Files
esphome/tests/components
J. Nick Koston abcd89cd1f [wifi] Avoid .rodata RAM cost for ManualIP on ESP8266
On ESP8266, .rodata is mapped to DRAM (RAM), not flash. When
StructInitializer is used with all compile-time constant fields,
the compiler places the entire struct as a const blob in .rodata,
silently consuming ~20 bytes of RAM.

Switch to field-by-field assignment on ESP8266 so the IP address
values are encoded as immediate operands in flash instructions
instead of a .rodata blob. Other platforms continue to use the
aggregate initializer since their .rodata is flash-mapped.
2026-02-23 16:06:28 -06:00
..
2026-01-29 22:48:16 -05:00
2025-11-30 23:27:10 -05:00
2025-09-26 08:53:21 +12:00
2025-11-23 21:25:24 -06:00
2025-11-03 18:29:30 -06:00

How to write C++ ESPHome unit tests

  1. Locate the folder with your component or create a new one with the same name as the component.
  2. Write the tests. You can add as many .cpp and .h files as you need to organize your tests.

IMPORTANT: wrap all your testing code in a unique namespace to avoid linker collisions when compiling testing binaries that combine many components. By convention, this unique namespace is esphome::component::testing (where "component" is the component under test), for example: esphome::uart::testing.

Running component unit tests

(from the repository root)

./script/cpp_unit_test.py component1 component2 ...

The above will compile and run the provided components and their tests.

To run all tests, you can invoke cpp_unit_test.py with the special --all flag:

./script/cpp_unit_test.py --all

To run a specific test suite, you can provide a Google Test filter:

GTEST_FILTER='UART*' ./script/cpp_unit_test.py uart modbus

The process will return 0 for success or nonzero for failure. In case of failure, the errors will be printed out to the console.