Provides concrete code-level fixes for each of the eight recurring flake patterns in flake-pattern-reference: replacing fixed sleeps with framework auto-waits, isolating state in beforeEach fixtures, stable role-based locators, mocking network + clock, seeding RNG, closing leaked resources, and the per-worker DB-schema fix for shared parallel state. Use when a flake is already classified by pattern and you need the specific code change to apply; to classify the pattern first use flake-pattern-reference or flake-axis-bisection, and to quarantine the test while the fix is in review use flaky-test-quarantine.

Wraps GrowthBook Node SDK testing patterns: GrowthBookClient initialization with direct payload (initSync; no network), isOn / getFeatureValue / evalFeature, scoped instances (createScopedInstance) for per-request user context, inline experiment (runInlineExperiment) tests, and tracking-callback assertion patterns. Use when writing tests for code using GrowthBook for flags + experiments.

Wraps VWO (Visual Website Optimizer) SDK testing patterns: SDK initialization with the settings file (offline-capable), `getFeatureVariableValue` and `activate` API, force-bucketing for per-test assignment, and assignment-integrity tests against the bucketing algorithm. Use when writing tests for VWO-instrumented application code.

Wraps Amplitude Experiment SDK testing patterns: client initialization with API key (or a bootstrapped local flag config for offline tests), the fetch / variant API, exposure-event suppression in tests, and assignment-integrity tests. Use when writing tests for code that uses Amplitude Experiment for A/B testing or flag management.

Author and run GoogleTest 1.17+ for embedded C++ on ARM targets - TEST() / TEST_F() / TEST_P() / TYPED_TEST(), EXPECT_* vs ASSERT_* assertions, fixtures with SetUp() / TearDown(), value-parameterised tests, GoogleMock when paired, cross-compile with arm-none-eabi-g++, run on host or under QEMU via the qemu-system-test-runner skill, --gtest_filter / --gtest_output=xml:results.xml / --gtest_shuffle / --gtest_repeat command-line flags, and XML / JSON output parsing for CI. Use when the unit-under-test is C++ (modern C++17+) and the team wants the de-facto C++ test framework instead of the C-only Unity. For C use unity-test-framework-c; for pure C mocks see the CMock reference in ceedling-build-runner.

Author and run Linear bug workflows via the GraphQL API: issue creation, state transitions (workflowState assignment), priority assignment (0 No priority / 1 Urgent / 2 High / 3 Medium / 4 Low), label-based classification, search by team and content. Covers the issueCreate mutation, issueUpdate for state transitions, the workflowStates query for per-team state IDs, and Linear's API-key vs OAuth Bearer auth modes; resolve-by-type, CI wiring, and result parsing live in references/. Use when the target tracker is Linear specifically; for other trackers use jira-bug-workflow-runner (Jira) or github-issues-bug-workflow (GitHub Issues). Files and transitions the issue; reproducing the defect is a separate concern.

Pure-reference catalog of defect categorisation taxonomies. Covers the IEEE 1044-2009 anomaly classification (anomaly class, anomaly type, anomaly severity, root cause category), the ISTQB CTAL-TA root-cause taxonomy (requirements / design / implementation / interface / test-data / build-environment), and the Orthogonal Defect Classification (ODC) eight-attribute framework. Maps each taxonomy to a worked example showing how the same defect classifies under each. Use to categorise defects consistently across a team, drive root-cause analysis, and inform process-improvement decisions (where in the SDLC do we leak the most defects?).

Authors and runs dbt data tests (generic, singular, and custom-macro), parses test failure output from run_results.json, and gates dbt build on test results. Use when the user works with a dbt project, asks about model assertions, or needs CI gates on a data pipeline.

Wraps `buf breaking` to compare a Protobuf schema against a past version, classifies breaking changes by category (FILE / PACKAGE / WIRE_JSON / WIRE), configures buf.yaml rule selection plus per-path exemptions, and gates CI on the exit code. Use when reviewing `.proto` changes in a PR for gRPC services, BSR modules, or schema-versioned message bus payloads.

Configures a CI matrix that runs tests across operating systems (Linux / macOS / Windows) and runtime versions (Node 18/20/22; Python 3.10/3.11/3.12; Java 17/21; .NET 6/8). Wires GitHub Actions matrix syntax, addresses OS-specific quirks (path separators, line endings, file permissions). Use when the product ships across OS / runtime combinations and the team needs continuous cross-platform coverage.

Authors tests against Okta - uses org-isolation strategy (per-PR org via Okta Developer Edition vs shared org with namespaced data); tests sign-in policy + MFA enforcement; exercises Okta Identity Engine (OIE) workflows including factor enrollment, recovery flows, and SCIM provisioning; tests scoped API tokens for least-privilege automation. Use when the user works with Okta as IdP and needs unit / integration tests for org config, sign-in policies, or OIE workflows.

Tests AWS SQS queue interactions - Standard (at-least-once delivery, near-unlimited throughput) vs FIFO (exactly-once processing, ordered) queue semantics; visibility-timeout interaction model; dead-letter queue (DLQ) for poison-message isolation; message retention period (default 4 days, configurable 60s - 1209600s); test patterns via LocalStack or `aws-sdk-client-mock` (TypeScript) / `moto` (Python). Use when the user works with AWS SQS producers/consumers and needs unit/integration tests for queue interactions.

Authors and runs Sidekiq job tests in Ruby - three Sidekiq::Testing modes (`fake!` jobs accumulate in arrays, `inline!` runs jobs immediately, `disable!` enqueues to Redis as normal); RSpec + Minitest helper patterns; clears jobs between tests via `Sidekiq::Worker.clear_all`; assertion patterns on `MyWorker.jobs.size` and `MyWorker.jobs.first[:args]`. Use when the user works with Sidekiq workers and needs unit / integration tests for job enqueueing, scheduling, retry behavior, or unique-job semantics.

Authors Karate `.feature` files using its Gherkin-flavored DSL for HTTP API tests, leverages the `match` keyword with fuzzy validators (#number / #string / #regex / contains / arrays), runs the suite via JUnit 5 plus Maven Surefire, and produces JUnit XML for CI gating. Use when the project is on the JVM and prefers a feature-file authoring flow over Java-DSL fluent chains; for those fluent chains use restassured-testing, for the same YAML-style flow on a Python/pytest stack use tavern-testing.

Author and run E2E tests on Sauce Labs - cloud grid for cross-browser + real-device testing with W3C WebDriver, Cypress, Playwright, and Appium support. Covers SAUCE_USERNAME + SAUCE_ACCESS_KEY auth, regional hub URLs (us-west-1 / us-east-4 / eu-central-1), W3C capabilities, sauce:options dict (build, name, screenResolution, tunnelName), Sauce Connect Proxy for internal-environment testing. Use for cross-browser regression with Sauce Labs as the cloud grid; complements BrowserStack + LambdaTest as alternative providers.