fix: use isinstance() fallback for exception subclass matching in HttpStatusErrorHandler

[devin-ai-integration]

Summary

HttpStatusErrorHandler.interpret_response() used exact class matching (dict.get(exception.__class__)) to look up exception types in the error mapping. The DEFAULT_ERROR_MAPPING maps RequestException to transient_error, but when a subclass like ConnectionError or ChunkedEncodingError was encountered, dict.get(ConnectionError) returned None because it is not the same class as RequestException.

This caused transient network errors to fall through to the else branch, producing the misleading message "Unexpected exception in error handler" and classifying them as system_error instead of transient_error.

Fix: After the exact dict.get() lookup fails, iterate through the mapping's exception-type keys and use isinstance() to find a match. Exact class match still takes precedence for performance and specificity.

Resolves https://github.com/airbytehq/oncall/issues/12124:

• https://github.com/airbytehq/oncall/issues/12124

Declarative-First Evaluation

Not applicable — this is a CDK-level fix in the imperative HTTP error handler infrastructure, not a connector-level change.

Test Coverage

Added 7 new test cases covering the fix:

• Parametrized subclass tests (ConnectionError, ChunkedEncodingError, ReadTimeout, ConnectTimeout) — all resolve to transient_error via the RequestException mapping
• Custom exception mapping test — verifies isinstance fallback works with user-provided mappings
• Precedence test — verifies exact class match takes priority over isinstance fallback
• Existing tests for RequestException (exact match), Exception (unmapped), and other paths continue to pass

Breaking Change Evaluation

Not a breaking change. The fix only adds a fallback lookup path — existing exact-match behavior is preserved. No public API, schema, spec, or state format changes.

Review & Testing Checklist for Human

• Verify the isinstance() fallback iteration order is acceptable (it uses dict insertion order, matching the first parent class found)
• Confirm that the issubclass(mapped_key, Exception) guard is sufficient to skip non-exception keys (int status codes) during iteration

Notes

• The CDK uses semantic-pr-release-drafter for versioning, so no manual version bump is needed.
• This fix benefits all connectors using HttpStatusErrorHandler (or the default error handler) without requiring any connector-level changes.

Link to Devin session: https://app.devin.ai/sessions/4550ef11ab60443096c77cfe3fc6854f

[devin-ai-integration]

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PyTest Results (Fast)

4 046 tests  +6   4 035 ✅ +6   7m 56s ⏱️ +11s
    1 suites ±0      11 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit ff9ab21. ± Comparison against base commit 886fcf8.

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PyTest Results (Full)

4 049 tests  +6   4 037 ✅ +6   10m 59s ⏱️ -24s
    1 suites ±0      12 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit ff9ab21. ± Comparison against base commit 886fcf8.