[tests] Add test_display component to free touchscreen tests from display pins (#17540)

tests/components/gsl3670/test.esp32-s3-idf.yaml

@@ -1,32 +1,20 @@
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp32-s3-idf.yaml
-  spi: !include ../../test_build_components/common/spi/esp32-s3-idf.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
 
 xl9535:
   id: expander
 
-display:
-  - platform: mipi_spi
-    id: gsl3670_display
-    spi_id: spi_bus
-    model: t-display-s3-pro
-    # The model's default DC pin (GPIO9) clashes with the shared i2c bus SCL
-    # pin, so override it onto a free pin for this test.
-    dc_pin: GPIO5
-
-psram:
-  mode: quad
-
 touchscreen:
   # Firmware downloaded from the model's default release URL and cached.
   - platform: gsl3670
     model: seeed-reterminal-d1001
-    display: gsl3670_display
+    display: test_display_screen
     interrupt_pin: 18
   # Explicit firmware URL + SHA-256 override.
   - platform: gsl3670
     model: seeed-reterminal-d1001
-    display: gsl3670_display
+    display: test_display_screen
     reset_pin: 10
     interrupt_pin: 11
     firmware:

tests/components/gt911/common.yaml

@@ -1,19 +1,8 @@
-display:
-  - platform: ssd1306_i2c
-    i2c_id: i2c_bus
-    id: gt911_ssd1306_i2c_display
-    model: SSD1306_128X64
-    reset_pin: ${display_reset_pin}
-    pages:
-      - id: gt911_page1
-        lambda: |-
-          it.rectangle(0, 0, it.get_width(), it.get_height());
-
 touchscreen:
   - platform: gt911
     i2c_id: i2c_bus
     id: gt911_touchscreen
-    display: gt911_ssd1306_i2c_display
+    display: test_display_screen
     interrupt_pin: ${interrupt_pin}
     reset_pin: ${reset_pin}
 

tests/components/gt911/test.esp32-idf.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  display_reset_pin: "10"
   interrupt_pin: "20"
   reset_pin: "21"
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp32-idf.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  gt911: !include common.yaml

tests/components/gt911/test.esp8266-ard.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  display_reset_pin: "10"
   interrupt_pin: "12"
   reset_pin: "13"
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp8266-ard.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  gt911: !include common.yaml

tests/components/gt911/test.rp2040-ard.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  display_reset_pin: "10"
   interrupt_pin: "20"
   reset_pin: "21"
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/rp2040-ard.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  gt911: !include common.yaml

tests/components/test_display/common.yaml

@@ -0,0 +1,13 @@
+# The test_display platform (and its external_components entry) is provided by
+# the shared package included from the test.*.yaml files. These extra instances
+# exercise the remaining `dimensions` code paths: the width/height map form and
+# the default when omitted. The package's own `test_display_screen` covers the
+# "WIDTHxHEIGHT" string form.
+display:
+  - platform: test_display
+    id: test_display_wh_dimensions
+    dimensions:
+      width: 320
+      height: 240
+  - platform: test_display
+    id: test_display_default_dimensions

tests/components/test_display/components/test_display/display.py

@@ -0,0 +1,36 @@
+import esphome.codegen as cg
+from esphome.components import display
+import esphome.config_validation as cv
+from esphome.const import CONF_DIMENSIONS, CONF_HEIGHT, CONF_ID, CONF_WIDTH
+from esphome.core import CoroPriority, coroutine_with_priority
+
+test_display_ns = cg.esphome_ns.namespace("test_display")
+TestDisplay = test_display_ns.class_("TestDisplay", display.Display)
+
+CONFIG_SCHEMA = display.FULL_DISPLAY_SCHEMA.extend(
+    {
+        cv.GenerateID(): cv.declare_id(TestDisplay),
+        cv.Optional(CONF_DIMENSIONS, default="100x100"): cv.Any(
+            cv.dimensions,
+            cv.Schema(
+                {
+                    cv.Required(CONF_WIDTH): cv.int_,
+                    cv.Required(CONF_HEIGHT): cv.int_,
+                }
+            ),
+        ),
+    }
+)
+
+
+@coroutine_with_priority(CoroPriority.CORE)
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await display.register_display(var, config)
+
+    dimensions = config[CONF_DIMENSIONS]
+    if isinstance(dimensions, dict):
+        width, height = dimensions[CONF_WIDTH], dimensions[CONF_HEIGHT]
+    else:
+        width, height = dimensions
+    cg.add(var.set_dimensions(width, height))

tests/components/test_display/components/test_display/test_display.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "esphome/components/display/display.h"
+#include "esphome/core/color.h"
+
+namespace esphome::test_display {
+
+/** A no-op display that draws nothing and uses no pins.
+ *
+ * It exists purely to satisfy components that require a display (for example
+ * touchscreens, which read the display dimensions) in configurations - most
+ * notably YAML build tests - where a real display driver would only get in the
+ * way by occupying GPIO pins and pulling in bus dependencies.
+ */
+class TestDisplay : public display::Display {
+ public:
+  void update() override { this->do_update_(); }
+
+  void set_dimensions(int width, int height) {
+    this->width_ = width;
+    this->height_ = height;
+  }
+
+  display::DisplayType get_display_type() override { return display::DisplayType::DISPLAY_TYPE_COLOR; }
+
+  void draw_pixel_at(int x, int y, Color color) override {}
+
+ protected:
+  int get_width_internal() override { return this->width_; }
+  int get_height_internal() override { return this->height_; }
+
+  int width_{0};
+  int height_{0};
+};
+
+}  // namespace esphome::test_display

tests/components/test_display/test.esp32-idf.yaml

@@ -0,0 +1,3 @@
+packages:
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  test_display_extra: !include common.yaml

tests/components/test_display/test.esp8266-ard.yaml

@@ -0,0 +1,3 @@
+packages:
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  test_display_extra: !include common.yaml

tests/components/test_display/test.rp2040-ard.yaml

@@ -0,0 +1,3 @@
+packages:
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  test_display_extra: !include common.yaml

tests/components/tt21100/common.yaml

@@ -1,19 +1,8 @@
-display:
-  - platform: ssd1306_i2c
-    i2c_id: i2c_bus
-    id: tt21100_ssd1306_i2c_display
-    model: SSD1306_128X64
-    reset_pin: ${disp_reset_pin}
-    pages:
-      - id: tt21100_page1
-        lambda: |-
-          it.rectangle(0, 0, it.get_width(), it.get_height());
-
 touchscreen:
   - platform: tt21100
     i2c_id: i2c_bus
     id: tt21100_touchscreen
-    display: tt21100_ssd1306_i2c_display
+    display: test_display_screen
     interrupt_pin: ${interrupt_pin}
     reset_pin: ${reset_pin}
 

tests/components/tt21100/test.esp32-idf.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  disp_reset_pin: GPIO12
   interrupt_pin: GPIO15
   reset_pin: GPIO4
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp32-idf.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  tt21100: !include common.yaml

tests/components/tt21100/test.esp8266-ard.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  disp_reset_pin: GPIO0
   interrupt_pin: GPIO15
   reset_pin: GPIO16
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/esp8266-ard.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  tt21100: !include common.yaml

tests/components/tt21100/test.rp2040-ard.yaml

@@ -1,9 +1,8 @@
 substitutions:
-  disp_reset_pin: GPIO10
   interrupt_pin: GPIO2
   reset_pin: GPIO3
 
 packages:
   i2c: !include ../../test_build_components/common/i2c/rp2040-ard.yaml
-
-<<: !include common.yaml
+  test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+  tt21100: !include common.yaml

tests/test_build_components/common/test_display/test_display.yaml

@@ -0,0 +1,26 @@
+# Shared "test display" package for component tests.
+#
+# Provides a no-op display (id: test_display_screen) that uses no pins and no
+# bus, so tests that only need a display to exist -- touchscreens especially --
+# don't have to instantiate a real driver and fight it over GPIOs. Include it
+# like a common bus package; the consuming test does NOT need to declare
+# external_components itself:
+#
+#   packages:
+#     test_display: !include ../../test_build_components/common/test_display/test_display.yaml
+#
+# then point the touchscreen (or other display consumer) at `test_display_screen`.
+#
+# The test_display platform lives at tests/components/test_display/components/ and
+# is loaded via external_components. The source path is written relative to the
+# build directory (tests/test_build_components/build/), which every test --
+# standalone or grouped -- is generated into, so this always resolves to the
+# component under tests/components/test_display/.
+external_components:
+  - source: ../../components/test_display/components
+    components: [test_display]
+
+display:
+  - platform: test_display
+    id: test_display_screen
+    dimensions: 240x320