 ",%" PRIu8, component_id, channel_number,
                                             value);
@@ -227,7 +226,6 @@ void Nextion::open_waveform_channel(uint8_t component_id, uint8_t channel_number
   this->add_no_result_to_queue_with_printf_("addt", "addt %" PRIu8 ",%" PRIu8 ",%" PRIu8, component_id, channel_number,
                                             value);
 }
-#endif  // USE_NEXTION_WAVEFORM
 
 void Nextion::set_component_coordinates(const char *component, uint16_t x, uint16_t y) {
   this->add_no_result_to_queue_with_printf_(".xcen", "%s.xcen=%" PRIu16, component, x);

tests/components/nextion/common_waveform_lambda.yaml

@@ -0,0 +1,8 @@
+# Waveform commands from a lambda with no waveform sensor configured, so
+# USE_NEXTION_WAVEFORM is not defined.
+display:
+  - platform: nextion
+    id: main_lcd
+    lambda: |-
+      id(main_lcd).open_waveform_channel(37, 0, 10);
+      id(main_lcd).add_waveform_data(37, 0, 42);

tests/components/nextion/test-waveform-lambda.esp32-idf.yaml

@@ -0,0 +1,3 @@
+packages:
+  uart: !include ../../test_build_components/common/uart/esp32-idf.yaml
+  waveform_lambda: !include common_waveform_lambda.yaml