Merge remote-tracking branch 'origin/dev' into ld2412_frame_lengths

# Conflicts:
#	tests/integration/test_uart_mock_ld2412.py

esphome/components/display/__init__.py

@@ -181,16 +181,6 @@ def get_all_display_metadata() -> dict[str, DisplayMetaData]:
     return {id_.id: meta for id_, meta in entries}
 
 
-def config_has_writer(config: ConfigType) -> bool:
-    """Return True when the display config draws anything."""
-    return (
-        config.get(CONF_AUTO_CLEAR_ENABLED) is True
-        or config.get(CONF_PAGES) is not None
-        or config.get(CONF_LAMBDA) is not None
-        or config.get(CONF_SHOW_TEST_CARD) is True
-    )
-
-
 def get_display_metadata(display_id: ID) -> DisplayMetaData:
     """Get display metadata by ID object
 

esphome/components/display/init_sequence.cpp

@@ -1,28 +0,0 @@
-#include "init_sequence.h"
-#include "esphome/core/hal.h"
-
-namespace esphome::display {
-
-InitSequenceStep InitSequenceReader::next(InitSequenceEntry &entry, uint8_t max_count) {
-  const size_t remaining = this->length_ - this->index_;
-  if (remaining == 0)
-    return INIT_SEQUENCE_STEP_END;
-  const uint8_t *pos = this->sequence_ + this->index_;
-  if (remaining >= 2) {
-    entry.value = progmem_read_byte(pos);
-    entry.count = progmem_read_byte(pos + 1);
-    entry.args = pos + 2;
-    if (entry.count == INIT_SEQUENCE_DELAY_FLAG) {
-      this->index_ += 2;
-      return INIT_SEQUENCE_STEP_DELAY;
-    }
-    if (entry.count <= max_count && remaining - 2 >= entry.count) {
-      this->index_ += 2 + entry.count;
-      return INIT_SEQUENCE_STEP_COMMAND;
-    }
-  }
-  this->index_ = this->length_;
-  return INIT_SEQUENCE_STEP_MALFORMED;
-}
-
-}  // namespace esphome::display

esphome/components/display/init_sequence.h

@@ -1,40 +0,0 @@
-#pragma once
-
-#include <cstddef>
-#include <cstdint>
-
-namespace esphome::display {
-
-/// Count byte that marks a delay entry: the byte before it is the delay in ms.
-static constexpr uint8_t INIT_SEQUENCE_DELAY_FLAG = 0xFF;
-
-/// Unscoped so `while (auto step = reader.next(entry))` stops at END.
-enum InitSequenceStep : uint8_t {
-  INIT_SEQUENCE_STEP_END = 0,
-  INIT_SEQUENCE_STEP_COMMAND,
-  INIT_SEQUENCE_STEP_DELAY,
-  INIT_SEQUENCE_STEP_MALFORMED,
-};
-
-/// `value` is the command or the delay in ms; `args` points into the (possibly PROGMEM) sequence.
-struct InitSequenceEntry {
-  const uint8_t *args;
-  uint8_t value;
-  uint8_t count;
-};
-
-/// Walks a mipi.flatten_sequence table (`cmd, count, args...` or `ms, 0xFF`) with progmem reads; resumable.
-class InitSequenceReader {
- public:
-  InitSequenceReader(const uint8_t *sequence, size_t length) : sequence_(sequence), length_(length) {}
-
-  /// Fill `entry` with the next entry; a command with more than `max_count` args is MALFORMED.
-  InitSequenceStep next(InitSequenceEntry &entry, uint8_t max_count = 0xFE);
-
- protected:
-  const uint8_t *sequence_;
-  size_t length_;
-  size_t index_{0};
-};
-
-}  // namespace esphome::display

esphome/components/ld2412/ld2412.cpp

@@ -186,23 +186,19 @@ static constexpr uint8_t CMD_DURATION_VALUE = 0x02;
 // Bitmasks for target states
 static constexpr uint8_t MOVE_BITMASK = 0x01;
 static constexpr uint8_t STILL_BITMASK = 0x02;
-// Header & Footer size
-static constexpr uint8_t HEADER_FOOTER_SIZE = 4;
-// Command Header & Footer
-static constexpr uint8_t CMD_FRAME_HEADER[HEADER_FOOTER_SIZE] = {0xFD, 0xFC, 0xFB, 0xFA};
-static constexpr uint8_t CMD_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0x04, 0x03, 0x02, 0x01};
+using ld24xx::CMD_FRAME_FOOTER;
+using ld24xx::CMD_FRAME_HEADER;
+using ld24xx::HEADER_FOOTER_SIZE;
+using ld24xx::validate_header_footer;
+// Smallest frames whose values can all be read: the last value, data footer and check, then the frame footer
+static constexpr uint8_t PERIODIC_FRAME_MIN = STILL_ENERGY + 3 + HEADER_FOOTER_SIZE;
+static constexpr uint8_t ENGINEERING_FRAME_MIN = LIGHT_SENSOR + 3 + HEADER_FOOTER_SIZE;
 // Data Header & Footer
 static constexpr uint8_t DATA_FRAME_HEADER[HEADER_FOOTER_SIZE] = {0xF4, 0xF3, 0xF2, 0xF1};
 static constexpr uint8_t DATA_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0xF8, 0xF7, 0xF6, 0xF5};
 // MAC address the module uses when Bluetooth is disabled
 static constexpr uint8_t NO_MAC[] = {0x08, 0x05, 0x04, 0x03, 0x02, 0x01};
 static constexpr uint8_t GATE_SENS_ACK_SIZE = ACK_PAYLOAD + TOTAL_GATES + HEADER_FOOTER_SIZE;
-// The length field counts the command word, the status word and the gates
-static constexpr uint16_t GATE_SENS_ACK_LENGTH = GATE_SENS_ACK_SIZE - COMMAND - HEADER_FOOTER_SIZE;
-
-static inline bool validate_header_footer(const uint8_t *header_footer, const uint8_t *buffer) {
-  return std::memcmp(header_footer, buffer, HEADER_FOOTER_SIZE) == 0;
-}
 
 void LD2412Component::dump_config() {
   char mac_s[MAC_ADDRESS_PRETTY_BUFFER_SIZE];
@@ -371,6 +367,9 @@ void LD2412Component::handle_periodic_data_() {
     0x02: Normal mode
   */
   bool engineering_mode = this->buffer_data_[DATA_TYPES] == 0x01;
+  if (this->buffer_pos_ < PERIODIC_FRAME_MIN) {
+    return;  // too short to hold the values
+  }
 #ifdef USE_SWITCH
   if (this->engineering_mode_switch_ != nullptr) {
     this->engineering_mode_switch_->publish_state(engineering_mode);
@@ -421,8 +420,7 @@ void LD2412Component::handle_periodic_data_() {
     this->detection_distance_sensor_.publish_state_if_not_dup(new_detect_distance);
   }
   if (engineering_mode) {
-    // Engineering mode needs at least LIGHT_SENSOR + 1 bytes
-    if (this->buffer_pos_ < LIGHT_SENSOR + 1) {
+    if (this->buffer_pos_ < ENGINEERING_FRAME_MIN) {
       ESP_LOGW(TAG, "Engineering mode packet too short: %u", this->buffer_pos_);
     } else {
       /*
@@ -477,24 +475,15 @@ static constexpr uint32_t GATE_QUERY_TIMEOUT_ID = 0;
 static constexpr uint32_t GATE_QUERY_TIMEOUT_MS = 2000;
 #endif
 
-bool LD2412Component::handle_ack_data_() {
+void LD2412Component::handle_ack_data_() {
   ESP_LOGV(TAG, "Handling ACK DATA for COMMAND %02X", this->buffer_data_[COMMAND]);
-  if (this->buffer_pos_ < 10) {
-    ESP_LOGW(TAG, "Invalid length");
-    return true;
-  }
-  if (!ld2412::validate_header_footer(CMD_FRAME_HEADER, this->buffer_data_)) {
-    char hex_buf[format_hex_pretty_size(HEADER_FOOTER_SIZE)];
-    ESP_LOGW(TAG, "Invalid header: %s", format_hex_pretty_to(hex_buf, this->buffer_data_, HEADER_FOOTER_SIZE));
-    return true;
-  }
   if (this->buffer_data_[COMMAND_STATUS] != 0x01) {
     ESP_LOGW(TAG, "Invalid status");
-    return true;
+    return;
   }
   if (this->buffer_data_[8] || this->buffer_data_[9]) {
     ESP_LOGW(TAG, "Invalid command: %02X, %02X", this->buffer_data_[8], this->buffer_data_[9]);
-    return true;
+    return;
   }
 
   switch (this->buffer_data_[COMMAND]) {
@@ -517,8 +506,8 @@ bool LD2412Component::handle_ack_data_() {
       break;
 
     case CMD_QUERY_VERSION: {
-      if (this->buffer_pos_ < 12 + sizeof(this->version_)) {
-        return false;
+      if (this->buffer_pos_ < 12 + sizeof(this->version_) + HEADER_FOOTER_SIZE) {
+        break;  // too short to hold a version
       }
       std::memcpy(this->version_, &this->buffer_data_[12], sizeof(this->version_));
       char version_s[20];
@@ -532,6 +521,9 @@ bool LD2412Component::handle_ack_data_() {
       break;
     }
     case CMD_QUERY_DISTANCE_RESOLUTION: {
+      if (this->buffer_pos_ < 11 + HEADER_FOOTER_SIZE) {
+        break;  // too short to hold the resolution
+      }
       const auto *distance_resolution = find_str(DISTANCE_RESOLUTIONS_BY_UINT, this->buffer_data_[10]);
       ESP_LOGV(TAG, "Distance resolution: %s", distance_resolution);
 #ifdef USE_SELECT
@@ -543,6 +535,9 @@ bool LD2412Component::handle_ack_data_() {
     }
 
     case CMD_QUERY_LIGHT_CONTROL: {
+      if (this->buffer_pos_ < 12 + HEADER_FOOTER_SIZE) {
+        break;  // too short to hold the light settings
+      }
       this->light_function_ = this->buffer_data_[10];
       this->light_threshold_ = this->buffer_data_[11];
       const auto *light_function_str = find_str(LIGHT_FUNCTIONS_BY_UINT, this->light_function_);
@@ -562,7 +557,7 @@ bool LD2412Component::handle_ack_data_() {
 
     case CMD_QUERY_MAC_ADDRESS: {
       if (this->buffer_pos_ < 20) {
-        return false;
+        break;  // too short to hold a MAC address
       }
 
       this->bluetooth_on_ = std::memcmp(&this->buffer_data_[10], NO_MAC, sizeof(NO_MAC)) != 0;
@@ -591,6 +586,9 @@ bool LD2412Component::handle_ack_data_() {
       break;
 
     case CMD_QUERY_DYNAMIC_BACKGROUND_CORRECTION: {
+      if (this->buffer_pos_ < 11 + HEADER_FOOTER_SIZE) {
+        break;  // too short to hold the state
+      }
       ESP_LOGV(TAG, "Handled query dynamic background correction");
       bool dynamic_background_correction_active = (this->buffer_data_[10] != 0x00);
 #ifdef USE_BINARY_SENSOR
@@ -613,14 +611,10 @@ bool LD2412Component::handle_ack_data_() {
     case CMD_QUERY_MOTION_GATE_SENS:
     case CMD_QUERY_STATIC_GATE_SENS: {
 #ifdef USE_NUMBER
-      const uint16_t declared = encode_uint16(this->buffer_data_[FRAME_LENGTH + 1], this->buffer_data_[FRAME_LENGTH]);
-      if (declared != GATE_SENS_ACK_LENGTH || this->buffer_pos_ > GATE_SENS_ACK_SIZE) {
-        // A truncated answer merged with the next frame, or a length this driver does not know
+      if (this->buffer_pos_ != GATE_SENS_ACK_SIZE) {
+        // A length this driver does not know
         ESP_LOGW(TAG, "Dropping gate threshold answer of %u bytes", this->buffer_pos_);
-        return true;
-      }
-      if (this->buffer_pos_ < GATE_SENS_ACK_SIZE) {
-        return false;  // the footer pattern appeared inside the payload, keep reading
+        return;
       }
       const bool motion = this->buffer_data_[COMMAND] == CMD_QUERY_MOTION_GATE_SENS;
       GateThresholds &group = this->gate_thresholds_(motion);
@@ -646,8 +640,8 @@ bool LD2412Component::handle_ack_data_() {
     case CMD_QUERY_BASIC_CONF:  // Query parameters response
     {
 #ifdef USE_NUMBER
-      if (this->buffer_pos_ < 15) {
-        return false;
+      if (this->buffer_pos_ < 15 + HEADER_FOOTER_SIZE) {
+        break;  // too short to hold the configuration
       }
       /*
         Moving distance range: 9th byte
@@ -677,42 +671,36 @@ bool LD2412Component::handle_ack_data_() {
     default:
       break;
   }
-
-  return true;
 }
 
 void LD2412Component::readline_(int readch) {
   if (readch < 0) {
     return;  // No data available
   }
-  if (this->buffer_pos_ < HEADER_FOOTER_SIZE && readch != DATA_FRAME_HEADER[this->buffer_pos_] &&
-      readch != CMD_FRAME_HEADER[this->buffer_pos_]) {
-    this->buffer_pos_ = 0;
-    return;
-  }
-  if (this->buffer_pos_ < MAX_LINE_LENGTH - 1) {
-    this->buffer_data_[this->buffer_pos_++] = readch;
-    this->buffer_data_[this->buffer_pos_] = 0;
-  } else {
-    // We should never get here, but just in case...
-    ESP_LOGW(TAG, "Max command length exceeded; ignoring");
-    this->buffer_pos_ = 0;
-  }
-  if (this->buffer_pos_ < 4) {
-    return;  // Not enough data to process yet
-  }
-  if (ld2412::validate_header_footer(DATA_FRAME_FOOTER, &this->buffer_data_[this->buffer_pos_ - 4])) {
+  // Periodic and command frames both carry their count after the header
+  ld24xx::feed_frame_byte(
+      this->buffer_data_, this->buffer_pos_, readch, DATA_FRAME_HEADER, ld24xx::cmd_frame_length,
+      [this](uint8_t frame_len) { return this->handle_frame_(frame_len); }, []() { ESP_LOGW(TAG, "Invalid length"); });
+}
+
+// Dispatches the frame of frame_len bytes at the start of the buffer when its footer is in place
+bool LD2412Component::handle_frame_(uint8_t frame_len) {
+  this->buffer_pos_ = frame_len;  // the handlers take the frame length from here
+  const uint8_t *tail = &this->buffer_data_[frame_len - HEADER_FOOTER_SIZE];
+  if (this->buffer_data_[0] == DATA_FRAME_HEADER[0]) {
+    if (!ld2412::validate_header_footer(DATA_FRAME_FOOTER, tail)) {
+      return false;
+    }
     ESP_LOGV_HEX(TAG, this->buffer_data_, this->buffer_pos_, MAX_LINE_LENGTH, "Handling Periodic Data: %s");
     this->handle_periodic_data_();
-    this->buffer_pos_ = 0;  // Reset position index for next message
-  } else if (ld2412::validate_header_footer(CMD_FRAME_FOOTER, &this->buffer_data_[this->buffer_pos_ - 4])) {
-    ESP_LOGV_HEX(TAG, this->buffer_data_, this->buffer_pos_, MAX_LINE_LENGTH, "Handling Ack Data: %s");
-    if (this->handle_ack_data_()) {
-      this->buffer_pos_ = 0;  // Reset position index for next message
-    } else {
-      ESP_LOGV(TAG, "Ack Data incomplete");
-    }
+    return true;
   }
+  if (!ld2412::validate_header_footer(CMD_FRAME_FOOTER, tail)) {
+    return false;
+  }
+  ESP_LOGV_HEX(TAG, this->buffer_data_, this->buffer_pos_, MAX_LINE_LENGTH, "Handling Ack Data: %s");
+  this->handle_ack_data_();
+  return true;
 }
 
 void LD2412Component::set_config_mode_(bool enable) {

esphome/components/ld2412/ld2412.h

@@ -111,7 +111,8 @@ class LD2412Component final : public Component, public uart::UARTDevice {
   void send_command_(uint8_t command_str, const uint8_t *command_value, uint8_t command_value_len);
   void set_config_mode_(bool enable);
   void handle_periodic_data_();
-  bool handle_ack_data_();
+  void handle_ack_data_();
+  bool handle_frame_(uint8_t frame_len);
   void readline_(int readch);
   void query_parameters_();
   void get_version_();

esphome/components/ld24xx/ld24xx.h

@@ -3,6 +3,8 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 
+#include <algorithm>
+#include <cstring>
 #include <memory>
 #include <span>
 
@@ -53,6 +55,74 @@ inline void format_version_str(const uint8_t *version, std::span<char, 20> buffe
            version[2]);
 }
 
+// Commands and their answers share this header, a little-endian byte count and this footer
+static constexpr uint8_t HEADER_FOOTER_SIZE = 4;
+static constexpr uint8_t CMD_FRAME_HEADER[HEADER_FOOTER_SIZE] = {0xFD, 0xFC, 0xFB, 0xFA};
+static constexpr uint8_t CMD_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0x04, 0x03, 0x02, 0x01};
+
+inline bool validate_header_footer(const uint8_t *header_footer, const uint8_t *buffer) {
+  return std::memcmp(header_footer, buffer, HEADER_FOOTER_SIZE) == 0;
+}
+
+// Whole command frame length, or 0 until the count arrives; 32 bit so 0xFFFF cannot wrap to 0
+inline uint32_t cmd_frame_length(const uint8_t *buffer, uint8_t count) {
+  if (count < HEADER_FOOTER_SIZE + 2) {
+    return 0;
+  }
+  return HEADER_FOOTER_SIZE + 2 + encode_value_le<uint16_t>(&buffer[HEADER_FOOTER_SIZE]) + HEADER_FOOTER_SIZE;
+}
+
+// Drops the first `from` bytes and anything after them that does not begin a header; returns the bytes kept
+inline uint8_t drop_to_next_header(uint8_t *buffer, uint8_t count, uint8_t from, const uint8_t *data_header) {
+  for (; from < count; from++) {
+    const size_t n = std::min<size_t>(HEADER_FOOTER_SIZE, count - from);
+    if (std::memcmp(&buffer[from], CMD_FRAME_HEADER, n) == 0 || std::memcmp(&buffer[from], data_header, n) == 0) {
+      std::memmove(buffer, &buffer[from], count - from);
+      return count - from;
+    }
+  }
+  return 0;
+}
+
+// Feeds one byte into a frame buffer. A frame opens with the command header or `data_header` and ends at
+// `frame_length(buffer, count)` bytes (0 while unknown); `handle_frame(len)` returns false for a footer out
+// of place. A dropped or oversized frame calls `on_drop()`. The handler may overwrite `pos`; the splitter
+// works from the count it saved.
+template<size_t N, typename LengthFn, typename HandleFn, typename DropFn>
+void feed_frame_byte(uint8_t (&buffer)[N], uint8_t &pos, uint8_t byte, const uint8_t *data_header,
+                     LengthFn frame_length, HandleFn handle_frame, DropFn on_drop) {
+  // The first byte picks the header; bytes that do not continue it are dropped
+  if (pos > 0 && pos < HEADER_FOOTER_SIZE) {
+    const uint8_t *header = buffer[0] == data_header[0] ? data_header : CMD_FRAME_HEADER;
+    if (byte != header[pos]) {
+      pos = 0;
+    }
+  }
+  if (pos == 0 && byte != data_header[0] && byte != CMD_FRAME_HEADER[0]) {
+    return;
+  }
+  buffer[pos++] = byte;
+  // Drain every whole frame left in the buffer
+  while (true) {
+    const uint32_t frame_len = frame_length(buffer, pos);
+    if (frame_len == 0 || (frame_len <= N && pos < frame_len)) {
+      return;
+    }
+    const uint8_t total = pos;
+    // Keep only what begins a header: after the frame, or after its first byte when it is dropped
+    uint8_t from = 1;
+    if (frame_len <= N && handle_frame(static_cast<uint8_t>(frame_len))) {
+      from = frame_len;
+    } else {
+      on_drop();
+    }
+    pos = drop_to_next_header(buffer, total, from, data_header);
+    if (pos == 0) {
+      return;
+    }
+  }
+}
+
 #ifdef USE_SENSOR
 template<typename T> using SensorWithDedup = sensor::SensorWithDedup<T>;
 #endif

tests/components/display/test_init_sequence.cpp

@@ -1,82 +0,0 @@
-#include <gtest/gtest.h>
-
-#include <cstdint>
-
-#include "esphome/components/display/init_sequence.h"
-
-namespace esphome::display::testing {
-
-TEST(InitSequenceReader, WalksCommandsAndDelays) {
-  static const uint8_t SEQ[] = {0x11, 0x00, 120, 0xFF, 0x3A, 0x01, 0x55, 0x2A, 0x02, 0x00, 0xEF};
-  InitSequenceReader reader(SEQ, sizeof(SEQ));
-  InitSequenceEntry entry{};
-
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(entry.value, 0x11);
-  EXPECT_EQ(entry.count, 0);
-
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_DELAY);
-  EXPECT_EQ(entry.value, 120);
-
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(entry.value, 0x3A);
-  ASSERT_EQ(entry.count, 1);
-  EXPECT_EQ(entry.args, &SEQ[6]);
-
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(entry.value, 0x2A);
-  ASSERT_EQ(entry.count, 2);
-  EXPECT_EQ(entry.args[0], 0x00);
-  EXPECT_EQ(entry.args[1], 0xEF);
-
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-}
-
-TEST(InitSequenceReader, EmptySequenceEnds) {
-  InitSequenceReader reader(nullptr, 0);
-  InitSequenceEntry entry{};
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-}
-
-// A count above 127 is a real length, not a flag bit.
-TEST(InitSequenceReader, HonoursFullCount) {
-  uint8_t seq[2 + 253 + 2] = {0x32, 253};
-  seq[2 + 253] = 0x29;
-  InitSequenceReader reader(seq, sizeof(seq));
-  InitSequenceEntry entry{};
-
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(entry.value, 0x32);
-  EXPECT_EQ(entry.count, 253);
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(entry.value, 0x29);
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-}
-
-TEST(InitSequenceReader, TruncatedHeaderIsMalformed) {
-  static const uint8_t SEQ[] = {0x11, 0x00, 0x29};
-  InitSequenceReader reader(SEQ, sizeof(SEQ));
-  InitSequenceEntry entry{};
-  ASSERT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_COMMAND);
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_MALFORMED);
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-}
-
-TEST(InitSequenceReader, ShortArgsAreMalformed) {
-  static const uint8_t SEQ[] = {0x2A, 0x04, 0x00, 0x00, 0x00};
-  InitSequenceReader reader(SEQ, sizeof(SEQ));
-  InitSequenceEntry entry{};
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_MALFORMED);
-  EXPECT_EQ(reader.next(entry), INIT_SEQUENCE_STEP_END);
-}
-
-TEST(InitSequenceReader, CountOverMaxIsMalformed) {
-  static const uint8_t SEQ[] = {10, 0xFF, 0x2A, 0x02, 0x00, 0xEF};
-  InitSequenceReader reader(SEQ, sizeof(SEQ));
-  InitSequenceEntry entry{};
-  ASSERT_EQ(reader.next(entry, 1), INIT_SEQUENCE_STEP_DELAY);
-  EXPECT_EQ(reader.next(entry, 1), INIT_SEQUENCE_STEP_MALFORMED);
-}
-
-}  // namespace esphome::display::testing

tests/components/ld24xx/ld24xx_frame_splitter.cpp

@@ -0,0 +1,152 @@
+#include <cstdint>
+#include <cstring>
+#include <vector>
+#include <gtest/gtest.h>
+#include "esphome/components/ld24xx/ld24xx.h"
+
+namespace esphome::ld24xx::testing {
+
+namespace {
+constexpr uint8_t DATA_FRAME_HEADER[HEADER_FOOTER_SIZE] = {0xF4, 0xF3, 0xF2, 0xF1};
+constexpr uint8_t DATA_FRAME_FOOTER[HEADER_FOOTER_SIZE] = {0xF8, 0xF7, 0xF6, 0xF5};
+constexpr uint8_t DATA_FRAME_SIZE = 12;  // header, four payload bytes, footer
+constexpr size_t BUFFER_SIZE = 40;
+
+// Command frame around the payload
+std::vector<uint8_t> make_cmd_frame(const std::vector<uint8_t> &payload) {
+  std::vector<uint8_t> frame(std::begin(CMD_FRAME_HEADER), std::end(CMD_FRAME_HEADER));
+  frame.push_back(payload.size());
+  frame.push_back(0x00);
+  frame.insert(frame.end(), payload.begin(), payload.end());
+  frame.insert(frame.end(), std::begin(CMD_FRAME_FOOTER), std::end(CMD_FRAME_FOOTER));
+  return frame;
+}
+
+std::vector<uint8_t> make_data_frame(uint8_t fill) {
+  std::vector<uint8_t> frame(std::begin(DATA_FRAME_HEADER), std::end(DATA_FRAME_HEADER));
+  frame.insert(frame.end(), DATA_FRAME_SIZE - 2 * HEADER_FOOTER_SIZE, fill);
+  frame.insert(frame.end(), std::begin(DATA_FRAME_FOOTER), std::end(DATA_FRAME_FOOTER));
+  return frame;
+}
+}  // namespace
+
+// Data frames are fixed size, command frames carry their count, as in the radar components
+class LD24xxFrameSplitterTest : public ::testing::Test {
+ protected:
+  void feed_(const std::vector<uint8_t> &bytes) {
+    for (uint8_t byte : bytes) {
+      feed_frame_byte(
+          this->buffer_, this->pos_, byte, DATA_FRAME_HEADER,
+          [](const uint8_t *buffer, uint8_t count) -> uint32_t {
+            if (count < HEADER_FOOTER_SIZE) {
+              return 0;
+            }
+            return buffer[0] == DATA_FRAME_HEADER[0] ? DATA_FRAME_SIZE : cmd_frame_length(buffer, count);
+          },
+          [this](uint8_t frame_len) { return this->handle_frame_(frame_len); }, [this]() { this->drops_++; });
+    }
+  }
+
+  bool handle_frame_(uint8_t frame_len) {
+    const uint8_t *footer = this->buffer_[0] == DATA_FRAME_HEADER[0] ? DATA_FRAME_FOOTER : CMD_FRAME_FOOTER;
+    if (!validate_header_footer(footer, &this->buffer_[frame_len - HEADER_FOOTER_SIZE])) {
+      return false;
+    }
+    this->frames_.emplace_back(this->buffer_, this->buffer_ + frame_len);
+    return true;
+  }
+
+  uint8_t buffer_[BUFFER_SIZE];
+  uint8_t pos_{0};
+  std::vector<std::vector<uint8_t>> frames_;
+  int drops_{0};
+};
+
+TEST_F(LD24xxFrameSplitterTest, FooterBytesInThePayloadDoNotEndTheFrame) {
+  auto frame = make_cmd_frame({0x61, 0x01, 0x00, 0x00, 0x04, 0x03, 0x02, 0x01, 0x55});
+  this->feed_(frame);
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], frame);
+  EXPECT_EQ(this->pos_, 0);
+  EXPECT_EQ(this->drops_, 0);
+}
+
+TEST_F(LD24xxFrameSplitterTest, BytesBeforeAHeaderAreNeverBuffered) {
+  this->feed_({0x00, 0x11, 0xFC, 0xFB, 0xFA, 0x04});
+  EXPECT_EQ(this->pos_, 0);
+  this->feed_(make_data_frame(0x22));
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], make_data_frame(0x22));
+}
+
+TEST_F(LD24xxFrameSplitterTest, AHeaderRestartsWhenItsBytesStopMatching) {
+  // F3 cannot continue the command header, and FD after FC starts it over
+  this->feed_({0xFD, 0xF3, 0xFD, 0xFC, 0xFD, 0xFC, 0xFB, 0xFA, 0x00, 0x00});
+  EXPECT_EQ(this->pos_, 6) << "only the header that matched through and its count are buffered";
+  this->feed_({0x04, 0x03, 0x02, 0x01});
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], make_cmd_frame({}));
+  EXPECT_EQ(this->drops_, 0);
+}
+
+TEST_F(LD24xxFrameSplitterTest, ImpossibleCountsAreDroppedAndTheNextFrameParsed) {
+  // 0xFFF6 totals 65536, which must not wrap to 0
+  this->feed_({0xFD, 0xFC, 0xFB, 0xFA, 0xF6, 0xFF});
+  this->feed_({0xFD, 0xFC, 0xFB, 0xFA, 0xFF, 0xFF});
+  EXPECT_EQ(this->drops_, 2);
+  EXPECT_EQ(this->pos_, 0);
+  this->feed_(make_data_frame(0x33));
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], make_data_frame(0x33));
+}
+
+TEST_F(LD24xxFrameSplitterTest, AFrameCaughtInsideADroppedFrameIsReplayed) {
+  // The count reaches 20 bytes in, past the whole frame that follows
+  std::vector<uint8_t> bytes = {0xFD, 0xFC, 0xFB, 0xFA, 0x0A, 0x00, 0x61, 0x01};
+  auto inner = make_data_frame(0x44);
+  bytes.insert(bytes.end(), inner.begin(), inner.end());
+  this->feed_(bytes);
+  EXPECT_EQ(this->drops_, 1);
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], inner);
+  EXPECT_EQ(this->pos_, 0);
+}
+
+TEST_F(LD24xxFrameSplitterTest, EveryWholeFrameLeftByADropIsDrained) {
+  // The window holds two whole data frames and the start of a third
+  std::vector<uint8_t> bytes = {0xFD, 0xFC, 0xFB, 0xFA, 0x18, 0x00, 0x61, 0x01};
+  for (uint8_t fill : {0x55, 0x66}) {
+    auto inner = make_data_frame(fill);
+    bytes.insert(bytes.end(), inner.begin(), inner.end());
+  }
+  bytes.insert(bytes.end(), {0xF4, 0xF3});
+  this->feed_(bytes);
+  EXPECT_EQ(this->drops_, 1);
+  ASSERT_EQ(this->frames_.size(), 2u);
+  EXPECT_EQ(this->frames_[0], make_data_frame(0x55));
+  EXPECT_EQ(this->frames_[1], make_data_frame(0x66));
+  EXPECT_EQ(this->pos_, 2) << "the partial header at the end stays buffered";
+}
+
+TEST_F(LD24xxFrameSplitterTest, AWrongFooterDropsOnlyThatFrame) {
+  auto bad = make_cmd_frame({0x01, 0x02});
+  bad[bad.size() - 1] = 0xEE;
+  this->feed_(bad);
+  EXPECT_EQ(this->drops_, 1);
+  EXPECT_TRUE(this->frames_.empty());
+  this->feed_(make_cmd_frame({0x03}));
+  ASSERT_EQ(this->frames_.size(), 1u);
+  EXPECT_EQ(this->frames_[0], make_cmd_frame({0x03}));
+}
+
+TEST_F(LD24xxFrameSplitterTest, BackToBackFramesOfBothKinds) {
+  this->feed_(make_data_frame(0x01));
+  this->feed_(make_cmd_frame({0xA0, 0x01, 0x00, 0x00}));
+  this->feed_(make_data_frame(0x02));
+  ASSERT_EQ(this->frames_.size(), 3u);
+  EXPECT_EQ(this->frames_[1], make_cmd_frame({0xA0, 0x01, 0x00, 0x00}));
+  EXPECT_EQ(this->frames_[2], make_data_frame(0x02));
+  EXPECT_EQ(this->drops_, 0);
+}
+
+}  // namespace esphome::ld24xx::testing

tests/integration/README.md

@@ -58,8 +58,30 @@ The `InitialStateHelper` class solves a common problem in integration tests: whe
 - Provides debug logging to track state reception (use `--log-cli-level=DEBUG`)
 - Safe for concurrent use with multiple entity types
 
-**Future work:**
-Consider converting existing integration tests to use `InitialStateHelper` for more reliable state tracking and to eliminate race conditions related to initial state broadcasts.
+#### Subscribing after the initial states (`state_utils.py`)
+
+`subscribe_after_initial_states()` does the `InitialStateHelper` setup in one call: it subscribes, waits
+for every entity's connect time state, and fails the test with the entities still missing on timeout.
+It returns a `StateSubscription` with `initial_states` (by key) and a `waiter`, a `StateWaiter` that sees
+every later state. `waiter.next_state(key=..., state_type=...)` arms a wait for the next matching state;
+call it before sending the command. `press_and_wait()` presses a button and returns the next state of a
+type, from one entity when `key=` is given:
+
+```python
+from .state_utils import press_and_wait, subscribe_after_initial_states
+
+entities, _ = await client.list_entities_services()
+sub = await subscribe_after_initial_states(client, entities)
+
+state = await press_and_wait(client, entities, sub.waiter, "set_position", CoverState)
+assert state.position == pytest.approx(0.5, abs=0.01)
+
+next_light = sub.waiter.next_state(key=light.key, state_type=LightState)
+client.light_command(key=light.key, state=True)
+assert (await next_light).state is True
+```
+
+Pass `on_state=` as well when the test also needs to collect every state.
 
 #### Entity Lookup Helpers (`state_utils.py`)
 
@@ -203,46 +225,24 @@ async def test_my_sensor(
 
 ##### State Subscription Pattern
 
-**Recommended: Using InitialStateHelper**
+**Recommended: Using subscribe_after_initial_states**
 
-When an API client connects, ESPHome automatically sends the current state of all entities. The `InitialStateHelper` (from `state_utils.py`) handles this by swallowing these initial states and only forwarding subsequent state changes to your test callback:
+When an API client connects, ESPHome automatically sends the current state of all entities.
+`subscribe_after_initial_states()` (from `state_utils.py`) swallows these initial states and only forwards
+subsequent state changes, to your callback and to the returned `waiter`:
 
 ```python
-from .state_utils import InitialStateHelper
+from .state_utils import subscribe_after_initial_states
 
-# Track state changes with futures
-loop = asyncio.get_running_loop()
-states: dict[int, EntityState] = {}
-state_future: asyncio.Future[EntityState] = loop.create_future()
-
-
-def on_state(state: EntityState) -> None:
-    """This callback only receives NEW state changes, not initial states."""
-    states[state.key] = state
-    # Check for specific condition using isinstance
-    if isinstance(state, SensorState) and state.state == expected_value:
-        if not state_future.done():
-            state_future.set_result(state)
-
-
-# Get entities and set up state synchronization
 entities, services = await client.list_entities_services()
-initial_state_helper = InitialStateHelper(entities)
+sub = await subscribe_after_initial_states(client, entities)
 
-# Subscribe with the wrapper that filters initial states
-client.subscribe_states(initial_state_helper.on_state_wrapper(on_state))
-
-# Wait for all initial states to be broadcast; on timeout this fails the test
-# and lists the entities that never sent one
-await initial_state_helper.wait_for_initial_states()
-
-# Now perform your test actions - on_state will only receive new changes
-# ... trigger state changes ...
-
-# Wait for expected state; on timeout the test fails and shows the states received
-result = await wait_or_fail(
-    state_future, 5.0, "Expected state not received", states=states
+# Arm the wait before the action that produces the state
+expected = sub.waiter.expect(
+    lambda s: isinstance(s, SensorState) and s.state == expected_value
 )
+# ... trigger state changes ...
+result = await expected
 ```
 
 **Legacy: Manual State Tracking**
@@ -386,38 +386,34 @@ async with run_compiled(yaml_config, line_callback=on_log_line):
     # Test implementation
 ```
 
-Example using futures for specific log patterns:
+To wait for log lines, use `LineWaiter` (`log_utils.py`) instead of a hand written
+callback with one future per pattern:
 ```python
 import re
 
-loop = asyncio.get_running_loop()
-connected_future = loop.create_future()
-service_future = loop.create_future()
+from .log_utils import LineWaiter
 
-# Patterns to match
-connected_pattern = re.compile(r"Client .* connected from")
-service_pattern = re.compile(r"Service called")
+log = LineWaiter()
+# Arm expectations before the action that logs them; any number may be pending.
+connected = log.expect(re.compile(r"Client .* connected from"))
+value = log.expect(re.compile(r"value=(\d+)"))
 
-
-def check_output(line: str) -> None:
-    """Check log output for expected messages."""
-    if not connected_future.done() and connected_pattern.search(line):
-        connected_future.set_result(True)
-    elif not service_future.done() and service_pattern.search(line):
-        service_future.set_result(True)
-
-
-async with run_compiled(yaml_config, line_callback=check_output):
+async with run_compiled(yaml_config, line_callback=log.callback):
     async with api_client_connected() as client:
-        # Wait for specific log message
-        await asyncio.wait_for(connected_future, timeout=5.0)
-
-        # Do test actions...
-
-        # Wait for service log
-        await asyncio.wait_for(service_future, timeout=5.0)
+        await log.wait(connected)
+        match = await log.wait(value, timeout=5.0, msg="no value logged")
+        assert match.group(1) == "42"
+        assert log.count("Service called") == 1
 ```
 
+- `expect(pattern)` only matches lines that arrive after the call. A `str` matches as a
+  substring and resolves to the line; a compiled regex is searched and resolves to its match.
+  Each expectation resolves on the next matching line, so two armed for the same text both
+  resolve on its first occurrence: arm the second after the first resolves, or use `count`.
+- `wait(future)` fails the test on timeout with the pattern and the last 20 log lines.
+- `wait_for(*needles)` also matches lines seen before the call, but only one may be pending.
+- `count(pattern)` counts the lines seen so far.
+
 **Note**: Tests that monitor log messages typically have fewer race conditions compared to state-based testing, making them more reliable. However, be aware that the host platform currently does not have a thread-safe logger, so logging from threads will not work correctly.
 
 ##### Timeout Handling

tests/integration/fixtures/uart_mock_ld2412.yaml

@@ -30,7 +30,7 @@ uart_mock:
     # Target state: 0x03 (moving + still)
     # detection_distance = 100 (LD2412 computes from moving target when MOVE_BITMASK set)
     #
-    # Frame layout (24 bytes):
+    # Frame layout (23 bytes):
     #   [0-3]   F4 F3 F2 F1 = data frame header
     #   [4-5]   0D 00       = length 13
     #   [6]     02          = data type (normal)
@@ -41,10 +41,9 @@ uart_mock:
     #   [12-13] 78 00       = still distance 120 (0x0078)
     #   [14]    19          = still energy 25
     #   [15-16] 64 00       = detect distance bytes (ignored by LD2412 code)
-    #   [17]    00          = padding
-    #   [18]    55          = data footer marker
-    #   [19]    00          = CRC/check
-    #   [20-23] F8 F7 F6 F5 = data frame footer
+    #   [17]    55          = data footer marker
+    #   [18]    00          = CRC/check
+    #   [19-22] F8 F7 F6 F5 = data frame footer
     - delay: 100ms
       inject_rx:
         [
@@ -57,7 +56,6 @@ uart_mock:
           0x78, 0x00,
           0x19,
           0x64, 0x00,
-          0x00,
           0x55, 0x00,
           0xF8, 0xF7, 0xF6, 0xF5,
         ]
@@ -69,17 +67,13 @@ uart_mock:
       inject_rx: [0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11, 0x22]
 
     # Phase 3 (t=400ms): Truncated frame (header + partial data, no footer)
-    # Starts with valid data frame header so parser accepts it.
-    # After this, buffer_pos_ = 8.
+    # Starts with a valid data frame header, so the parser waits for the 23 bytes its length announces.
     - delay: 100ms
       inject_rx: [0xF4, 0xF3, 0xF2, 0xF1, 0x0D, 0x00, 0x02, 0xAA]
 
-    # Phase 4 (t=600ms): Overflow - inject 60 bytes of 0xFF (MAX_LINE_LENGTH=54)
-    # Buffer has 8 bytes from phase 3 (garbage in phase 2 was rejected).
-    # Overflow math: buffer_pos_ starts at 8, overflow triggers when
-    # buffer_pos_ reaches 53 (MAX_LINE_LENGTH - 1). Need 45 more bytes to
-    # fill positions 8-52, then byte 46 triggers overflow. After overflow,
-    # buffer_pos_ = 0 and remaining 0xFF bytes are rejected (don't match header).
+    # Phase 4 (t=600ms): 60 bytes of 0xFF
+    # The first 15 complete the truncated frame's 23 bytes without its footer, so it is dropped
+    # with an 'Invalid length' warning; the rest cannot start a header and are dropped too.
     - delay: 200ms
       inject_rx:
         [
@@ -91,8 +85,8 @@ uart_mock:
           0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
         ]
 
-    # Phase 5 (t=700ms): Valid frame after overflow - recovery test
-    # Buffer was reset by overflow. This valid frame should parse correctly.
+    # Phase 5 (t=700ms): Valid frame after the garbage - recovery test
+    # The buffer is empty again, so this valid frame should parse correctly.
     # Moving target: 50cm, energy 100
     # Still target: 75cm, energy 80
     # detection_distance = 50 (moving target distance, since MOVE_BITMASK set)
@@ -108,7 +102,72 @@ uart_mock:
           0x4B, 0x00,
           0x50,
           0x32, 0x00,
-          0x00,
+          0x55, 0x00,
+          0xF8, 0xF7, 0xF6, 0xF5,
+        ]
+
+    # Phase 6 (t=3200ms): Values that spell the command footer 04 03 02 01
+    # Moving distance 772 (0x0304), moving energy 2, still distance 1: bytes 9 to 12 are the
+    # command frame footer, which must not end the frame early.
+    # Still energy 5, detection_distance = 772 (moving target distance, since MOVE_BITMASK set).
+    # The sensors hold and throttle values for a second, so the gap lets the phase 5 states
+    # reach the test before these replace them.
+    - delay: 2500ms
+      inject_rx:
+        [
+          0xF4, 0xF3, 0xF2, 0xF1,
+          0x0D, 0x00,
+          0x02, 0xAA,
+          0x03,
+          0x04, 0x03,
+          0x02,
+          0x01, 0x00,
+          0x05,
+          0x04, 0x03,
+          0x55, 0x00,
+          0xF8, 0xF7, 0xF6, 0xF5,
+        ]
+
+    # Phase 7 (t=5700ms): Truncated frame merged with a complete one
+    # The eight header bytes announce a 23 byte frame, so its window takes in the first 15 bytes of
+    # the valid frame that follows. The merged frame has no footer where the count says, so it is
+    # dropped and the bytes after its header are replayed, which recovers the valid frame.
+    # Moving distance 400, moving energy 7, still distance 200, still energy 9, detection_distance = 400
+    - delay: 2500ms
+      inject_rx:
+        [
+          0xF4, 0xF3, 0xF2, 0xF1, 0x0D, 0x00, 0x02, 0xAA,
+          0xF4, 0xF3, 0xF2, 0xF1,
+          0x0D, 0x00,
+          0x02, 0xAA,
+          0x03,
+          0x90, 0x01,
+          0x07,
+          0xC8, 0x00,
+          0x09,
+          0x90, 0x01,
+          0x55, 0x00,
+          0xF8, 0xF7, 0xF6, 0xF5,
+        ]
+
+    # Phase 8 (t=8200ms): Impossible counts, then a complete frame
+    # A command header counting 0xFFF6 bytes (65536 in total, which must not wrap to 0) and one counting
+    # 0xFFFF are each dropped as soon as the count arrives, and the valid frame after them is parsed.
+    # Moving distance 600, moving energy 11, still distance 300, still energy 13, detection distance 600
+    - delay: 2500ms
+      inject_rx:
+        [
+          0xFD, 0xFC, 0xFB, 0xFA, 0xF6, 0xFF,
+          0xFD, 0xFC, 0xFB, 0xFA, 0xFF, 0xFF,
+          0xF4, 0xF3, 0xF2, 0xF1,
+          0x0D, 0x00,
+          0x02, 0xAA,
+          0x03,
+          0x58, 0x02,
+          0x0B,
+          0x2C, 0x01,
+          0x0D,
+          0x58, 0x02,
           0x55, 0x00,
           0xF8, 0xF7, 0xF6, 0xF5,
         ]

tests/integration/fixtures/uart_mock_ld2412_short_answers.yaml

@@ -0,0 +1,88 @@
+esphome:
+  name: uart-mock-ld2412-short-answers
+
+host:
+api:
+  batch_delay: 0ms  # Disable batching to receive all state updates
+logger:
+  level: VERBOSE
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+
+# Dummy uart entry to satisfy ld2412's DEPENDENCIES = ["uart"]
+# The actual UART bus used is the uart_mock component below
+uart:
+  baud_rate: 115200
+  port: /dev/null
+
+# Answers cut short, so the footer sits where their values would be, each followed by a whole one
+uart_mock:
+  id: mock_uart
+  baud_rate: 256000
+  auto_start: false
+  injections:
+    # Version answer cut after two version bytes
+    - delay: 100ms
+      inject_rx:
+        [
+          0xFD, 0xFC, 0xFB, 0xFA, 0x08, 0x00, 0xA0, 0x01, 0x00, 0x00,
+          0x00, 0x01, 0x07, 0x02,
+          0x04, 0x03, 0x02, 0x01,
+        ]
+
+    # Basic configuration answer cut after the minimum gate 7
+    - delay: 100ms
+      inject_rx:
+        [
+          0xFD, 0xFC, 0xFB, 0xFA, 0x05, 0x00, 0x12, 0x01, 0x00, 0x00,
+          0x07,
+          0x04, 0x03, 0x02, 0x01,
+        ]
+
+    # Whole version answer: firmware type 1, version 2.07.22062416
+    - delay: 100ms
+      inject_rx:
+        [
+          0xFD, 0xFC, 0xFB, 0xFA, 0x0C, 0x00, 0xA0, 0x01, 0x00, 0x00,
+          0x00, 0x01, 0x07, 0x02, 0x16, 0x24, 0x06, 0x22,
+          0x04, 0x03, 0x02, 0x01,
+        ]
+
+    # Whole basic configuration answer: gates 3 to 9, timeout 10 s, output pin level low
+    - delay: 100ms
+      inject_rx:
+        [
+          0xFD, 0xFC, 0xFB, 0xFA, 0x09, 0x00, 0x12, 0x01, 0x00, 0x00,
+          0x03, 0x09, 0x0A, 0x00, 0x01,
+          0x04, 0x03, 0x02, 0x01,
+        ]
+
+ld2412:
+  id: ld2412_dev
+  uart_id: mock_uart
+
+number:
+  - platform: ld2412
+    ld2412_id: ld2412_dev
+    min_distance_gate:
+      name: "Min Distance Gate"
+    max_distance_gate:
+      name: "Max Distance Gate"
+    timeout:
+      name: "Timeout"
+
+text_sensor:
+  - platform: ld2412
+    ld2412_id: ld2412_dev
+    version:
+      name: "Version"
+
+button:
+  - platform: template
+    name: "Start Scenario"
+    id: start_scenario_btn
+    on_press:
+      - lambda: 'id(mock_uart).start_scenario();'

tests/integration/fixtures/uart_mock_ld2412_truncated_answer.yaml

@@ -37,7 +37,7 @@ uart_mock:
           0x04, 0x00,  # length 4
           0xFE, 0x01,  # answer to command 0x00FE
           0x00, 0x00,  # status: success
-          0x04, 0x03, 0x02, 0x01,  # its footer; the merged 40-byte frame gets dropped
+          0x04, 0x03, 0x02, 0x01,  # its footer; the 28 bytes the answer announced hold no footer, so it is dropped
         ]
   # A complete answer after setup proves the parser recovered
   injections:

tests/integration/log_utils.py

@@ -3,23 +3,47 @@
 from __future__ import annotations
 
 import asyncio
+import re
+from typing import Any, overload
+
+from .wait_utils import wait_or_fail
+
+type LinePattern = str | re.Pattern[str]
+type LineMatch = str | re.Match[str]
+
+
+def _match(pattern: LinePattern, line: str) -> LineMatch | None:
+    """Return ``line`` if a str pattern is in it, or the search match of a regex."""
+    if isinstance(pattern, str):
+        return line if pattern in line else None
+    return pattern.search(line)
 
 
 class LineWaiter:
-    """Collects log lines and lets a test await one containing all needles.
+    """Collects log lines and lets a test await lines that match.
 
     Pass ``callback`` as ``run_compiled``'s ``line_callback``; the callback runs
-    on the test's own event loop, so futures are resolved directly. Only one
-    ``wait_for`` may be outstanding at a time (tests await sequentially).
+    on the test's own event loop, so futures are resolved directly. ``wait_for``
+    also matches lines seen before the call, and only one may be outstanding at a
+    time. ``expect`` matches only later lines, and any number may be armed at once;
+    each resolves on the next matching line, so two armed for the same text both
+    resolve on its first occurrence. Arm the second after the first, or use ``count``.
     """
 
     def __init__(self) -> None:
         self.lines: list[str] = []
         self._needles: tuple[str, ...] = ()
         self._future: asyncio.Future | None = None
+        self._expectations: dict[asyncio.Future[Any], LinePattern] = {}
 
     def callback(self, line: str) -> None:
         self.lines.append(line)
+        for future, pattern in list(self._expectations.items()):
+            if future.done():
+                del self._expectations[future]
+            elif (match := _match(pattern, line)) is not None:
+                future.set_result(match)
+                del self._expectations[future]
         if (
             self._future is not None
             and not self._future.done()
@@ -46,3 +70,38 @@ class LineWaiter:
         finally:
             self._future = None
             self._needles = ()
+
+    @overload
+    def expect(self, pattern: str) -> asyncio.Future[str]: ...  # noqa: E704
+
+    @overload
+    def expect(self, pattern: re.Pattern[str]) -> asyncio.Future[re.Match[str]]: ...  # noqa: E704
+
+    def expect(self, pattern: LinePattern) -> asyncio.Future[LineMatch]:
+        """Arm a wait for the next line matching ``pattern``; earlier lines never match.
+
+        A str matches as a substring and resolves to the line; a compiled regex is
+        searched and resolves to its match. Arm it before the action that logs the line.
+        """
+        future: asyncio.Future[LineMatch] = asyncio.get_running_loop().create_future()
+        self._expectations[future] = pattern
+        return future
+
+    async def wait[T: str | re.Match[str]](
+        self,
+        future: asyncio.Future[T],
+        timeout: float = 5.0,
+        msg: str = "log line not seen",
+    ) -> T:
+        """Await a future from ``expect``; on timeout fail with its pattern and the last lines."""
+        return await wait_or_fail(
+            future,
+            timeout,
+            msg,
+            pattern=self._expectations.get(future),
+            lines=self.lines,
+        )
+
+    def count(self, pattern: LinePattern) -> int:
+        """Return how many lines seen so far match ``pattern``."""
+        return sum(_match(pattern, line) is not None for line in self.lines)

tests/integration/state_utils.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Awaitable, Callable
+from dataclasses import dataclass
 import logging
 from typing import TypeVar
 
@@ -100,6 +101,22 @@ class StateWaiter:
         self._waiters.append(entry)
         return self._wait(entry, timeout, label)
 
+    def next_state[T: EntityState](
+        self,
+        key: int | None = None,
+        state_type: type[T] = EntityState,
+        timeout: float = 5.0,
+    ) -> Awaitable[T]:
+        """Arm a wait for the next ``state_type`` state, for entity ``key`` if given.
+
+        Like :meth:`expect`, call it before sending the command and await the result afterwards.
+        """
+        return self.expect(
+            lambda s: isinstance(s, state_type) and (key is None or s.key == key),
+            timeout,
+            state_type.__name__ if key is None else f"{state_type.__name__} key={key}",
+        )
+
     async def _wait(
         self,
         entry: tuple[Callable[[EntityState], bool], asyncio.Future[EntityState]],
@@ -402,6 +419,58 @@ class InitialStateHelper:
         )
 
 
+@dataclass(frozen=True, slots=True)
+class StateSubscription:
+    """A state subscription that is past the connect time states."""
+
+    initial_states: dict[int, EntityState]
+    waiter: StateWaiter
+
+
+async def subscribe_after_initial_states(
+    client: APIClient,
+    entities: list[EntityInfo],
+    on_state: Callable[[EntityState], None] | None = None,
+    timeout: float = 5.0,
+) -> StateSubscription:
+    """Subscribe to states and wait until every entity has sent its connect time state.
+
+    Later states go to ``on_state`` (if given) and to the returned ``waiter``. The connect time
+    states are kept in ``initial_states`` by key. Fails the test listing the entities still missing.
+    """
+    helper = InitialStateHelper(entities)
+    waiter = StateWaiter()
+
+    def forward(state: EntityState) -> None:
+        waiter.on_state(state)
+        if on_state is not None:
+            on_state(state)
+
+    client.subscribe_states(helper.on_state_wrapper(forward))
+    await helper.wait_for_initial_states(timeout)
+    return StateSubscription(helper.initial_states, waiter)
+
+
+async def press_and_wait[T: EntityState](
+    client: APIClient,
+    entities: list[EntityInfo],
+    waiter: StateWaiter,
+    button: str,
+    state_type: type[T],
+    *,
+    key: int | None = None,
+    timeout: float = 5.0,
+) -> T:
+    """Press the button whose object_id contains ``button`` and return the next ``state_type`` state.
+
+    Pass the entity's ``key`` when the fixture has more than one entity of that type.
+    """
+    btn = require_entity(entities, button, ButtonInfo)
+    next_state = waiter.next_state(key=key, state_type=state_type, timeout=timeout)
+    client.button_command(btn.key)
+    return await next_state
+
+
 class SensorStateCollector:
     """Collects sensor, binary sensor, and text sensor state updates with wait helpers.
 

tests/integration/test_uart_mock_ld2412.py

@@ -5,9 +5,12 @@ test_uart_mock_ld2412 (normal mode):
   1. Happy path - valid data frame publishes correct sensor values
   2. Garbage resilience - random bytes don't crash the component
   3. Truncated frame handling - partial frame doesn't corrupt state
-  4. Buffer overflow recovery - overflow resets the parser
-  5. Post-overflow parsing - next valid frame after overflow is parsed correctly
-  6. TX logging - verifies LD2412 sends expected setup commands
+  4. Truncated frame recovery - the frame is dropped once its length is reached
+  5. Post-garbage parsing - the next valid frame is parsed correctly
+  6. Footer bytes in the values - a frame whose values spell the command footer is parsed whole
+  7. Replay after a drop - a valid frame caught inside a dropped frame's window is still parsed
+  8. Impossible counts - a length field of 0xFFF6 or 0xFFFF is dropped and the next frame is parsed
+  9. TX logging - verifies LD2412 sends expected setup commands
 
 test_uart_mock_ld2412_engineering (engineering mode):
   1. Engineering mode frames with per-gate energy data and light sensor
@@ -24,6 +27,7 @@ test_uart_mock_ld2412_engineering_truncated (truncated engineering mode):
 The gate threshold tests (footer_in_payload, truncated_answer, requery_after_giveup) cover
 answers that hold the frame footer or are truncated, writes that fill the gates without a
 number from the module's values, and writes held back until the module reports them.
+test_uart_mock_ld2412_short_answers: answers cut short publish nothing, the whole ones after them do.
 """
 
 from __future__ import annotations
@@ -39,6 +43,7 @@ from aioesphomeapi import (
     EntityState,
     NumberInfo,
     NumberState,
+    TextSensorState,
 )
 import pytest
 
@@ -139,7 +144,7 @@ async def test_uart_mock_ld2412(
     run_compiled: RunCompiledFunction,
     api_client_connected: APIClientConnectedFactory,
 ) -> None:
-    """Test LD2412 data parsing with happy path, garbage, overflow, and recovery."""
+    """Test LD2412 data parsing with happy path, garbage, a truncated frame, and recovery."""
     waiter = LineWaiter()
 
     collector = SensorStateCollector(
@@ -165,6 +170,22 @@ async def test_uart_mock_ld2412(
             and pytest.approx(100.0) in collector.sensor_states["moving_energy"]
             and pytest.approx(80.0) in collector.sensor_states["still_energy"]
             and pytest.approx(50.0) in collector.sensor_states["detection_distance"]
+            and pytest.approx(772.0) in collector.sensor_states["moving_distance"]
+            and pytest.approx(400.0) in collector.sensor_states["moving_distance"]
+            # Every value asserted below, so no state can still be in flight when the waiter fires
+            and pytest.approx(2.0) in collector.sensor_states["moving_energy"]
+            and pytest.approx(1.0) in collector.sensor_states["still_distance"]
+            and pytest.approx(5.0) in collector.sensor_states["still_energy"]
+            and pytest.approx(772.0) in collector.sensor_states["detection_distance"]
+            and pytest.approx(7.0) in collector.sensor_states["moving_energy"]
+            and pytest.approx(200.0) in collector.sensor_states["still_distance"]
+            and pytest.approx(9.0) in collector.sensor_states["still_energy"]
+            and pytest.approx(400.0) in collector.sensor_states["detection_distance"]
+            and pytest.approx(600.0) in collector.sensor_states["moving_distance"]
+            and pytest.approx(11.0) in collector.sensor_states["moving_energy"]
+            and pytest.approx(300.0) in collector.sensor_states["still_distance"]
+            and pytest.approx(13.0) in collector.sensor_states["still_energy"]
+            and pytest.approx(600.0) in collector.sensor_states["detection_distance"]
         )
     )
 
@@ -192,17 +213,17 @@ async def test_uart_mock_ld2412(
         assert collector.sensor_states["detection_distance"][0] == pytest.approx(100.0)
 
         # Wait for the recovery frame (Phase 5) to be parsed
-        # This proves the component survived garbage + truncated + overflow
+        # This proves the component survived garbage + truncated frame + filler bytes
         await wait_or_fail(
             recovery_received,
-            3.0,
+            15.0,
             "Timeout waiting for recovery frame",
             sensor_states=collector.sensor_states,
         )
 
-        # Verify overflow warning was logged
-        assert any("Max command length exceeded" in line for line in waiter.lines), (
-            "Expected 'Max command length exceeded' warning in logs"
+        # Verify the truncated frame was dropped with a warning
+        assert any("Invalid length" in line for line in waiter.lines), (
+            "Expected 'Invalid length' warning in logs"
         )
 
         # Verify LD2412 sent setup commands (TX logging)
@@ -224,6 +245,27 @@ async def test_uart_mock_ld2412(
         assert pytest.approx(80.0) in collector.sensor_states["still_energy"]
         assert pytest.approx(50.0) in collector.sensor_states["detection_distance"]
 
+        # Phase 6: the values 04 03 02 01 did not end the frame early
+        assert pytest.approx(772.0) in collector.sensor_states["moving_distance"]
+        assert pytest.approx(2.0) in collector.sensor_states["moving_energy"]
+        assert pytest.approx(1.0) in collector.sensor_states["still_distance"]
+        assert pytest.approx(5.0) in collector.sensor_states["still_energy"]
+        assert pytest.approx(772.0) in collector.sensor_states["detection_distance"]
+
+        # Phase 7: the valid frame inside the dropped frame's window was replayed and parsed
+        assert pytest.approx(400.0) in collector.sensor_states["moving_distance"]
+        assert pytest.approx(7.0) in collector.sensor_states["moving_energy"]
+        assert pytest.approx(200.0) in collector.sensor_states["still_distance"]
+        assert pytest.approx(9.0) in collector.sensor_states["still_energy"]
+        assert pytest.approx(400.0) in collector.sensor_states["detection_distance"]
+
+        # Phase 8: both impossible counts were dropped and the frame after them was parsed
+        assert pytest.approx(600.0) in collector.sensor_states["moving_distance"]
+        assert pytest.approx(11.0) in collector.sensor_states["moving_energy"]
+        assert pytest.approx(300.0) in collector.sensor_states["still_distance"]
+        assert pytest.approx(13.0) in collector.sensor_states["still_energy"]
+        assert pytest.approx(600.0) in collector.sensor_states["detection_distance"]
+
         # Verify binary sensors detected targets (from Phase 1 frame)
         assert collector.binary_states["has_target"][0] is True
         assert collector.binary_states["has_moving_target"][0] is True
@@ -531,7 +573,7 @@ async def test_uart_mock_ld2412_truncated_answer(
 
         try:
             _, gate_0_state, gate_5_state = await asyncio.gather(
-                waiter.wait_for("Dropping gate threshold answer", timeout=5.0),
+                waiter.wait_for("Invalid length", timeout=5.0),
                 gate_0_read,
                 gate_5_read,
             )
@@ -653,3 +695,56 @@ async def test_uart_mock_ld2412_requery_after_giveup(
         assert gate_0_state.state == pytest.approx(25.0)
         assert gate_5_values
         assert all(value == pytest.approx(30.0) for value in gate_5_values)
+
+
+@pytest.mark.asyncio
+async def test_uart_mock_ld2412_short_answers(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that answers cut short publish nothing and the whole answers after them do."""
+    loop = asyncio.get_running_loop()
+    # Number object_id: the value from the whole basic configuration answer
+    expected = {"min_distance_gate": 3.0, "max_distance_gate": 8.0, "timeout": 10.0}
+    number_states: dict[str, list[float]] = {name: [] for name in expected}
+    version_states: list[str] = []
+    key_to_name: dict[int, str] = {}
+    all_received = loop.create_future()
+
+    def on_state(state: EntityState) -> None:
+        if isinstance(state, TextSensorState) and not state.missing_state:
+            version_states.append(state.state)
+        elif (
+            isinstance(state, NumberState)
+            and not state.missing_state
+            and (name := key_to_name.get(state.key)) is not None
+        ):
+            number_states[name].append(state.state)
+        if not all_received.done() and version_states and all(number_states.values()):
+            all_received.set_result(True)
+
+    async with (
+        run_compiled(yaml_config),
+        api_client_connected() as client,
+    ):
+        entities, _ = await client.list_entities_services()
+        key_to_name.update(
+            {require_entity(entities, name, NumberInfo).key: name for name in expected}
+        )
+        await _wait_initial(client, entities, on_state)
+
+        start_btn = require_entity(entities, "start_scenario", ButtonInfo)
+        client.button_command(start_btn.key)
+
+        await wait_or_fail(
+            all_received,
+            5.0,
+            "Timeout waiting for the whole answers",
+            number_states=number_states,
+            version_states=version_states,
+        )
+        # Each entity saw exactly one value, the one from the whole answer
+        assert version_states == ["2.07.22062416"]
+        for name, value in expected.items():
+            assert number_states[name] == pytest.approx([value]), name

tests/unit_tests/components/test_display.py

@@ -1,4 +1,4 @@
-"""Tests for display.add_writer and display.config_has_writer."""
+"""Tests for display.add_writer."""
 
 from unittest.mock import AsyncMock, MagicMock, patch
 
@@ -6,8 +6,7 @@ import pytest
 
 from esphome import codegen as cg
 from esphome.components import display
-from esphome.components.display import CONF_SHOW_TEST_CARD
-from esphome.const import CONF_AUTO_CLEAR_ENABLED, CONF_LAMBDA, CONF_PAGES
+from esphome.const import CONF_LAMBDA
 
 
 @pytest.mark.parametrize(
@@ -40,20 +39,3 @@ async def test_add_writer_without_lambda_does_nothing() -> None:
 
     process.assert_not_awaited()
     add.assert_not_called()
-
-
-@pytest.mark.parametrize(
-    ("config", "expected"),
-    [
-        ({}, False),
-        ({CONF_AUTO_CLEAR_ENABLED: True}, True),
-        ({CONF_AUTO_CLEAR_ENABLED: False}, False),
-        ({CONF_AUTO_CLEAR_ENABLED: "unspecified"}, False),
-        ({CONF_PAGES: []}, True),
-        ({CONF_LAMBDA: "x"}, True),
-        ({CONF_SHOW_TEST_CARD: True}, True),
-        ({CONF_SHOW_TEST_CARD: False}, False),
-    ],
-)
-def test_config_has_writer(config: dict, expected: bool) -> None:
-    assert display.config_has_writer(config) is expected

tests/unit_tests/test_integration_log_utils.py

@@ -0,0 +1,81 @@
+"""Tests for the integration test LineWaiter."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from tests.integration.log_utils import LineWaiter
+
+
+@pytest.mark.asyncio
+async def test_expect_matches_only_later_lines() -> None:
+    waiter = LineWaiter()
+    waiter.callback("[I][app]: ready")
+    ready = waiter.expect("ready")
+    value = waiter.expect(re.compile(r"value=(\d+)"))
+    assert not ready.done()
+
+    waiter.callback("[D][x]: value=42")
+    waiter.callback("[I][app]: ready again")
+    assert await waiter.wait(ready) == "[I][app]: ready again"
+    match = await waiter.wait(value)
+    assert isinstance(match, re.Match)
+    assert match.group(1) == "42"
+    # wait_for still matches lines seen before the call.
+    assert await waiter.wait_for("app", "ready") == "[I][app]: ready"
+
+
+@pytest.mark.asyncio
+async def test_wait_timeout_reports_pattern_and_lines() -> None:
+    waiter = LineWaiter()
+    for i in range(30):
+        waiter.callback(f"line {i}")
+    future = waiter.expect("never")
+    with pytest.raises(pytest.fail.Exception) as err:
+        await waiter.wait(future, 0.01, "boot message missing")
+    message = str(err.value)
+    assert message.startswith("boot message missing (after 0.01s)")
+    assert "pattern: 'never'" in message
+    assert "lines (last 20 of 30):" in message
+    assert message.endswith("line 29")
+    assert future.cancelled()
+    # The cancelled expectation is dropped on the next line.
+    waiter.callback("never")
+    assert not waiter._expectations
+
+
+def test_count() -> None:
+    waiter = LineWaiter()
+    for line in ("tick 1", "tock", "tick 2"):
+        waiter.callback(line)
+    assert waiter.count("tick") == 2
+    assert waiter.count(re.compile(r"t\w+k$")) == 1
+    assert waiter.count("missing") == 0
+
+
+@pytest.mark.asyncio
+async def test_expect_resolves_from_callback_while_waiting() -> None:
+    waiter = LineWaiter()
+    first = waiter.expect("first")
+    second = waiter.expect("second")
+    loop = asyncio.get_running_loop()
+    loop.call_soon(waiter.callback, "second")
+    loop.call_soon(waiter.callback, "first")
+    assert await waiter.wait(first) == "first"
+    assert await waiter.wait(second) == "second"
+
+
+@pytest.mark.asyncio
+async def test_line_waiter_expectations_share_a_matching_line() -> None:
+    waiter = LineWaiter()
+    first = waiter.expect("tick")
+    second = waiter.expect("tick")
+    waiter.callback("tick 1")
+    assert first.result() == second.result() == "tick 1"
+    third = waiter.expect("tick")
+    waiter.callback("tick 2")
+    assert third.result() == "tick 2"
+    assert waiter.count("tick") == 2

tests/unit_tests/test_integration_state_subscribe.py

@@ -0,0 +1,108 @@
+"""Tests for the state subscription helpers in tests/integration/state_utils.py."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import Callable
+
+from aioesphomeapi import ButtonInfo, EntityState, SensorInfo, SensorState, SwitchState
+import pytest
+
+from tests.integration.state_utils import (
+    StateSubscription,
+    StateWaiter,
+    press_and_wait,
+    subscribe_after_initial_states,
+)
+
+ENTITIES = [
+    SensorInfo(object_id="temp", key=1),
+    SensorInfo(object_id="humidity", key=2),
+    ButtonInfo(object_id="set_temp", key=3),
+]
+
+
+class FakeClient:
+    """Records the state callback and button presses."""
+
+    def __init__(self) -> None:
+        self.callback: Callable[[EntityState], None] | None = None
+        self.pressed: list[int] = []
+
+    def subscribe_states(self, callback: Callable[[EntityState], None]) -> None:
+        self.callback = callback
+
+    def button_command(self, key: int) -> None:
+        self.pressed.append(key)
+        self.callback(SensorState(key=1, state=42.0))
+
+
+async def _subscribe(client: FakeClient, **kwargs: object) -> StateSubscription:
+    task = asyncio.create_task(
+        subscribe_after_initial_states(client, ENTITIES, **kwargs)
+    )
+    await asyncio.sleep(0)
+    client.callback(SensorState(key=1, state=1.0))
+    client.callback(SensorState(key=2, state=2.0))
+    return await task
+
+
+@pytest.mark.asyncio
+async def test_subscribe_swallows_initial_states_and_forwards_later_ones() -> None:
+    client = FakeClient()
+    received: list[EntityState] = []
+    sub = await _subscribe(client, on_state=received.append)
+    assert sub.initial_states[1].state == 1.0
+    assert sub.initial_states[2].state == 2.0
+    assert received == []
+
+    next_state = sub.waiter.next_state(key=2, state_type=SensorState)
+    client.callback(SensorState(key=1, state=3.0))
+    client.callback(SensorState(key=2, state=4.0))
+    assert (await next_state).state == 4.0
+    assert [s.state for s in received] == [3.0, 4.0]
+
+
+@pytest.mark.asyncio
+async def test_subscribe_timeout_lists_missing_entities() -> None:
+    client = FakeClient()
+    task = asyncio.create_task(
+        subscribe_after_initial_states(client, ENTITIES, timeout=0.01)
+    )
+    await asyncio.sleep(0)
+    client.callback(SensorState(key=1, state=1.0))
+    with pytest.raises(pytest.fail.Exception, match=r"still_waiting[\s\S]*humidity"):
+        await task
+
+
+@pytest.mark.asyncio
+async def test_next_state_filters_by_type_and_times_out() -> None:
+    waiter = StateWaiter()
+    next_switch = waiter.next_state(state_type=SwitchState)
+    waiter.on_state(SensorState(key=1, state=1.0))
+    waiter.on_state(SwitchState(key=5, state=True))
+    assert (await next_switch).key == 5
+    with pytest.raises(TimeoutError, match="SwitchState key=9"):
+        await waiter.next_state(key=9, state_type=SwitchState, timeout=0.01)
+
+
+@pytest.mark.asyncio
+async def test_press_and_wait_presses_button_and_returns_state() -> None:
+    client = FakeClient()
+    sub = await _subscribe(client)
+    state = await press_and_wait(client, ENTITIES, sub.waiter, "set_temp", SensorState)
+    assert client.pressed == [3]
+    assert state.state == 42.0
+
+
+@pytest.mark.asyncio
+async def test_press_and_wait_waits_for_the_given_key() -> None:
+    client = FakeClient()
+    sub = await _subscribe(client)
+    pending = asyncio.ensure_future(
+        press_and_wait(client, ENTITIES, sub.waiter, "set_temp", SensorState, key=2)
+    )
+    await asyncio.sleep(0)
+    assert not pending.done()  # the press published key 1
+    client.callback(SensorState(key=2, state=55.0))
+    assert (await pending).state == 55.0