[counter] Add persistent counter sensor (#19746)

tests/components/counter/common.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <limits>
+#include <utility>
+
+#include "esphome/core/helpers.h"
+#include "esphome/components/counter/counter_sensor.h"
+
+namespace esphome::counter::testing {
+
+constexpr int64_t INT64_MAX_VALUE = std::numeric_limits<int64_t>::max();
+constexpr int64_t INT64_MIN_VALUE = std::numeric_limits<int64_t>::min();
+
+/// Stands in for a binary sensor: reports each state to its callbacks.
+struct FakeBinarySource {
+  template<typename F> void add_on_state_callback(F &&callback) { this->callbacks_.add(std::forward<F>(callback)); }
+  void publish(bool state) { this->callbacks_.call(state); }
+  CallbackManager<void(bool)> callbacks_;
+};
+
+// Restore is off so no preference storage is needed.
+class CounterTest : public ::testing::Test {
+ protected:
+  CounterSensor counter_{false, 0};
+};
+
+}  // namespace esphome::counter::testing

tests/components/counter/common.yaml

@@ -0,0 +1,37 @@
+esphome:
+  on_boot:
+    then:
+      - counter.set_value:
+          id: counter_sensor
+          value: 100
+      - counter.increment: counter_sensor
+      - counter.increment:
+          id: counter_sensor
+          value: -5
+      - counter.increment:
+          id: counter_sensor
+          value: !lambda "return 5000000000LL;"
+
+sensor:
+  - platform: counter
+    id: counter_sensor
+    name: Counter
+  - platform: counter
+    id: counter_no_restore
+    name: Counter No Restore
+    restore: false
+    initial_value: 10
+  - platform: template
+    id: source_sensor
+    lambda: return 1.0;
+    update_interval: 1s
+  - platform: counter
+    name: Counter Of Sensor
+    sensor: source_sensor
+  - platform: counter
+    name: Counter Of Binary Sensor
+    binary_sensor: source_binary_sensor
+
+binary_sensor:
+  - platform: template
+    id: source_binary_sensor

tests/components/counter/sensor/test_counter.cpp

@@ -0,0 +1,84 @@
+#include "../common.h"
+
+namespace esphome::counter::testing {
+
+TEST_F(CounterTest, StartsAtZero) {
+  this->counter_.setup();
+  EXPECT_EQ(this->counter_.state, 0.0f);
+}
+
+TEST(CounterInitialValue, PublishedAtSetupWhenNotRestoring) {
+  CounterSensor counter(false, -12);
+  counter.setup();
+  EXPECT_EQ(counter.state, -12.0f);
+  counter.increment();
+  EXPECT_EQ(counter.state, -11.0f);
+}
+
+TEST_F(CounterTest, SetValuePublishesState) {
+  this->counter_.set_value(42);
+  EXPECT_EQ(this->counter_.state, 42.0f);
+}
+
+TEST_F(CounterTest, IncrementDefaultsToOne) {
+  this->counter_.increment();
+  this->counter_.increment();
+  EXPECT_EQ(this->counter_.state, 2.0f);
+}
+
+TEST_F(CounterTest, IncrementAcceptsNegativeAmounts) {
+  this->counter_.set_value(10);
+  this->counter_.increment(-25);
+  EXPECT_EQ(this->counter_.state, -15.0f);
+}
+
+TEST_F(CounterTest, ValueBeyondInt32) {
+  this->counter_.set_value(5000000000LL);
+  this->counter_.increment(5000000000LL);
+  EXPECT_EQ(this->counter_.state, 1.0e10f);
+}
+
+TEST_F(CounterTest, IncrementWrapsAtInt64Limits) {
+  this->counter_.set_value(INT64_MAX_VALUE);
+  this->counter_.increment(1);
+  EXPECT_EQ(this->counter_.state, static_cast<float>(INT64_MIN_VALUE));
+
+  this->counter_.set_value(INT64_MIN_VALUE);
+  this->counter_.increment(-1);
+  EXPECT_EQ(this->counter_.state, static_cast<float>(INT64_MAX_VALUE));
+}
+
+TEST_F(CounterTest, CountsEachPublishFromSource) {
+  sensor::Sensor source;
+  this->counter_.count_updates_from(&source);
+
+  // The counted value is unrelated to what the source publishes.
+  source.publish_state(10.0f);
+  source.publish_state(10.0f);
+  source.publish_state(-3.5f);
+  EXPECT_EQ(this->counter_.state, 3.0f);
+}
+
+TEST_F(CounterTest, SourceUpdatesAddToCurrentValue) {
+  sensor::Sensor source;
+  this->counter_.count_updates_from(&source);
+
+  this->counter_.set_value(100);
+  source.publish_state(1.0f);
+  EXPECT_EQ(this->counter_.state, 101.0f);
+}
+
+TEST_F(CounterTest, CountsOnlyTrueFromBinarySource) {
+  FakeBinarySource source;
+  this->counter_.count_true_from(&source);
+
+  source.publish(true);
+  source.publish(false);
+  EXPECT_EQ(this->counter_.state, 1.0f);
+  source.publish(true);
+  source.publish(false);
+  source.publish(false);
+  EXPECT_EQ(this->counter_.state, 2.0f);
+}
+
+}  // namespace esphome::counter::testing

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

@@ -0,0 +1,2 @@
+packages:
+  counter: !include common.yaml

tests/components/counter/validate.esp32-idf.yaml

@@ -0,0 +1,12 @@
+packages:
+  counter: !include common.yaml
+
+esphome:
+  on_shutdown:
+    then:
+      - counter.set_value:
+          id: counter_no_restore
+          value: -9223372036854775807
+      - counter.increment:
+          id: counter_no_restore
+          value: 9223372036854775807