Testing & Quality skills

Browse reusable Agent Skills, each with a clear purpose and practical guidance.

cloudsql-idle-connection-timeout

Fix psycopg2 "could not receive data from server: Operation timed out" or "connection already closed" errors when using Cloud SQL with long-running Python scripts. Use when: (1) psycopg2.OperationalError after a period of no DB activity, (2) DB connection works initially but fails after a non-DB phase (API calls, file processing, CDX scans), (3) Cloud SQL managed PostgreSQL kills idle connections. The fix is to defer DB connection opening until needed, or add reconnection logic for long-running batch processes.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

curl-head-vs-get-header-debugging

Fix misleading HTTP response header values when debugging with curl -I or curl -sI. Use when: (1) Response headers differ between curl testing and actual browser/client behavior, (2) Cache-Control or other headers show unexpected values despite correct middleware code, (3) Server-side middleware that only applies to GET requests appears to not work when testing with curl -I. The -I flag sends HEAD requests, and middleware that checks for GET method will skip processing, returning handler-level headers instead of middleware-overridden ones.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

dart-lifecycle-disposed-flag-overload

Fix Dart/Flutter services where calling start() after stop() is a silent no-op because stop() sets a _disposed (or similar) flag that start()'s guard short-circuits on. Use when: (1) A repository/service/controller has startListening/stopListening, subscribe/unsubscribe, open/close, or similar lifecycle methods, (2) Re-opening the service after closing it appears to do nothing — no subscription, no events, no error, (3) Unit tests that only exercise a single mount/open/start cycle pass while the real app breaks on the second visit to a screen, (4) A boolean flag is used both for "in the middle of tearing down this instance forever" AND for "currently stopped, can be re-started". Common in Riverpod/Bloc-driven screens that wire startListening() in initState and stopListening() in dispose — the second time the user visits the screen, nothing happens.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

debug-algorithm

Diagnoses QuantConnect Python (.py) and C# (.cs) algorithm failures: runtime exceptions and zero-trade backtests. Invoked by other agents the moment an algorithm throws a runtime error or completes a backtest with 0 orders. Walks an ordered checklist to the root cause without hiding it. Trigger phrases: "runtime error", "stack trace", "0 orders", "no trades", "flat equity curve", "unknown property", "AttributeError", "KeyNotFoundException", "wasn't found in the DataDictionary", "insufficient buying power", "indicator not ready", "debug the algorithm".

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

debug-performance

Diagnoses slow QuantConnect Python (.py) and C# (.cs) backtests using the Performance Chart first and Python cProfile only when the chart does not pinpoint the hot function. Trigger phrases: "slow backtest", "high CPU", "algorithm slow", "CPU usage", "RAM usage", "memory usage", "performance chart", "profiling", "bottleneck", "debug performance", "taking too long", "optimize algorithm".

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

equatable-linkedhashmap-lru-reorder

Fix LRU-bounded Flutter/bloc state classes that silently lose insertion-order updates. Use when: (1) a state class uses `Equatable` with a `LinkedHashMap<K, V>` field to preserve insertion order (LRU, MRU, recent-items caches), (2) `Cubit.emit` appears to drop emissions when an existing key is re-inserted or moved to most-recent, (3) LRU eviction evicts the "wrong" entry after a refresh, (4) a test that reports the same key twice and then overflows the cap sees the refreshed entry evicted instead of the oldest. Root cause: Equatable's default map comparison is structural (unordered), so reordering without changing keys/values produces an "equal" state that `Cubit.emit` suppresses.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

fastly-compute-native-test-linker-failure

Fix Fastly Compute Rust crate `cargo test` failures with "ld: symbol(s) not found" errors for Fastly SDK symbols like `_version_set`, `_body_new`, `_req_send` on native host builds. Use when: (1) `cargo test` on a Fastly Compute crate fails at link time with errors mentioning libfastly and symbols with names like `fastly::http::response::handle::...`, (2) You added a `#[cfg(test)]` module to a file in a Fastly Compute binary crate and the tests never seem to run or fail to link, (3) Existing `#[cfg(test)]` modules in src/main.rs or its sibling modules appear dead despite being present in the source tree, (4) `cargo test --lib` works but `cargo test` fails.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

fastly-kv-concurrent-write-retry

Fix intermittent 500 errors with "Failed to store" in Fastly KV Store during concurrent writes. Use when: (1) Batch operations fail with ~10-20% error rate, (2) Error contains "Failed to store list" or similar KV write failures, (3) Multiple requests updating the same KV key simultaneously, (4) Read-modify-write pattern without locking. The fix is adding a retry loop that re-reads before each write attempt.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

fastly-multi-service-routing-debug

Debug Fastly Compute services where code changes don't affect behavior due to multi-service routing architecture. Use when: (1) deployed changes have no effect, (2) unexpected redirects persist after code updates, (3) DNS resolves to Fastly but responses don't match deployed code, (4) `fastly service list` shows multiple related services. The root cause is often a routing/gateway service intercepting requests before they reach your content service.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub

ffmpeg-kit-macos-codesign-crash

Fix Flutter macOS app crash at launch due to FFmpeg Kit library loading failure. Use when: (1) macOS app builds successfully but crashes immediately on launch, (2) Crash log shows "Library not loaded: libfontconfig.1.dylib" or similar homebrew library, (3) Error mentions "code signature not valid for use in process" with "different Team IDs", (4) Using ffmpeg_kit_flutter_new (Full GPL variant). The Full GPL variant has external dependencies on homebrew libraries that fail macOS code signing. Switch to ffmpeg_kit_flutter_new_min.

257 repo starsObserved in 1 repos

Testing & Quality

GitHub