refactor: add enqueue links filter iterator

[Mantisus]

Description

• The goal of the refactoring is to create a new helper function to check EnqueueLinksKwargs, for use elsewhere in the code. The new function works as an iterator, to better fit the application as a filter.
• Also updated related functions that currently have EnqueueLinksKwargs check logic: extract_links and _commit_request_handler_result.

[Copilot]

Pull Request Overview

Refactors link extraction and enqueue logic by introducing a reusable filter iterator for EnqueueLinksKwargs and centralizing URL normalization.

• Added _enqueue_links_filter_iterator and _convert_url_to_request_iterator helpers to streamline link filtering and conversion.
• Updated Playwright and HTTP crawler extract_links to use to_absolute_url_iterator and the new filter iterator, removing inline normalization logic.
• Removed duplicate enqueue helper functions and legacy URL conversion code across crawlers.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/crawlee/crawlers/_playwright/_playwright_crawler.py	Replaced inline URL normalization and filtering in extract_links with to_absolute_url_iterator and _enqueue_links_filter_iterator, and removed the old enqueue helper.
src/crawlee/crawlers/_basic/_basic_crawler.py	Introduced _enqueue_links_filter_iterator, _convert_url_to_request_iterator, updated enqueue logic, and dropped duplicate code.
src/crawlee/crawlers/_abstract_http/_abstract_http_crawler.py	Updated HTTP extract_links to leverage to_absolute_url_iterator and the new filter iterator, removing old filtering logic.
src/crawlee/_utils/urls.py	Added to_absolute_url_iterator helper for converting streams of URLs to absolute.

Comments suppressed due to low confidence (2)

src/crawlee/crawlers/_basic/_basic_crawler.py:943

• The function references urlparse but it is not imported in this file. Add from urllib.parse import urlparse to prevent a NameError.

parsed_origin_url = urlparse(origin_url)

src/crawlee/crawlers/_basic/_basic_crawler.py:1181

• is_url_absolute and convert_to_absolute_url are used here but not imported. Add from crawlee._utils.urls import is_url_absolute, convert_to_absolute_url to the top of the file.

elif isinstance(url, str) and not is_url_absolute(url):

[vdusek]

Thanks to this change you were able to consolidate _create_enqueue_links_function from abstract http crawler and pw crawler to a single method in basic crawler, am I correct?

[Mantisus]

Thanks to this change you were able to consolidate _create_enqueue_links_function from abstract http crawler and pw crawler to a single method in basic crawler, am I correct?

Not quite. I moved _create_enqueue_links_function to the basic crawler, as this logic had already been consolidated. And it avoided code duplication.

The main purpose of PR is related to #1213 (comment), to localize checks for EnqueueLinksKwargs in one function.