Run post scripts for factory binaries for flashing (#3003)

Co-authored-by: Oxan van Leeuwen <oxan@oxanvanleeuwen.nl>

esphome/components/esp8266/__init__.py

@@ -1,4 +1,5 @@
 import logging
+import os
 
 from esphome.const import (
     CONF_BOARD,
@@ -14,6 +15,7 @@ from esphome.const import (
 from esphome.core import CORE, coroutine_with_priority
 import esphome.config_validation as cv
 import esphome.codegen as cg
+from esphome.helpers import copy_file_if_changed
 
 from .const import CONF_RESTORE_FROM_FLASH, KEY_BOARD, KEY_ESP8266, esp8266_ns
 from .boards import ESP8266_FLASH_SIZES, ESP8266_LD_SCRIPTS
@@ -158,6 +160,8 @@ async def to_code(config):
     cg.add_define("ESPHOME_BOARD", config[CONF_BOARD])
     cg.add_define("ESPHOME_VARIANT", "ESP8266")
 
+    cg.add_platformio_option("extra_scripts", ["post:post_build.py"])
+
     conf = config[CONF_FRAMEWORK]
     cg.add_platformio_option("framework", "arduino")
     cg.add_build_flag("-DUSE_ARDUINO")
@@ -210,3 +214,14 @@ async def to_code(config):
 
         if ld_script is not None:
             cg.add_platformio_option("board_build.ldscript", ld_script)
+
+
+# Called by writer.py
+def copy_files():
+
+    dir = os.path.dirname(__file__)
+    post_build_file = os.path.join(dir, "post_build.py")
+    copy_file_if_changed(
+        post_build_file,
+        CORE.relative_build_path("post_build.py"),
+    )

esphome/components/esp8266/post_build.py

@@ -0,0 +1,15 @@
+import shutil
+
+# pylint: disable=E0602
+Import("env")  # noqa
+
+
+def esp8266_copy_factory_bin(source, target, env):
+    firmware_name = env.subst("$BUILD_DIR/${PROGNAME}.bin")
+    new_file_name = env.subst("$BUILD_DIR/${PROGNAME}-factory.bin")
+
+    shutil.copyfile(firmware_name, new_file_name)
+
+
+# pylint: disable=E0602
+env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", esp8266_copy_factory_bin)  # noqa