refactor: Rework legacy filters embedding tests and remove numpy dependency #635

	name: Verify preview imports only preview

	on:
	pull_request:
	types:
	- opened
	- reopened
	- synchronize
	- ready_for_review
	paths:
	- "haystack/preview/**.py"

	jobs:
	verify-imports:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v4
	with:
	# With the default value of 1, there are corner cases where tj-actions/changed-files
	# fails with a `no merge base` error
	fetch-depth: 0

	- name: Get changed files
	id: files
	uses: tj-actions/changed-files@v40
	with:
	files: \|
	haystack/preview/**.py

	- name: Check imports
	shell: python
	run: \|
	import re
	regex = r"^(from haystack\|import haystack)(?!\.preview\| import preview)(.*)"

	changed_files = "${{ steps.files.outputs.all_changed_files }}".split()
	matches = {}
	for path in changed_files:
	with open(path, "r") as f:
	file_matches = []
	for line in f.readlines():
	file_matches.extend(re.finditer(regex, line.strip()))
	if file_matches:
	matches[path] = file_matches

	for path, match in matches.items():
	print(f"Bad imports in file '{path}'")
	for m in match:
	print(m.group())
	print()

	if matches:
	print("::error:: Imports in haystack.preview can only import from haystack.preview")
	import sys; sys.exit(1)

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