[gpio_expander] Fix bank caching (#10077)

Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

tests/integration/fixtures/external_components/gpio_expander_test_component/__init__.py

@@ -0,0 +1,25 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.const import CONF_ID
+
+AUTO_LOAD = ["gpio_expander"]
+
+gpio_expander_test_component_ns = cg.esphome_ns.namespace(
+    "gpio_expander_test_component"
+)
+
+GPIOExpanderTestComponent = gpio_expander_test_component_ns.class_(
+    "GPIOExpanderTestComponent", cg.Component
+)
+
+
+CONFIG_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(): cv.declare_id(GPIOExpanderTestComponent),
+    }
+).extend(cv.COMPONENT_SCHEMA)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)

tests/integration/fixtures/external_components/gpio_expander_test_component/gpio_expander_test_component.cpp

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+#include "gpio_expander_test_component.h"
+
+#include "esphome/core/application.h"
+#include "esphome/core/log.h"
+
+namespace esphome::gpio_expander_test_component {
+
+static const char *const TAG = "gpio_expander_test";
+
+void GPIOExpanderTestComponent::setup() {
+  for (uint8_t pin = 0; pin < 32; pin++) {
+    this->digital_read(pin);
+  }
+
+  this->digital_read(3);
+  this->digital_read(3);
+  this->digital_read(4);
+  this->digital_read(3);
+  this->digital_read(10);
+  this->reset_pin_cache_();  // Reset cache to ensure next read is from hardware
+  this->digital_read(15);
+  this->digital_read(14);
+  this->digital_read(14);
+
+  ESP_LOGD(TAG, "DONE");
+}
+
+bool GPIOExpanderTestComponent::digital_read_hw(uint8_t pin) {
+  ESP_LOGD(TAG, "digital_read_hw pin=%d", pin);
+  return true;
+}
+
+bool GPIOExpanderTestComponent::digital_read_cache(uint8_t pin) {
+  ESP_LOGD(TAG, "digital_read_cache pin=%d", pin);
+  return true;
+}
+
+}  // namespace esphome::gpio_expander_test_component

tests/integration/fixtures/external_components/gpio_expander_test_component/gpio_expander_test_component.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "esphome/components/gpio_expander/cached_gpio.h"
+#include "esphome/core/component.h"
+
+namespace esphome::gpio_expander_test_component {
+
+class GPIOExpanderTestComponent : public Component, public esphome::gpio_expander::CachedGpioExpander<uint8_t, 32> {
+ public:
+  void setup() override;
+
+ protected:
+  bool digital_read_hw(uint8_t pin) override;
+  bool digital_read_cache(uint8_t pin) override;
+  void digital_write_hw(uint8_t pin, bool value) override{};
+};
+
+}  // namespace esphome::gpio_expander_test_component

tests/integration/fixtures/gpio_expander_cache.yaml

@@ -0,0 +1,17 @@
+esphome:
+  name: gpio-expander-cache
+host:
+
+logger:
+  level: DEBUG
+
+api:
+
+# External component that uses gpio_expander::CachedGpioExpander
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+    components: [gpio_expander_test_component]
+
+gpio_expander_test_component: