[data] Use ranges in test_operator_fusion.py

[omatthew98]

Description

We are using read_parquet in two of our tests in test_operator_fusion.py, this switches those to use range to make the tests less brittle.

Related issues

Link related issues: "Fixes #1234", "Closes #1234", or "Related to #1234".

Additional information

Optional: Add implementation details, API changes, usage examples, screenshots, etc.

[gemini-code-assist]

Code Review

This pull request refactors two tests in test_operator_fusion.py to use ray.data.range instead of ray.data.read_parquet. This is a great improvement as it makes the tests more robust and less brittle by removing the dependency on file I/O. The changes are correct and align with the goal of improving test quality. I've added a couple of minor suggestions to improve variable naming for better readability. Additionally, as a minor follow-up, the temp_dir fixture is now unused in test_read_with_map_batches_fused_successfully and test_map_batches_with_batch_size_specified_fusion and could be removed from their signatures for better code clarity.

[gemini-code-assist]

For better readability and maintainability, consider using a more descriptive variable name instead of n. For example, num_rows would make the purpose of the variable clearer.

Suggested change

	n = 10
	ds = ray.data.range(n)
	num_rows = 10
	ds = ray.data.range(num_rows)

[gemini-code-assist]

For better readability and maintainability, consider using a more descriptive variable name instead of n. For example, num_rows would make the purpose of the variable clearer.

Suggested change

	n = 10
	ds = ray.data.range(n)
	num_rows = 10
	ds = ray.data.range(num_rows)

[bveeramani]

Nit: Minimally passing tests is a good practice because it can make the intent of the test more clear.

Suggested change

	n = 10
	ds = ray.data.range(n)
	ds = ray.data.range(1)