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

# Conflicts:
#	tests/component_tests/logger/test_logger.py

esphome/components/logger/__init__.py

@@ -37,6 +37,7 @@ from esphome.types import ConfigType
 _LOGGER = logging.getLogger(__name__)
 
 CODEOWNERS = ["@esphome/core"]
+DOMAIN = "logger"
 logger_ns = cg.esphome_ns.namespace("logger")
 LOG_LEVELS = {
     "NONE": cg.global_ns.ESPHOME_LOG_LEVEL_NONE,
@@ -108,8 +109,6 @@ HARDWARE_UART_TO_SERIAL = {
         UART0: cg.global_ns.Serial,
         UART0_SWAP: cg.global_ns.Serial,
         UART1: cg.global_ns.Serial1,
-        UART2: cg.global_ns.Serial2,
-        DEFAULT: cg.global_ns.Serial,
     },
     PLATFORM_RP2: {
         UART0: cg.global_ns.Serial1,
@@ -503,13 +502,10 @@ async def to_code(config: ConfigType) -> None:
     CORE.data.setdefault(DOMAIN, {})[CONF_LEVEL] = level
     tx_buffer_size = config[CONF_TX_BUFFER_SIZE]
     cg.add_define("ESPHOME_LOGGER_TX_BUFFER_SIZE", tx_buffer_size)
-    # Determine task log buffer size. The buffer is a direct member of Logger
-    # (no separate heap allocation).
-    task_log_buffer_size = 0
-    if CORE.is_esp32 or CORE.is_libretiny or CORE.is_nrf52:
-        task_log_buffer_size = config[CONF_TASK_LOG_BUFFER_SIZE]
-    elif CORE.is_host:
-        task_log_buffer_size = 64  # Fixed 64 slots for host
+    # The host has a fixed 64 slots
+    task_log_buffer_size = (
+        64 if CORE.is_host else config.get(CONF_TASK_LOG_BUFFER_SIZE, 0)
+    )
     if task_log_buffer_size > 0:
         cg.add_define("USE_ESPHOME_TASK_LOG_BUFFER")
         cg.add_define("ESPHOME_TASK_LOG_BUFFER_SIZE", task_log_buffer_size)
@@ -647,7 +643,6 @@ async def _late_logger_init(config: ConfigType) -> None:
 
         if config[CONF_HARDWARE_UART] == USB_CDC:
             add_idf_sdkconfig_option("CONFIG_ESP_CONSOLE_USB_CDC", True)
-            cg.add_define("USE_LOGGER_UART_SELECTION_USB_CDC")
         elif config[CONF_HARDWARE_UART] == USB_SERIAL_JTAG:
             add_idf_sdkconfig_option("CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG", True)
             cg.add_define("USE_LOGGER_UART_SELECTION_USB_SERIAL_JTAG")
@@ -667,7 +662,10 @@ async def _late_logger_init(config: ConfigType) -> None:
             cg.add_define("USE_ESP32_LOG_V2")
             # --wrap: a strong definition collides; see logger_esp32.cpp
             cg.add_build_flag("-Wl,--wrap=esp_log_format")
-    if CORE.is_rp2 and config[CONF_HARDWARE_UART] == USB_CDC:
+    # Zephyr polls the USB port only when it logs there
+    if config.get(CONF_HARDWARE_UART) == USB_CDC and (
+        has_serial_logging or not CORE.is_nrf52
+    ):
         cg.add_define("USE_LOGGER_UART_SELECTION_USB_CDC")
     # Define platform support flags for components that need auto-detection
     try:
@@ -718,7 +716,6 @@ async def _late_logger_init(config: ConfigType) -> None:
             if config[CONF_HARDWARE_UART] == UART1:
                 zephyr_add_overlay("""&uart1 { status = "okay";};""")
             if config[CONF_HARDWARE_UART] == USB_CDC:
-                cg.add_define("USE_LOGGER_UART_SELECTION_USB_CDC")
                 zephyr_add_prj_conf("UART_LINE_CTRL", True)
 
     # Register at end for safe mode
@@ -739,8 +736,6 @@ async def _late_logger_init(config: ConfigType) -> None:
             conf,
         )
 
-    CORE.add_job(final_step)
-
 
 def validate_printf(value: ConfigType) -> ConfigType:
     # https://stackoverflow.com/questions/30011379/how-can-i-parse-a-c-format-string-in-python
@@ -875,11 +870,6 @@ FILTER_SOURCE_FILES = filter_source_files_from_platform(
     }
 )
 
-# Keys for CORE.data storage
-DOMAIN = "logger"
-KEY_LEVEL_LISTENERS = "level_listeners"
-KEY_LOG_LISTENERS = "log_listeners"
-
 
 def request_logger_level_listeners() -> None:
     """Request that logger level listeners be compiled in.
@@ -888,29 +878,13 @@ def request_logger_level_listeners() -> None:
     function during their code generation. This enables the add_level_listener()
     method and compiles in the listener vector.
     """
-    CORE.data.setdefault(DOMAIN, {})[KEY_LEVEL_LISTENERS] = True
+    cg.add_define("USE_LOGGER_LEVEL_LISTENERS")
+
+
+_request_log_listener_slot = cg.slot_counter("ESPHOME_LOG_MAX_LISTENERS")
 
 
 def request_log_listener() -> None:
-    """Request a log listener slot.
-
-    Components that need to receive log messages should call this function
-    during their code generation. This increments the listener count used
-    to size the StaticVector.
-    """
-    data = CORE.data.setdefault(DOMAIN, {})
-    data[KEY_LOG_LISTENERS] = data.get(KEY_LOG_LISTENERS, 0) + 1
-
-
-@coroutine_with_priority(CoroPriority.FINAL)
-async def final_step() -> None:
-    """Final code generation step to configure optional logger features."""
-    domain_data = CORE.data.get(DOMAIN, {})
-    if domain_data.get(KEY_LEVEL_LISTENERS, False):
-        cg.add_define("USE_LOGGER_LEVEL_LISTENERS")
-
-    # Only generate log listener code if any component needs it
-    log_listener_count = domain_data.get(KEY_LOG_LISTENERS, 0)
-    if log_listener_count > 0:
-        cg.add_define("USE_LOG_LISTENERS")
-        cg.add_define("ESPHOME_LOG_MAX_LISTENERS", log_listener_count)
+    """Reserve a log listener slot; call once per listener from to_code."""
+    cg.add_define("USE_LOG_LISTENERS")
+    _request_log_listener_slot()

esphome/components/logger/logger.cpp

@@ -32,7 +32,7 @@ void HOT Logger::log_vprintf_(uint8_t level, const char *tag, int line, const ch
   // Get task handle once - used for both main task check and passing to non-main thread handler
   TaskHandle_t current_task = xTaskGetCurrentTaskHandle();
   const bool is_main_task = (current_task == this->main_task_);
-#elif (USE_ZEPHYR)
+#elif defined(USE_ZEPHYR)
   k_tid_t current_task = k_current_get();
   const bool is_main_task = (current_task == this->main_task_);
 #else  // USE_HOST
@@ -57,10 +57,10 @@ void HOT Logger::log_vprintf_(uint8_t level, const char *tag, int line, const ch
   // (we already have the handle from the main task check above).
   // Host: pass a stack buffer for pthread_getname_np to write into.
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)
-  const char *thread_name = get_thread_name_(current_task);
+  const char *thread_name = this->get_thread_name_(current_task);
 #elif defined(USE_ZEPHYR)
   char thread_name_buf[MAX_POINTER_REPRESENTATION];
-  const char *thread_name = get_thread_name_(thread_name_buf, current_task);
+  const char *thread_name = this->get_thread_name_(thread_name_buf, current_task);
 #else  // USE_HOST
   char thread_name_buf[THREAD_NAME_BUF_SIZE];
   const char *thread_name = this->get_thread_name_(thread_name_buf);
@@ -103,10 +103,10 @@ void Logger::log_vprintf_non_main_thread_(uint8_t level, const char *tag, int li
   {
 #ifdef USE_HOST
     // Host always has console output - no baud_rate check needed
-    static const size_t MAX_CONSOLE_LOG_MSG_SIZE = 512;
+    static constexpr size_t MAX_CONSOLE_LOG_MSG_SIZE = 512;
 #else
     // Maximum size for console log messages (includes null terminator)
-    static const size_t MAX_CONSOLE_LOG_MSG_SIZE = 144;
+    static constexpr size_t MAX_CONSOLE_LOG_MSG_SIZE = 144;
 #endif
     char console_buffer[MAX_CONSOLE_LOG_MSG_SIZE];  // MUST be stack allocated for thread safety
     LogBuffer buf{console_buffer, MAX_CONSOLE_LOG_MSG_SIZE};
@@ -118,13 +118,11 @@ void Logger::log_vprintf_non_main_thread_(uint8_t level, const char *tag, int li
 }
 #else
 // Implementation for single-task platforms (ESP8266, RP2040)
-// Logging calls are NOT thread-safe: global_recursion_guard_ is a plain bool and tx_buffer_ has no locking.
-// Not a problem in practice yet since Zephyr has no API support (logs are console-only).
+// Logging calls are NOT thread-safe: the recursion guard is a plain bool and tx_buffer_ has no locking.
 void HOT Logger::log_vprintf_(uint8_t level, const char *tag, int line, const char *format, va_list args) {  // NOLINT
-  if (level > this->level_for(tag) || global_recursion_guard_)
+  if (level > this->level_for(tag) || this->main_task_recursion_guard_)
     return;
-  // Other single-task platforms don't have thread names, so pass nullptr
-  this->log_message_to_buffer_and_send_(global_recursion_guard_, level, tag, line, format, args, nullptr);
+  this->log_message_to_buffer_and_send_(this->main_task_recursion_guard_, level, tag, line, format, args, nullptr);
 }
 #endif  // USE_ESP32 || USE_HOST || USE_LIBRETINY || USE_ZEPHYR
 
@@ -136,10 +134,10 @@ void HOT Logger::log_vprintf_(uint8_t level, const char *tag, int line, const ch
 //
 void Logger::log_vprintf_(uint8_t level, const char *tag, int line, const __FlashStringHelper *format,
                           va_list args) {  // NOLINT
-  if (level > this->level_for(tag) || global_recursion_guard_)
+  if (level > this->level_for(tag) || this->main_task_recursion_guard_)
     return;
 
-  this->log_message_to_buffer_and_send_(global_recursion_guard_, level, tag, line, format, args, nullptr);
+  this->log_message_to_buffer_and_send_(this->main_task_recursion_guard_, level, tag, line, format, args, nullptr);
 }
 #endif  // USE_ESP8266
 
@@ -213,11 +211,11 @@ void Logger::process_messages_() {
       this->write_log_buffer_to_console_(buf);
     }
   }
+  // Zephyr with USB CDC keeps the loop running for cdc_loop_()
 #if !(defined(USE_ZEPHYR) && defined(USE_LOGGER_UART_SELECTION_USB_CDC))
   else {
-    // No messages to process, disable loop if appropriate
-    // This reduces overhead when there's no async logging activity
-    this->disable_loop_when_buffer_empty_();
+    // A concurrent enable_loop_soon_any_context() still wakes the next iteration
+    this->disable_loop();
   }
 #endif
 #endif  // USE_ESPHOME_TASK_LOG_BUFFER
@@ -265,7 +263,7 @@ void Logger::boot_log_capture_(uint8_t level, const char *tag, const LogBuffer &
 
 void Logger::replay_boot_logs() {
   // The replay shares tx_buffer_ with normal logging, so it is dropped like any other re-entrant log
-  bool &recursion_guard = this->main_loop_recursion_guard_();
+  bool &recursion_guard = this->main_task_recursion_guard_;
   if (recursion_guard)
     return;
   this->boot_log_done_ = true;  // Stops capture first, so the replay output is not buffered again
@@ -342,7 +340,7 @@ void Logger::dump_config() {
   }
 #endif
 #ifdef USE_ZEPHYR
-  dump_crash_();
+  this->dump_crash_();
 #ifdef USE_BOOTLOADER_ADAFRUIT
   this->dump_bootloader_();
 #endif

esphome/components/logger/logger.h

@@ -42,9 +42,6 @@ struct device;
 namespace esphome::logger {
 
 /** Lightweight callback for receiving log messages without virtual dispatch overhead.
- *
- * Replaces the former LogListener virtual interface to eliminate per-implementer
- * vtable sub-tables and thunk code (~39 bytes saved per class that used LogListener).
  *
  * Usage:
  *   // In your component's setup():
@@ -73,7 +70,7 @@ struct LogCallback {
  *    public:
  *     void setup() override {
  *       if (logger::global_logger != nullptr)
- *         logger::global_logger->add_logger_level_listener(this);
+ *         logger::global_logger->add_level_listener(this);
  *     }
  *     void on_log_level_change(uint8_t level) override {
  *       // Handle log level change
@@ -138,7 +135,7 @@ enum UARTSelection : uint8_t {
  * - On ESP32: Uses task-specific recursion guards
  *   * Main task: Uses a dedicated boolean member variable for efficiency
  *   * Other tasks: Uses pthread TLS with a dynamically allocated key for task-specific state
- * - On other platforms: Uses a simple global recursion guard
+ * - On single-task platforms: Uses the main task guard alone
  *
  * We use pthread TLS via pthread_key_create to create a unique key for storing
  * task-specific recursion state, which:
@@ -157,19 +154,25 @@ class Logger final : public Component {
 #endif
   /// Manually set the baud rate for serial, set to 0 to disable.
   void set_baud_rate(uint32_t baud_rate) { this->baud_rate_ = baud_rate; }
-  uint32_t get_baud_rate() const { return baud_rate_; }
+  uint32_t get_baud_rate() const { return this->baud_rate_; }
 #if defined(USE_ARDUINO) && !defined(USE_ESP32)
-  Stream *get_hw_serial() const { return hw_serial_; }
+  Stream *get_hw_serial() const { return this->hw_serial_; }
 #endif
 #ifdef USE_ESP32
-  uart_port_t get_uart_num() const { return uart_num_; }
-  void create_pthread_key() { pthread_key_create(&log_recursion_key_, nullptr); }
+  /// UART_NUM_0 when logging to USB
+  uart_port_t get_uart_num() const {
+#if defined(USE_LOGGER_UART_SELECTION_USB_CDC) || defined(USE_LOGGER_UART_SELECTION_USB_SERIAL_JTAG)
+    return UART_NUM_0;
+#else
+    return static_cast<uart_port_t>(this->uart_);
 #endif
-#ifdef USE_HOST
-  void create_pthread_key() { pthread_key_create(&log_recursion_key_, nullptr); }
+  }
+#endif
+#if defined(USE_ESP32) || defined(USE_HOST)
+  void create_pthread_key() { pthread_key_create(&this->log_recursion_key_, nullptr); }
 #endif
 #if defined(USE_ESP32) || defined(USE_ESP8266) || defined(USE_RP2) || defined(USE_LIBRETINY) || defined(USE_ZEPHYR)
-  void set_uart_selection(UARTSelection uart_selection) { uart_ = uart_selection; }
+  void set_uart_selection(UARTSelection uart_selection) { this->uart_ = uart_selection; }
   /// Get the UART used by the logger.
   UARTSelection get_uart() const { return this->uart_; }
 #endif
@@ -246,10 +249,13 @@ class Logger final : public Component {
   void cdc_loop_();
 #endif
   void process_messages_();
-#if defined(USE_HOST) || defined(USE_ZEPHYR)
-  void write_msg_(const char *msg, uint16_t len);
+  // msg already ends in a newline
+#if defined(USE_ARDUINO) && !defined(USE_ESP32)
+  inline void HOT write_msg_(const char *msg, uint16_t len) { this->hw_serial_->write(msg, len); }
+#elif defined(USE_ESP32)
+  inline void write_msg_(const char *msg, uint16_t len);  // Defined in logger_esp32.h
 #else
-  inline void write_msg_(const char *msg, uint16_t len);  // Defined in platform-specific logger_*.h
+  void write_msg_(const char *msg, uint16_t len);
 #endif
 
   // Format a log message with printf-style arguments and write it to a buffer with header, footer, and null terminator
@@ -317,7 +323,6 @@ class Logger final : public Component {
 
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
   // Helper to format a pre-formatted message from the task log buffer and notify listeners
-  // Used by process_messages_ to avoid code duplication between ESP32 and host platforms
   inline void HOT format_buffered_message_and_notify_(uint8_t level, const char *tag, uint16_t line,
                                                       const char *thread_name, const char *text, uint16_t text_length,
                                                       LogBuffer &buf) {
@@ -359,15 +364,8 @@ class Logger final : public Component {
 #ifdef USE_HOST
   pthread_t main_thread_{};  // Main thread for pthread_equal() comparison
 #endif
-#ifdef USE_ESP32
-  // Task-specific recursion guards:
-  // - Main task uses a dedicated member variable for efficiency
-  // - Other tasks use pthread TLS with a dynamically created key via pthread_key_create
-  pthread_key_t log_recursion_key_;  // 4 bytes
-  uart_port_t uart_num_;             // 4 bytes (enum defaults to int size)
-#endif
-#ifdef USE_HOST
-  // Thread-specific recursion guards using pthread TLS
+#if defined(USE_ESP32) || defined(USE_HOST)
+  // Non-main task recursion guard (pthread TLS)
   pthread_key_t log_recursion_key_;
 #endif
 
@@ -392,23 +390,14 @@ class Logger final : public Component {
   bool boot_log_done_{false};     // Set on first replay; stops further capture
 #endif
   uint8_t current_level_{ESPHOME_LOG_LEVEL_VERY_VERBOSE};
-#if defined(USE_ESP32) || defined(USE_ESP8266) || defined(USE_RP2) || defined(USE_ZEPHYR)
-  UARTSelection uart_{UART_SELECTION_UART0};  // Must match cpp_default_uart in __init__.py
+#if defined(USE_ESP32) || defined(USE_ESP8266) || defined(USE_RP2) || defined(USE_LIBRETINY) || defined(USE_ZEPHYR)
+  // 0 is UART0, or DEFAULT on LibreTiny; must match cpp_default_uart in __init__.py
+  UARTSelection uart_{};
 #endif
-#ifdef USE_LIBRETINY
-  UARTSelection uart_{UART_SELECTION_DEFAULT};  // Must match cpp_default_uart in __init__.py
-#endif
-#if defined(USE_ESP32) || defined(USE_HOST) || defined(USE_LIBRETINY) || defined(USE_ZEPHYR)
-  bool main_task_recursion_guard_{false};
+  bool main_task_recursion_guard_{false};  // Guards tx_buffer_ on the main loop
 #ifdef USE_LIBRETINY
   bool non_main_task_recursion_guard_{false};  // Shared guard for all non-main tasks on LibreTiny
 #endif
-  // The guard that protects tx_buffer_ on the main loop, for callers that run on any platform
-  bool &main_loop_recursion_guard_() { return this->main_task_recursion_guard_; }
-#else
-  bool global_recursion_guard_{false};  // Simple global recursion guard for single-task platforms
-  bool &main_loop_recursion_guard_() { return this->global_recursion_guard_; }
-#endif
 
   // Large buffers placed last to keep frequently-accessed member offsets small
   char tx_buffer_[ESPHOME_LOGGER_TX_BUFFER_SIZE + 1];  // +1 for null terminator
@@ -477,9 +466,9 @@ class Logger final : public Component {
   class NonMainTaskRecursionGuard {
    public:
     explicit NonMainTaskRecursionGuard(pthread_key_t key) : key_(key) {
-      pthread_setspecific(key_, reinterpret_cast<void *>(1));
+      pthread_setspecific(this->key_, reinterpret_cast<void *>(1));
     }
-    ~NonMainTaskRecursionGuard() { pthread_setspecific(key_, nullptr); }
+    ~NonMainTaskRecursionGuard() { pthread_setspecific(this->key_, nullptr); }
     NonMainTaskRecursionGuard(const NonMainTaskRecursionGuard &) = delete;
     NonMainTaskRecursionGuard &operator=(const NonMainTaskRecursionGuard &) = delete;
     NonMainTaskRecursionGuard(NonMainTaskRecursionGuard &&) = delete;
@@ -490,40 +479,24 @@ class Logger final : public Component {
   };
 
   // Check if non-main task is already in recursion (via TLS)
-  inline bool HOT is_non_main_task_recursive_() const { return pthread_getspecific(log_recursion_key_) != nullptr; }
+  inline bool HOT is_non_main_task_recursive_() const {
+    return pthread_getspecific(this->log_recursion_key_) != nullptr;
+  }
 
   // Create RAII guard for non-main task recursion
-  inline NonMainTaskRecursionGuard make_non_main_task_guard_() { return NonMainTaskRecursionGuard(log_recursion_key_); }
-
-#elif defined(USE_LIBRETINY) || defined(USE_ZEPHYR)
-  // LibreTiny doesn't have FreeRTOS TLS, so use a simple approach:
-  // - Main task uses dedicated boolean (same as ESP32)
-  // - Non-main tasks share a single recursion guard
-  // This is safe because:
-  // - Recursion from logging within logging is the main concern
-  // - Cross-task "recursion" is prevented by the buffer mutex anyway
-  // - Missing a recursive call from another task is acceptable (falls back to direct output)
-  //
-  // Zephyr use __thread as TLS
-
-  // Check if non-main task is already in recursion
-  inline bool HOT is_non_main_task_recursive_() const { return non_main_task_recursion_guard_; }
-
-  // Create RAII guard for non-main task recursion (uses shared boolean for all non-main tasks)
-  inline RecursionGuard make_non_main_task_guard_() { return RecursionGuard(non_main_task_recursion_guard_); }
-#endif
-
-#if defined(USE_ESPHOME_TASK_LOG_BUFFER) && !(defined(USE_ZEPHYR) && defined(USE_LOGGER_UART_SELECTION_USB_CDC))
-  // Disable loop when task buffer is empty
-  // Zephyr with USB CDC needs loop active to poll port readiness via cdc_loop_()
-  inline void disable_loop_when_buffer_empty_() {
-    // Thread safety note: This is safe even if another task calls enable_loop_soon_any_context()
-    // concurrently. If that happens between our check and disable_loop(), the enable request
-    // will be processed on the next main loop iteration since:
-    // - disable_loop() takes effect immediately
-    // - enable_loop_soon_any_context() sets a pending flag that's checked at loop start
-    this->disable_loop();
+  inline NonMainTaskRecursionGuard make_non_main_task_guard_() {
+    return NonMainTaskRecursionGuard(this->log_recursion_key_);
   }
+
+#elif defined(USE_LIBRETINY)
+  // No FreeRTOS TLS on LibreTiny: all non-main tasks share one guard
+  inline bool HOT is_non_main_task_recursive_() const { return this->non_main_task_recursion_guard_; }
+  inline RecursionGuard make_non_main_task_guard_() { return RecursionGuard(this->non_main_task_recursion_guard_); }
+
+#elif defined(USE_ZEPHYR)
+  // Thread-local guard (__thread)
+  inline bool HOT is_non_main_task_recursive_() const { return non_main_task_recursion_guard; }
+  inline RecursionGuard make_non_main_task_guard_() { return RecursionGuard(non_main_task_recursion_guard); }
 #endif
 };
 extern Logger *global_logger;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
@@ -563,14 +536,7 @@ void log_crash_to_client();
 
 }  // namespace esphome::logger
 
-// Platform-specific inline implementations of write_msg_()
-// Must be included after the Logger class definition is complete
-#if defined(USE_ESP32)
+// ESP32 inline write_msg_(), included after the Logger class definition is complete
+#ifdef USE_ESP32
 #include "logger_esp32.h"
-#elif defined(USE_ESP8266)
-#include "logger_esp8266.h"
-#elif defined(USE_RP2)
-#include "logger_rp2.h"
-#elif defined(USE_LIBRETINY)
-#include "logger_libretiny.h"
 #endif

esphome/components/logger/logger_esp32.cpp

@@ -73,7 +73,7 @@ static void init_usb_serial_jtag() {
 }
 #endif
 
-void init_uart(uart_port_t uart_num, uint32_t baud_rate, int tx_buffer_size) {
+static void init_uart(uart_port_t uart_num, uint32_t baud_rate, int tx_buffer_size) {
   uart_config_t uart_config{};
   uart_config.baud_rate = (int) baud_rate;
   uart_config.data_bits = UART_DATA_8_BITS;
@@ -98,24 +98,23 @@ void init_uart(uart_port_t uart_num, uint32_t baud_rate, int tx_buffer_size) {
 #endif
 }
 
+// get_uart_num() and pre_setup() cast the selection straight to a port
+static_assert(static_cast<int>(UART_SELECTION_UART0) == static_cast<int>(UART_NUM_0) &&
+              static_cast<int>(UART_SELECTION_UART1) == static_cast<int>(UART_NUM_1));
+#ifdef USE_ESP32_VARIANT_ESP32
+static_assert(static_cast<int>(UART_SELECTION_UART2) == static_cast<int>(UART_NUM_2));
+#endif
+
 void Logger::pre_setup() {
   if (this->baud_rate_ > 0) {
-    this->uart_num_ = UART_NUM_0;
     switch (this->uart_) {
       case UART_SELECTION_UART0:
-        this->uart_num_ = UART_NUM_0;
-        init_uart(this->uart_num_, baud_rate_, ESPHOME_LOGGER_TX_BUFFER_SIZE);
-        break;
       case UART_SELECTION_UART1:
-        this->uart_num_ = UART_NUM_1;
-        init_uart(this->uart_num_, baud_rate_, ESPHOME_LOGGER_TX_BUFFER_SIZE);
-        break;
 #ifdef USE_ESP32_VARIANT_ESP32
       case UART_SELECTION_UART2:
-        this->uart_num_ = UART_NUM_2;
-        init_uart(this->uart_num_, baud_rate_, ESPHOME_LOGGER_TX_BUFFER_SIZE);
-        break;
 #endif
+        init_uart(static_cast<uart_port_t>(this->uart_), this->baud_rate_, ESPHOME_LOGGER_TX_BUFFER_SIZE);
+        break;
 #ifdef USE_LOGGER_USB_CDC
       case UART_SELECTION_USB_CDC:
         break;

esphome/components/logger/logger_esp32.h

@@ -19,7 +19,7 @@ inline void HOT Logger::write_msg_(const char *msg, uint16_t len) {
   fwrite(msg, 1, len, stdout);
 #else
   // Regular UART - single write including newline (already in buffer)
-  uart_write_bytes(this->uart_num_, msg, len);
+  uart_write_bytes(this->get_uart_num(), msg, len);
 #endif
 }
 

esphome/components/logger/logger_esp8266.h

@@ -1,13 +0,0 @@
-#pragma once
-
-#ifdef USE_ESP8266
-#include "esphome/core/helpers.h"
-
-namespace esphome::logger {
-
-// Single write with newline already in buffer (added by caller)
-inline void HOT Logger::write_msg_(const char *msg, uint16_t len) { this->hw_serial_->write(msg, len); }
-
-}  // namespace esphome::logger
-
-#endif

esphome/components/logger/logger_libretiny.h

@@ -1,13 +0,0 @@
-#pragma once
-
-#ifdef USE_LIBRETINY
-#include "esphome/core/helpers.h"
-
-namespace esphome::logger {
-
-// Single write with newline already in buffer (added by caller)
-inline void HOT Logger::write_msg_(const char *msg, uint16_t len) { this->hw_serial_->write(msg, len); }
-
-}  // namespace esphome::logger
-
-#endif

esphome/components/logger/logger_rp2.cpp

@@ -55,10 +55,8 @@ const LogString *Logger::get_uart_selection_() {
       return LOG_STR("UART0");
     case UART_SELECTION_UART1:
       return LOG_STR("UART1");
-#ifdef USE_LOGGER_USB_CDC
     case UART_SELECTION_USB_CDC:
       return LOG_STR("USB_CDC");
-#endif
     default:
       return LOG_STR("UNKNOWN");
   }

esphome/components/logger/logger_rp2.h

@@ -1,13 +0,0 @@
-#pragma once
-
-#ifdef USE_RP2
-#include "esphome/core/helpers.h"
-
-namespace esphome::logger {
-
-// Single write with newline already in buffer (added by caller)
-inline void HOT Logger::write_msg_(const char *msg, uint16_t len) { this->hw_serial_->write(msg, len); }
-
-}  // namespace esphome::logger
-
-#endif

esphome/components/logger/logger_zephyr.cpp

@@ -44,7 +44,7 @@ ESPHOME_LOG_TAG(TAG, "logger");
 
 #ifdef USE_LOGGER_UART_SELECTION_USB_CDC
 void Logger::cdc_loop_() {
-  if (this->uart_ != UART_SELECTION_USB_CDC || this->uart_dev_ == nullptr) {
+  if (this->uart_dev_ == nullptr) {
     return;
   }
   static bool opened = false;
@@ -74,7 +74,7 @@ void Logger::cdc_loop_() {
 void Logger::pre_setup() {
 #ifdef CONFIG_SERIAL
   if (this->baud_rate_ > 0) {
-    static const struct device *uart_dev = nullptr;
+    const struct device *uart_dev = nullptr;
     switch (this->uart_) {
       case UART_SELECTION_UART0:  // NOLINT(bugprone-branch-clone)
         uart_dev = DEVICE_DT_GET_OR_NULL(DT_NODELABEL(ESPHOME_LOGGER_UART0_NODE));
@@ -114,14 +114,10 @@ void Logger::pre_setup() {
   char reason_buffer[zephyr::RESET_REASON_BUFFER_SIZE];
   const char *reset_reason = zephyr::get_reset_reason(std::span<char, zephyr::RESET_REASON_BUFFER_SIZE>(reason_buffer));
   ESP_LOGI(TAG, "Reset reason: %s", reset_reason);
-  dump_crash_();
+  this->dump_crash_();
 #endif
-#ifdef USE_CRASH_HANDLER
-#ifdef USE_LOGGER_UART_SELECTION_USB_CDC
   // Nobody reads a USB port this early; cdc_loop_() reports the dump once the port is opened
-  if (this->uart_ == UART_SELECTION_USB_CDC)
-    return;
-#endif
+#if defined(USE_CRASH_HANDLER) && !defined(USE_LOGGER_UART_SELECTION_USB_CDC)
   // Without a UART (baud_rate: 0, or one that did not come up) nothing reaches the console
   if (this->uart_dev_ != nullptr)
     log_crash_to_client();
@@ -158,7 +154,7 @@ const LogString *Logger::get_uart_selection_() {
   }
 }
 
-static const uint8_t REASON_BUF_SIZE = 32;
+static constexpr uint8_t REASON_BUF_SIZE = 32;
 
 static const char *reason_to_str(unsigned int reason, char *buf) {
   switch (reason) {

esphome/components/logger/task_log_buffer_esp32.cpp

@@ -44,19 +44,15 @@ void TaskLogBuffer::release_message_main_loop() {
 
 bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uint16_t line, const char *thread_name,
                                              const char *format, va_list args) {
-  // First, calculate the exact length needed using a null buffer (no actual writing)
+  // Measure on a copy; the caller's va_list formats the text later
   va_list args_copy;
   va_copy(args_copy, args);
-  int ret = vsnprintf(nullptr, 0, format, args_copy);
+  int ret = task_log_cap_length(vsnprintf(nullptr, 0, format, args_copy));
   va_end(args_copy);
-
   if (ret <= 0) {
     return false;  // Formatting error or empty message
   }
-
-  // Calculate actual text length (capped to maximum size)
-  static constexpr size_t MAX_TEXT_SIZE = 255;
-  size_t text_length = (static_cast<size_t>(ret) > MAX_TEXT_SIZE) ? MAX_TEXT_SIZE : ret;
+  uint16_t text_length = ret;
 
   // Calculate total size needed (header + text length + null terminator)
   size_t total_size = sizeof(LogMessage) + text_length + 1;
@@ -69,24 +65,10 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
     return false;  // Failed to acquire memory
   }
 
-  // Set up the message header in the acquired memory
   LogMessage *msg = static_cast<LogMessage *>(acquired_memory);
-  msg->level = level;
-  msg->tag = tag;
-  msg->line = line;
-
-  // Store the thread name now instead of waiting until main loop processing
-  // This avoids crashes if the task completes or is deleted between when this message
-  // is enqueued and when it's processed by the main loop
-  if (thread_name != nullptr) {
-    strncpy(msg->thread_name, thread_name, sizeof(msg->thread_name) - 1);
-    msg->thread_name[sizeof(msg->thread_name) - 1] = '\0';  // Ensure null termination
-  } else {
-    msg->thread_name[0] = '\0';  // Empty string if no thread name
-  }
+  fill_task_log_header(msg, level, tag, line, thread_name);
 
   // Format the message text directly into the acquired memory
-  // We add 1 to text_length to ensure space for null terminator during formatting
   char *text_area = msg->text_data();
   ret = vsnprintf(text_area, text_length + 1, format, args);
 
@@ -96,12 +78,7 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
     return false;
   }
 
-  // Remove trailing newlines
-  while (text_length > 0 && text_area[text_length - 1] == '\n') {
-    text_length--;
-  }
-
-  msg->text_length = text_length;
+  msg->text_length = trim_trailing_newlines(text_area, text_length);
   // Complete the send operation with the acquired memory
   result = xRingbufferSendComplete(this->handle_(), acquired_memory);
 

esphome/components/logger/task_log_buffer_esp32.h

@@ -12,6 +12,8 @@
 #include <freertos/FreeRTOS.h>
 #include <freertos/ringbuf.h>
 
+#include "task_log_message.h"
+
 namespace esphome::logger {
 
 /**
@@ -32,19 +34,7 @@ namespace esphome::logger {
  */
 class TaskLogBuffer {
  public:
-  // Structure for a log message header (text data follows immediately after)
-  struct LogMessage {
-    const char *tag;       // We store the pointer, assuming tags are static
-    char thread_name[16];  // Store thread name directly (only used for non-main threads)
-    uint16_t text_length;  // Length of the message text (up to ~64KB)
-    uint16_t line;         // Source code line number
-    uint8_t level;         // Log level (0-7)
-
-    // Methods for accessing message contents
-    inline char *text_data() { return reinterpret_cast<char *>(this) + sizeof(LogMessage); }
-
-    inline const char *text_data() const { return reinterpret_cast<const char *>(this) + sizeof(LogMessage); }
-  };
+  using LogMessage = TaskLogMessage;
 
   TaskLogBuffer();
   // No destructor: Logger is never destroyed

esphome/components/logger/task_log_buffer_host.cpp

@@ -71,18 +71,8 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
 
   LogMessage &msg = this->slots_[slot_index];
 
-  // Fill in the message header
-  msg.level = level;
-  msg.tag = tag;
-  msg.line = line;
-
-  // Store the thread name now to avoid crashes if thread exits before processing
-  if (thread_name != nullptr) {
-    strncpy(msg.thread_name, thread_name, sizeof(msg.thread_name) - 1);
-    msg.thread_name[sizeof(msg.thread_name) - 1] = '\0';
-  } else {
-    msg.thread_name[0] = '\0';
-  }
+  // Copied now; the thread may exit before processing
+  fill_task_log_header(&msg, level, tag, line, thread_name);
 
   // Format the message text
   int ret = vsnprintf(msg.text, sizeof(msg.text), format, args);
@@ -94,10 +84,7 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
     msg.text_length = static_cast<uint16_t>(std::min(static_cast<size_t>(ret), sizeof(msg.text) - 1));
   }
 
-  // Remove trailing newlines
-  while (msg.text_length > 0 && msg.text[msg.text_length - 1] == '\n') {
-    msg.text_length--;
-  }
+  msg.text_length = trim_trailing_newlines(msg.text, msg.text_length);
   msg.text[msg.text_length] = '\0';
 
   // Commit the slot

esphome/components/logger/task_log_buffer_host.h

@@ -13,6 +13,8 @@
 #include <cstring>
 #include <pthread.h>
 
+#include "task_log_message.h"
+
 namespace esphome::logger {
 
 /**

esphome/components/logger/task_log_buffer_libretiny.cpp

@@ -13,13 +13,6 @@ TaskLogBuffer::TaskLogBuffer() {
   this->mutex_ = xSemaphoreCreateMutex();
 }
 
-TaskLogBuffer::~TaskLogBuffer() {
-  if (this->mutex_ != nullptr) {
-    vSemaphoreDelete(this->mutex_);
-    this->mutex_ = nullptr;
-  }
-}
-
 size_t TaskLogBuffer::available_contiguous_space_() const {
   if (this->head_ >= this->tail_) {
     // head is ahead of or equal to tail
@@ -85,19 +78,15 @@ void TaskLogBuffer::release_message_main_loop() {
 
 bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uint16_t line, const char *thread_name,
                                              const char *format, va_list args) {
-  // First, calculate the exact length needed using a null buffer (no actual writing)
+  // Measure on a copy; the caller's va_list formats the text later
   va_list args_copy;
   va_copy(args_copy, args);
-  int ret = vsnprintf(nullptr, 0, format, args_copy);
+  int ret = task_log_cap_length(vsnprintf(nullptr, 0, format, args_copy));
   va_end(args_copy);
-
   if (ret <= 0) {
     return false;  // Formatting error or empty message
   }
-
-  // Calculate actual text length (capped to maximum size)
-  static constexpr size_t MAX_TEXT_SIZE = 255;
-  size_t text_length = (static_cast<size_t>(ret) > MAX_TEXT_SIZE) ? MAX_TEXT_SIZE : ret;
+  uint16_t text_length = ret;
 
   // Calculate total size needed (header + text length + null terminator)
   size_t total_size = message_total_size(text_length);
@@ -128,17 +117,7 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
 
   // Write message header
   LogMessage *msg = reinterpret_cast<LogMessage *>(this->storage_ + write_pos);
-  msg->level = level;
-  msg->tag = tag;
-  msg->line = line;
-
-  // Store the thread name now to avoid crashes if task is deleted before processing
-  if (thread_name != nullptr) {
-    strncpy(msg->thread_name, thread_name, sizeof(msg->thread_name) - 1);
-    msg->thread_name[sizeof(msg->thread_name) - 1] = '\0';
-  } else {
-    msg->thread_name[0] = '\0';
-  }
+  fill_task_log_header(msg, level, tag, line, thread_name);
 
   // Format the message text directly into the buffer
   char *text_area = msg->text_data();
@@ -150,9 +129,7 @@ bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uin
   }
 
   // Trim before storing so the next message reuses the freed bytes
-  while (text_length > 0 && text_area[text_length - 1] == '\n') {
-    text_length--;
-  }
+  text_length = trim_trailing_newlines(text_area, text_length);
   text_area[text_length] = '\0';
   msg->text_length = text_length;
 

esphome/components/logger/task_log_buffer_libretiny.h

@@ -13,6 +13,8 @@
 #include <semphr.h>
 #include <task.h>
 
+#include "task_log_message.h"
+
 namespace esphome::logger {
 
 /**
@@ -42,25 +44,14 @@ namespace esphome::logger {
  */
 class TaskLogBuffer {
  public:
-  // Structure for a log message header (text data follows immediately after)
-  struct LogMessage {
-    const char *tag;       // We store the pointer, assuming tags are static
-    char thread_name[16];  // Store thread name directly (only used for non-main threads)
-    uint16_t text_length;  // Length of the message text (up to ~64KB)
-    uint16_t line;         // Source code line number
-    uint8_t level;         // Log level (0-7)
-
-    // Methods for accessing message contents
-    inline char *text_data() { return reinterpret_cast<char *>(this) + sizeof(LogMessage); }
-    inline const char *text_data() const { return reinterpret_cast<const char *>(this) + sizeof(LogMessage); }
-  };
+  using LogMessage = TaskLogMessage;
 
   // Padding marker level to indicate wrap-around point (stored in LogMessage.level field)
   // Valid log levels are 0-7, so 0xFF cannot be a real message
   static constexpr uint8_t PADDING_MARKER_LEVEL = 0xFF;
 
   TaskLogBuffer();
-  ~TaskLogBuffer();
+  // No destructor: Logger is never destroyed
 
   // NOT thread-safe - borrow a message from the buffer, only call from main loop
   bool borrow_message_main_loop(LogMessage *&message, uint16_t &text_length);

esphome/components/logger/task_log_buffer_zephyr.cpp

@@ -4,7 +4,7 @@
 
 namespace esphome::logger {
 
-__thread bool non_main_task_recursion_guard_;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+__thread bool non_main_task_recursion_guard;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
 
@@ -29,29 +29,21 @@ TaskLogBuffer::TaskLogBuffer() {
 
 bool TaskLogBuffer::send_message_thread_safe(uint8_t level, const char *tag, uint16_t line, const char *thread_name,
                                              const char *format, va_list args) {
-  // First, calculate the exact length needed using a null buffer (no actual writing)
+  // Measure on a copy; the caller's va_list formats the text later
   va_list args_copy;
   va_copy(args_copy, args);
-  int ret = vsnprintf(nullptr, 0, format, args_copy);
+  int ret = task_log_cap_length(vsnprintf(nullptr, 0, format, args_copy));
   va_end(args_copy);
-
   if (ret <= 0) {
     return false;  // Formatting error or empty message
   }
-
-  // Calculate actual text length (capped to maximum size)
-  static constexpr size_t MAX_TEXT_SIZE = 255;
-  size_t text_length = (static_cast<size_t>(ret) > MAX_TEXT_SIZE) ? MAX_TEXT_SIZE : ret;
+  uint16_t text_length = ret;
   size_t total_size = total_size_in_32bit_words(text_length);
   auto *msg = reinterpret_cast<LogMessage *>(mpsc_pbuf_alloc(&this->log_buffer_, total_size, K_NO_WAIT));
   if (msg == nullptr) {
     return false;
   }
-  msg->level = level;
-  msg->tag = tag;
-  msg->line = line;
-  strncpy(msg->thread_name, thread_name, sizeof(msg->thread_name) - 1);
-  msg->thread_name[sizeof(msg->thread_name) - 1] = '\0';  // Ensure null termination
+  fill_task_log_header(msg, level, tag, line, thread_name);
 
   // Format the message text directly into the acquired memory
   // We add 1 to text_length to ensure space for null terminator during formatting
@@ -90,11 +82,7 @@ bool TaskLogBuffer::borrow_message_main_loop(LogMessage *&message, uint16_t &tex
   // we claimed buffer already, const_cast is safe here
   message = const_cast<LogMessage *>(reinterpret_cast<const LogMessage *>(this->current_token_));
 
-  text_length = message->text_length;
-  // Remove trailing newlines
-  while (text_length > 0 && message->text_data()[text_length - 1] == '\n') {
-    text_length--;
-  }
+  text_length = trim_trailing_newlines(message->text_data(), message->text_length);
 
   return true;
 }

esphome/components/logger/task_log_buffer_zephyr.h

@@ -6,12 +6,14 @@
 #include "esphome/core/helpers.h"
 #include <zephyr/sys/mpsc_pbuf.h>
 
+#include "task_log_message.h"
+
 namespace esphome::logger {
 
 // "0x" + 2 hex digits per byte + '\0'
 static constexpr size_t MAX_POINTER_REPRESENTATION = 2 + sizeof(void *) * 2 + 1;
 
-extern __thread bool non_main_task_recursion_guard_;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+extern __thread bool non_main_task_recursion_guard;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
 
@@ -34,7 +36,6 @@ class TaskLogBuffer {
     inline char *text_data() { return reinterpret_cast<char *>(this) + sizeof(LogMessage); }
   };
   TaskLogBuffer();
-  ~TaskLogBuffer() = default;
 
   // Check if there are messages ready to be processed using an atomic counter for performance
   inline bool HOT has_messages() { return mpsc_pbuf_is_pending(&this->log_buffer_); }

esphome/components/logger/task_log_message.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+
+#ifdef USE_ESPHOME_TASK_LOG_BUFFER
+#include <cstdarg>
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <cstring>
+
+namespace esphome::logger {
+
+#if defined(USE_ESP32) || defined(USE_LIBRETINY)
+// Header of a variable-size task log message; the text follows it
+struct TaskLogMessage {
+  const char *tag;       // We store the pointer, assuming tags are static
+  char thread_name[16];  // Copied, the task may be gone before the main loop reads it
+  uint16_t text_length;
+  uint16_t line;
+  uint8_t level;
+
+  inline char *text_data() { return reinterpret_cast<char *>(this) + sizeof(TaskLogMessage); }
+};
+#endif
+
+#if defined(USE_ESP32) || defined(USE_LIBRETINY) || defined(USE_ZEPHYR)
+static constexpr int TASK_LOG_MAX_TEXT_SIZE = 255;
+
+inline int task_log_cap_length(int ret) { return ret > TASK_LOG_MAX_TEXT_SIZE ? TASK_LOG_MAX_TEXT_SIZE : ret; }
+#endif
+
+template<typename Message>
+inline void fill_task_log_header(Message *msg, uint8_t level, const char *tag, uint16_t line, const char *thread_name) {
+  msg->level = level;
+  msg->tag = tag;
+  msg->line = line;
+  if (thread_name != nullptr) {
+    strncpy(msg->thread_name, thread_name, sizeof(msg->thread_name) - 1);
+    msg->thread_name[sizeof(msg->thread_name) - 1] = '\0';
+  } else {
+    msg->thread_name[0] = '\0';
+  }
+}
+
+inline uint16_t trim_trailing_newlines(const char *text, uint16_t length) {
+  while (length > 0 && text[length - 1] == '\n')
+    length--;
+  return length;
+}
+
+}  // namespace esphome::logger
+
+#endif  // USE_ESPHOME_TASK_LOG_BUFFER

tests/component_tests/logger/test_logger.py

@@ -168,23 +168,46 @@ def test_log_v2_only_on_native_toolchain(
 
 
 @pytest.mark.parametrize(
-    ("config", "usb_cdc"),
+    ("config", "expected"),
     [
-        pytest.param("test_logger_rp2_usb_cdc.yaml", True, id="usb_cdc"),
-        pytest.param("test_logger_rp2_uart0.yaml", False, id="uart0"),
+        pytest.param("test_logger_rp2_usb_cdc.yaml", {"USB_CDC"}, id="rp2_usb_cdc"),
+        pytest.param("test_logger_rp2_uart0.yaml", set(), id="rp2_uart0"),
+        pytest.param("test_logger_esp32_usb_cdc.yaml", {"USB_CDC"}, id="esp32_usb_cdc"),
+        pytest.param(
+            "test_logger_esp32_usb_serial_jtag.yaml",
+            {"USB_SERIAL_JTAG"},
+            id="esp32_usb_serial_jtag",
+        ),
+        pytest.param("test_logger_nrf52_usb_cdc.yaml", {"USB_CDC"}, id="nrf52_usb_cdc"),
+        # Zephyr polls the USB port only when it logs there
+        pytest.param(
+            "test_logger_nrf52_usb_cdc_no_serial.yaml", set(), id="nrf52_no_serial"
+        ),
     ],
 )
-def test_rp2_usb_cdc_selection_define(
+def test_uart_selection_defines(
     generate_main: Callable[[str | Path], str],
     config: str,
-    usb_cdc: bool,
+    expected: set[str],
 ) -> None:
-    """The USB CDC crash replay only compiles in when the logger uses USB CDC."""
+    """USB ports get a selection define, which gates their port code and crash replay."""
     generate_main(f"tests/component_tests/logger/{config}")
 
+    prefix = "USE_LOGGER_UART_SELECTION_"
+    assert {
+        d.name.removeprefix(prefix) for d in CORE.defines if d.name.startswith(prefix)
+    } == expected
+
+
+def test_log_listener_slots_count_every_listener(
+    generate_main: Callable[[str | Path], str],
+) -> None:
+    """Two on_message triggers and the API each take a slot."""
+    generate_main("tests/component_tests/logger/test_logger_listeners.yaml")
+
     assert (
-        "USE_LOGGER_UART_SELECTION_USB_CDC" in {d.name for d in CORE.defines}
-    ) is usb_cdc
+        str({d.name: d.value for d in CORE.defines}["ESPHOME_LOG_MAX_LISTENERS"]) == "3"
+    )
 
 
 @pytest.mark.parametrize(

tests/component_tests/logger/test_logger_esp32_usb_cdc.yaml

@@ -0,0 +1,11 @@
+---
+esphome:
+  name: test
+
+esp32:
+  variant: esp32s3
+  framework:
+    type: esp-idf
+
+logger:
+  hardware_uart: USB_CDC

tests/component_tests/logger/test_logger_esp32_usb_serial_jtag.yaml

@@ -0,0 +1,11 @@
+---
+esphome:
+  name: test
+
+esp32:
+  variant: esp32c3
+  framework:
+    type: esp-idf
+
+logger:
+  hardware_uart: USB_SERIAL_JTAG

tests/component_tests/logger/test_logger_listeners.yaml

@@ -0,0 +1,23 @@
+---
+esphome:
+  name: test
+
+esp32:
+  variant: esp32
+  framework:
+    type: esp-idf
+
+wifi:
+  ssid: test
+  password: testtesttest
+
+api:
+
+logger:
+  on_message:
+    - level: ERROR
+      then:
+        - lambda: "(void) message;"
+    - level: WARN
+      then:
+        - lambda: "(void) message;"

tests/component_tests/logger/test_logger_nrf52_usb_cdc.yaml

@@ -0,0 +1,10 @@
+---
+esphome:
+  name: test
+
+nrf52:
+  board: adafruit_itsybitsy_nrf52840
+  bootloader: adafruit_nrf52_sd140_v6
+
+logger:
+  hardware_uart: USB_CDC

tests/component_tests/logger/test_logger_nrf52_usb_cdc_no_serial.yaml

@@ -0,0 +1,11 @@
+---
+esphome:
+  name: test
+
+nrf52:
+  board: adafruit_itsybitsy_nrf52840
+  bootloader: adafruit_nrf52_sd140_v6
+
+logger:
+  hardware_uart: USB_CDC
+  baud_rate: 0

tests/components/logger/task_log_message_test.cpp

@@ -0,0 +1,54 @@
+#include <gtest/gtest.h>
+#include <cstring>
+
+#include "esphome/core/defines.h"
+
+// The cap and message header are compiled only for platforms with a task log buffer
+#define USE_LIBRETINY
+#ifndef USE_ESPHOME_TASK_LOG_BUFFER
+#define USE_ESPHOME_TASK_LOG_BUFFER
+#endif
+#include "esphome/components/logger/task_log_message.h"
+#undef USE_LIBRETINY
+
+namespace esphome::logger::testing {
+
+TEST(TaskLogMessageTest, CapLengthStopsAt255) {
+  EXPECT_EQ(task_log_cap_length(0), 0);
+  EXPECT_EQ(task_log_cap_length(255), 255);
+  EXPECT_EQ(task_log_cap_length(256), 255);
+  EXPECT_EQ(task_log_cap_length(1000), 255);
+}
+
+TEST(TaskLogMessageTest, HeaderCopiesFieldsAndThreadName) {
+  TaskLogMessage msg{};
+  fill_task_log_header(&msg, 3, "tag", 42, "worker");
+  EXPECT_EQ(msg.level, 3);
+  EXPECT_STREQ(msg.tag, "tag");
+  EXPECT_EQ(msg.line, 42);
+  EXPECT_STREQ(msg.thread_name, "worker");
+}
+
+TEST(TaskLogMessageTest, HeaderNullThreadNameIsEmpty) {
+  TaskLogMessage msg{};
+  std::memset(msg.thread_name, 'x', sizeof(msg.thread_name));
+  fill_task_log_header(&msg, 1, "tag", 1, nullptr);
+  EXPECT_STREQ(msg.thread_name, "");
+}
+
+TEST(TaskLogMessageTest, HeaderTruncatesLongThreadName) {
+  TaskLogMessage msg{};
+  fill_task_log_header(&msg, 1, "tag", 1, "a_thread_name_longer_than_sixteen");
+  EXPECT_EQ(std::strlen(msg.thread_name), sizeof(msg.thread_name) - 1);
+  EXPECT_EQ(std::strncmp(msg.thread_name, "a_thread_name_l", sizeof(msg.thread_name) - 1), 0);
+}
+
+TEST(TaskLogMessageTest, TrimTrailingNewlines) {
+  EXPECT_EQ(trim_trailing_newlines("", 0), 0);
+  EXPECT_EQ(trim_trailing_newlines("abc", 3), 3);
+  EXPECT_EQ(trim_trailing_newlines("abc\n\n", 5), 3);
+  EXPECT_EQ(trim_trailing_newlines("\n\n\n", 3), 0);
+  EXPECT_EQ(trim_trailing_newlines("a\nb", 3), 3);
+}
+
+}  // namespace esphome::logger::testing