refactor: extract shared logic from Arcjet and ArcjetSync into helper…

[qw-in]

… functions

The async Arcjet and sync ArcjetSync classes had near-identical implementations of protect(), with ~300 lines duplicated between them. The arcjet() and arcjet_sync() factory functions were similarly duplicated.

Extract 9 shared helper functions that both clients now call:

• _validate_ip_config: IP/proxy configuration validation
• _prepare_protect_context: context coercion, email/message validation, token-bucket defaulting, extra-field merging, characteristic flattening
• _build_decide_request: assemble DecideRequest protobuf
• _build_cache_hit_report: build ReportRequest for cache hits
• _log_cache_hit_report: debug logging for cache-hit reports
• _handle_transport_error: transport error → Decision or raise
• _handle_invalid_response: invalid response → Decision or raise
• _finalize_decision: wrap response, cache, log timing
• _compute_client_kwargs: shared factory function kwargs

Each protect() method is reduced from ~300 lines to ~60 lines of unique async/sync-specific code. Add 62 new tests in test_client_helpers.py covering all extracted helpers using real protobuf types (no monkeypatched stubs).

[qw-in]

Tried to reduce some of the duplication between the sync & async code paths. Not sure if its better but was quite low lift to get something out

[Copilot]

Pull request overview

Refactors the Arcjet Python SDK client implementation by extracting duplicated async/sync protect() and factory logic into shared internal helper functions, and adds direct unit tests for those helpers using real protobuf types.

Changes:

• Added several shared internal helper functions to src/arcjet/client.py (context preparation, request/report building, error handling, decision finalization, shared factory kwargs).
• Updated Arcjet.protect(), ArcjetSync.protect(), arcjet(), and arcjet_sync() to call the new helpers instead of duplicating logic.
• Added a new tests/test_client_helpers.py test module covering the extracted helpers.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/arcjet/client.py	Introduces shared helper functions and rewires async/sync clients + factories to use them.
tests/test_client_helpers.py	Adds focused unit tests for the extracted client helper functions using real protobuf types.

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[Copilot]

Top-level imports are split into two separate blocks (second block starts mid-file). Ruff is configured to enforce import formatting (isort via rule set "I"), so this will likely fail linting. Please merge these into a single import section at the top of the module (and keep ordering consistent).

[qw-in]

I took too long and don't think its worth it given the code changes