* Deprecate spider args of spider middleware methods.
* Deprecate the spider arg of pipeline process_item().
* Fix a typing issue.
* Deprecate the spider arg of pipeline {open,close}_spider().
* Cleanup.
* Update docs.
* Add pragma: no cover to some deprecated code.
* More tests.
* More tests.
* More tests.
* Simplify _process_parallel().
* fix issue 4175 - Scrapy does not use a non-zero exit code when pipeline's open_spider throws the exception
* remove extra blank lines
* remove redundant code
* remove blank line at end of file
* more suitable naming for response and make if-condition shorter
* avoid error - AttributeError: 'Deferred' object has no attribute 'result'
* use getattr to make code concisely
* add test
* remove useless file
* modify test class name
* remove unneccessary files
* Fix Flake8-reported issue
* fix these items which are suggested by Gallaecio
・Sort those imports at tests/test_cmdline_crawl_with_pipeline/__init__.py
・Remove the unused setUp method.
・Remove comments generated by Scrapy’s project generation tool.
・Remove the [deploy] section from the scrapy.cfg file (I don’t think it’s needed here)
・Remove BOT_NAME and NEWSPIDER_MODULE from settings.py (I think there are not needed either, although I’m less sure about NEWSPIDER_MODULE)
* have to reserve BOT_NAME, SPIDER_MODULES in settings.py
* Remove unneeded empty lines
* Empty __init__.py file with unneeded comments
* Remove an unneeded empty line at the end
* Remove unneeed empty line from __init__.py file
* Update __init__.py
* Update __init__.py
* Update exception.py
* Update normal.py
* Update __init__.py
* Update __init__.py
* fix W391 blank line at end of file
Co-authored-by: Adrián Chaves <adrian@chaves.io>