fix: make APIBudget honor maximum_attempts_to_acquire exactly

[devin-ai-integration]

Overview

👉 TL;DR: The rate limiter's retry loop made one fewer attempt than configured, so with a single allowed attempt it never checked the rate limit at all and let calls through even when the budget was exhausted. It also slept once more than necessary before giving up. Specifically, APIBudget._do_acquire now iterates range(1, maximum_attempts_to_acquire + 1), breaks before sleeping on the final failed attempt, and APIBudget.__init__ rejects maximum_attempts_to_acquire < 1 with a ValueError.

Resolves https://github.com/airbytehq/airbyte-internal-issues/issues/17247:

• https://github.com/airbytehq/airbyte-internal-issues/issues/17247

Part of epic https://github.com/airbytehq/airbyte-internal-issues/issues/17243.

Changes

• APIBudget._do_acquire: loop bound range(1, n) -> range(1, n + 1) so exactly n try_acquire calls are made; break after the last failed attempt so block=True no longer sleeps for time_to_wait before raising.
• APIBudget.__init__: raise ValueError when maximum_attempts_to_acquire < 1.
• New TestAPIBudgetMaximumAttempts tests: exhausted policy + n=1 raises CallRateLimitHit (blocking and non-blocking); try_acquire is called exactly n times with n-1 sleeps for n in {1, 2, 5}; values < 1 rejected.

Reproduction

Before the fix, with an exhausted FixedWindowCallRatePolicy(call_limit=1):

APIBudget([policy], maximum_attempts_to_acquire=1).acquire_call(req, block=False)  # returned silently
APIBudget([policy], maximum_attempts_to_acquire=2).acquire_call(req, block=False)  # raised CallRateLimitHit

Risks

• Behavior change for the default (100000) is one extra attempt (100000 vs 99999); the only known external caller passing this argument is source-slack, which uses the default.
• Not a breaking change; no public interface changed.

Test plan

• poetry run pytest unit_tests/sources/streams/test_call_rate.py -q (45 passed; the 3 new n>=2 count tests fail on main without the fix)
• poetry run ruff check ., poetry run ruff format --check ., poetry run mypy --config-file mypy.ini airbyte_cdk/sources/streams/call_rate.py

Requested via /ai-fix on the linked issue (triage session: https://app.devin.ai/sessions/33bc7ef3d07c40578437ec2c41099b62).

Link to Devin session: https://app.devin.ai/sessions/55032d81326149dcba6a546fb345a1d8
Open in Devin Desktop: https://app.devin.ai/desktop/session/55032d81326149dcba6a546fb345a1d8?variant=devin

[devin-ai-integration]

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Pull request overview

Updates APIBudget to honor configured retry counts, avoid unnecessary final sleeps, and reject invalid attempt values.

Changes:

• Corrects retry-loop counting and final-attempt behavior.
• Validates maximum_attempts_to_acquire >= 1.
• Adds focused tests for retries, exhaustion, and validation.

File summaries

File	Description
unit_tests/sources/streams/test_call_rate.py	Adds coverage for maximum-attempt behavior.
airbyte_cdk/sources/streams/call_rate.py	Updates retry logic and input validation.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

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[github-actions]

PyTest Results (Full)

4 398 tests  +7   4 386 ✅ +7   8m 29s ⏱️ - 5m 32s
    1 suites ±0      12 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit 6c3c480. ± Comparison against base commit 96a7c0a.

[github-actions]

PyTest Results (Fast)

4 395 tests  +7   4 383 ✅ +7   9m 35s ⏱️ -3s
    1 suites ±0      12 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit 6c3c480. ± Comparison against base commit 96a7c0a.