#10271 7373b4c Thanks @jacoblee93! - feat(core): Use uuid7 instead of v4 for generating run ids
#10262 b0175a5 Thanks @maahir30! - fix: Move fakeModel from utils/testing to testing namespace
move to updated namespace
#10185 414f6ed Thanks @maahir30! - feat: add custom Vitest matchers for LangChain message and tool call assertions
Adds a new @langchain/core/testing/matchers export containing custom Vitest matchers (toBeHumanMessage, toBeAIMessage, toBeSystemMessage, toBeToolMessage, toHaveToolCalls, toHaveToolCallCount, toContainToolCall, toHaveToolMessages, toHaveBeenInterrupted, toHaveStructuredResponse) that external users can register via expect.extend(langchainMatchers) in their Vitest setup files. Re-exported from langchain for convenience.
Fetched April 7, 2026