fix(ffe): make exposure event test deterministic

[sameerank]

Motivation

The FFE exposure-generation test intermittently timed out waiting for an exposure. It reused the generic test-flag key also used by other FFE coverage and did not verify that the request evaluated the configured variation, making failures ambiguous and susceptible to cross-test state.

Changes

• Give this test a dedicated flag key to avoid collisions with other FFE tests.
• Verify the feature flag evaluated to the configured on variation before checking its exposure.
• Keep all failure-producing assertions and waits in the test body so manifest xfails remain effective.
• Add return type annotations to the modified setup and test methods.

Validation

• ./run.sh FEATURE_FLAGGING_AND_EXPERIMENTATION tests/ffe/test_exposures.py::Test_FFE_Exposure_Events::test_ffe_exposure_event_generation (passed twice with the locally configured weblog)
• Mypy passed (529 source files)
• Ruff format and lint passed
• git diff --check passed

./format.sh proceeded through the Python, YAML, and parser checks, then encountered an unrelated macOS Bash 3 set -u failure in utils/scripts/shellcheck.sh when expanding an empty $@.

[github-actions]

CODEOWNERS have been resolved as:

tests/ffe/test_exposures.py                                             @DataDog/feature-flagging-and-experimentation-sdk @DataDog/system-tests-core

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7c845b7d20

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

[chatgpt-codex-connector]

Keep exposure assertions out of setup

When this file is xfailed by a manifest for unsupported tracer versions (for example the file-level version gates in manifests/dotnet.yml, manifests/golang.yml, and manifests/python.yml), this assertion now runs inside the repository's custom setup loop in pytest_collection_finish before pytest executes the xfailed test. A timeout here is re-raised as a setup/collection failure instead of being reported as an expected test failure, so running those declared-unsupported versions can abort the scenario. Keep the wait/assertion in the test body, or make the setup path avoid failing for xfailed items.

Useful? React with 👍 / 👎.

[datadog-prod-us1-6]

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: aa82f0d | Docs | Datadog PR Page | Give us feedback!}