E2E expansion Phase A: new capabilities, artifacts, dispatch, and transports #25350

Priority

Highest. Add capabilities whose success depends on a live Actions runner, external state, persisted artifacts, event routing, or real network/tool startup. These are not adequately covered by compiler or unit tests.

Candidate tests

• Add e2e test: copilot/upload-artifact #16262 — upload-artifact: stage a deterministic file and verify the downloaded artifact contents.
• Suggested test: copilot/custom-safe-outputs-job-artifacts #17711 — custom safe-output job artifacts: verify artifacts cross the generated custom-job boundary.
• Suggested test: copilot/dispatch-workflow-work-queue #19912 — dispatch-workflow work queue: prove queued dispatches execute with the intended inputs and ref.
• Suggested test: copilot/dynamic-workflows-engine-support #20389 — dynamic workflow engine support: execute a dynamically selected engine end to end.
• Suggested test: copilot/checkout-multi-repository-explicit-opt-in #22852 — multi-repository checkout opt-in: validate both worktrees and live authorization.
• Suggested test: copilot/repository-dispatch-bots-allowlist #18154 — repository_dispatch bot allowlist: assert accepted and rejected activation identities.
• Suggested test: copilot/web-fetch-builtin-tool #17290 — built-in web-fetch: exercise a real allowlisted fetch through the hosted tool.
• Suggested test: copilot/web-search-builtin-tool #17710 — built-in web-search: validate tool registration and a real result path.
• Suggested test: copilot/mcp-http-custom-ca-trust #24900 — custom CA trust for HTTP MCP: connect to a controlled TLS fixture with the configured CA.
• Suggested test: copilot/mcp-startup-timeout-slow-server #23422 — slow MCP startup timeout: validate startup timing, timeout, and surfaced failure behavior.

Completion criteria

Each test must assert externally visible runtime behavior, not only compilation or lockfile contents. Prefer deterministic samples and reusable, cleanable fixtures.

Fresh reprioritization of all 50 open suggested new test issues on 2026-10-25. This supersedes the numbered phase trackers.