Stabilize plugin MCP tools test#19191
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etraut-openai merged 2 commits intomainfrom Apr 23, 2026
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Summary
The plugin MCP tool-listing test could hide MCP startup failures by polling
ListMcpToolsuntil its own 30s deadline. If the plugin MCP server startup had already failed or timed out, the session-owned MCP manager would keep returning an empty tool list, so CI only reporteddiscovered tools: []instead of the startup state that mattered.This makes the test synchronize on
McpStartupCompletefor the sample plugin MCP server before asserting listed tools, and gives the Bazel-launched test server a larger startup window.Notes
Confidence is about 80%. The source path strongly supports the RCA: a failed MCP startup is represented as an empty tool list through
ListMcpTools, so the old polling contract could not distinguish "not ready yet" from "startup already failed." I could not retrieve the CI execution-log artifact to confirm the exact hidden startup error, but the observed Ubuntu Bazel failure matches this path: repeatedListMcpToolsresponses with no tools until the test-local timeout fired.I think this is the right solution because it keeps plugin behavior unchanged and fixes only the test contract. Future startup failures should now report the
McpStartupCompletefailure/cancellation instead of timing out on an empty tool snapshot.This test was introduced in #12864.