esphome/tests/integration/fixtures/api_string_lambda.yaml

esphome:
  name: api-string-lambda-test
host:

api:
  actions:
    # Service that tests string lambda functionality
    - action: test_string_lambda
      variables:
        input_string: string
      then:
        # Log the input to verify service was called
        - logger.log:
            format: "Service called with string: %s"
            args: [input_string.c_str()]

        # This is the key test - using a lambda that returns x.c_str()
        # where x is already a string. This would fail to compile in 2025.7.0b5
        # with "no matching function for call to 'to_string(std::string)'"
        # This is the exact case from issue #9539
        - homeassistant.tag_scanned: !lambda 'return input_string.c_str();'

        # Also test with homeassistant.event to verify our fix works with data fields
        - homeassistant.event:
            event: esphome.test_string_lambda
            data:
              value: !lambda 'return input_string.c_str();'

    # Service that tests int lambda functionality
    - action: test_int_lambda
      variables:
        input_number: int
      then:
        # Log the input to verify service was called
        - logger.log:
            format: "Service called with int: %d"
            args: [input_number]

        # Test that int lambdas still work correctly with to_string
        # The TemplatableStringValue should automatically convert int to string
        - homeassistant.event:
            event: esphome.test_int_lambda
            data:
              value: !lambda 'return input_number;'

    # Service that tests float lambda functionality
    - action: test_float_lambda
      variables:
        input_float: float
      then:
        # Log the input to verify service was called
        - logger.log:
            format: "Service called with float: %.2f"
            args: [input_float]

        # Test that float lambdas still work correctly with to_string
        # The TemplatableStringValue should automatically convert float to string
        - homeassistant.event:
            event: esphome.test_float_lambda
            data:
              value: !lambda 'return input_float;'

    # Service that tests char* lambda functionality (e.g., from itoa or sprintf)
    - action: test_char_ptr_lambda
      variables:
        input_number: int
        input_string: string
      then:
        # Log the input to verify service was called
        - logger.log:
            format: "Service called with number for char* test: %d"
            args: [input_number]

        # Test that char* lambdas work correctly
        # This would fail in issue #9628 with "invalid conversion from 'char*' to 'long long unsigned int'"
        - homeassistant.event:
            event: esphome.test_char_ptr_lambda
            data:
              # Test snprintf returning char*
              decimal_value: !lambda 'static char buffer[20]; snprintf(buffer, sizeof(buffer), "%d", input_number); return buffer;'
              # Test strdup returning char* (dynamically allocated)
              string_copy: !lambda 'return strdup(input_string.c_str());'
              # Test string literal (const char*)
              literal: !lambda 'return "test literal";'

logger:
  level: DEBUG