`CountDocumentsAsyncTest`, `WriteDocumentsAsyncTest`, `WriteDocumentsAsyncTest`

[davidsbatista]

NOTES:

• Tests should be written into haystack/testing/document_store_async.py
• Use async def for all test methods
• Decorate each test method with @pytest.mark.asyncio
• Rely on an async-compatible document_store fixture (to be provided by the concrete test class in each integration)
• Use await on all *_async() calls
• Use write_documents_async / count_documents_async in setup steps (not the sync variants), so the full async path is exercised end-to-end
• Open the PR to the async-mixin-tests feature branch

CountDocumentsAsyncTest

Mirrors: CountDocumentsTest

Test	Description
test_count_empty_async	await count_documents_async() returns 0 on empty store
test_count_not_empty_async	After writing 3 docs via write_documents_async, count_documents_async() returns 3

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WriteDocumentsAsyncTest(AssertDocumentsEqualMixin)

Mirrors: WriteDocumentsTest

Test	Description
test_write_documents_async	Abstract — raise NotImplementedError with a message; concrete classes must override this
test_write_documents_duplicate_fail_async	Writing same doc twice with DuplicatePolicy.FAIL raises DuplicateDocumentError on second write
test_write_documents_duplicate_skip_async	Second write of same doc with DuplicatePolicy.SKIP returns 0
test_write_documents_duplicate_overwrite_async	DuplicatePolicy.OVERWRITE updates content; verify via filter_documents_async
test_write_documents_invalid_input_async	Passing ["not a document"] or a plain string raises ValueError

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DeleteDocumentsAsyncTest

Mirrors: DeleteDocumentsTest

Test	Description
test_delete_documents_async	Write 1 doc, delete it by id, count_documents_async() returns 0
test_delete_documents_empty_document_store_async	delete_documents_async(["non_existing_id"]) on empty store doesn't raise
test_delete_documents_non_existing_document_async	Delete non-existing id from a 1-doc store; count stays at 1