Add missing test coverage for rate-limit and global state management

[Vedant-code]

Overview

PR #3 added a solid test foundation with 9 tests, but left some critical paths untested. This issue tracks follow-up tests to improve coverage of rate-limit handling, global state management, and edge cases.

Missing Test Coverage

1. retry-after header priority in wait_for_rate_limit (High Priority)

The production code in main.py lines 19-24 prioritizes the Retry-After header over X-RateLimit-Reset, but no test validates this behavior:

retry_after = response.headers.get("retry-after")
if retry_after and retry_after.isdigit():
    wait = int(retry_after) + 2

Missing test: test_retry_after_header_takes_priority_over_reset — verify that when both headers are present, Retry-After is used.

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2. Global state pollution risk (High Priority)

The _last_reset_time global variable is never reset between tests. If tests run in different orders or if one test sets the global state, subsequent tests may fail.

Current state:

# main.py
_last_reset_time: int = 0  # global, never reset in tests

Missing fixture: Create a pytest fixture that resets _last_reset_time to 0 before each test:

@pytest.fixture(autouse=True)
def reset_rate_limit_state(monkeypatch):
    """Reset global rate-limit state before each test."""
    import main
    monkeypatch.setattr(main, "_last_reset_time", 0)

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3. _check_rate_limit_before_request() function (High Priority)

This function manages the cached rate-limit state and is called on every request, but has zero coverage.

Code path (main.py lines 35-42):

def _check_rate_limit_before_request():
    """Sleep until the cached rate-limit reset time, if we know one is pending."""
    global _last_reset_time
    now = int(time.time())
    if _last_reset_time > now:
        wait = _last_reset_time - now + 2
        print(...)
        time.sleep(wait)

Missing test: test_check_rate_limit_before_request_waits_when_time_in_future — verify that the function sleeps until the cached reset time expires.

Missing test: test_check_rate_limit_before_request_skips_when_time_expired — verify that it skips sleep when reset time is in the past.

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4. Success response with zero remaining quota (Medium Priority)

When a 200 response arrives with X-RateLimit-Remaining: 0, the code should preemptively cache the reset time for the next request (lines 53-58):

if remaining is not None and int(remaining) == 0 and reset_ts is not None:
    _last_reset_time = int(reset_ts)
    print("Rate limit will be exhausted...")

Missing test: test_success_with_zero_remaining_caches_reset_time — verify the cache is updated so the next request will wait.

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5. Deduplication and PR filtering in integration test (Medium Priority)

test_produces_output_file doesn't validate the actual parsing logic. Line 153 filters out duplicates and pull requests:

if issue["id"] in seen_ids or "pull_request" in issue:
    continue

Missing test: test_deduplication_filters_duplicate_and_pr_issues — verify duplicate issues and PR results are filtered from output.

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6. Timeout vs. ConnectionError backoff differentiation (Medium Priority)

The code has different retry delays:

• Timeout (line 70): 5s between retries
• ConnectionError (line 73): 10s between retries

Currently there's only one combined test. Should have separate tests to ensure backoff strategy is correct.

Missing tests:

• test_timeout_uses_5s_backoff
• test_connection_error_uses_10s_backoff

---

7. Polite delay between pages and queries (Low Priority)

Lines 180 & 194 have time.sleep(6) calls that should be validated. A future refactor could accidentally remove these.

Optional test: Verify time.sleep is called with the correct delays during pagination and between queries.

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8. Fixture cleanup: empty_env needs yield (Low Priority)

The empty_env fixture in tests/conftest.py doesn't have a yield statement, so it doesn't properly execute the test.

Fix:

@pytest.fixture
def empty_env(monkeypatch):
    """Remove GITHUB_TOKEN so the unauthenticated path is exercised."""
    monkeypatch.delenv("GITHUB_TOKEN", raising=False)
    yield  # <-- missing

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Acceptance Criteria

• test_retry_after_header_takes_priority_over_reset added and passing
• reset_rate_limit_state fixture added and applied to all tests
• test_check_rate_limit_before_request_waits_when_time_in_future added and passing
• test_check_rate_limit_before_request_skips_when_time_expired added and passing
• test_success_with_zero_remaining_caches_reset_time added and passing
• test_deduplication_filters_duplicate_and_pr_issues added and passing
• Timeout/ConnectionError backoff tests added and passing
• empty_env fixture fixed with yield statement
• All tests pass on Python 3.11+
• Test coverage increased from 9 → 16+ tests

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Related

• PR Add pytest test suite with mocked GitHub API responses #3: Add pytest test suite with mocked GitHub API responses