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docs/library-decisions/2026-05-14-@testing-library/jest-dom.md

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+---
+package: "@testing-library/jest-dom"
+version: "^6.5.0"
+tier: core
+decision: approved
+date: 2026-05-14
+deciders: [Danijel Martinek]
+adr: null
+filter-results:
+  license: MIT
+  types: native
+  maintenance: active
+  boundary-fit: pass
+  shadow-check: pass
+  eu-residency: n/a
+  cve-scan: clean
+  named-consumer: pass
+  socketRisk: clean
+verification-commands:
+  - npm view @testing-library/jest-dom license
+  - npm view @testing-library/jest-dom version
+  - pnpm audit --audit-level=moderate
+accepted-cves: []
+---
+
+## Filter: license
+
+<!-- Result: MIT -->
+
+`npm view @testing-library/jest-dom license` returns `MIT`. MIT is on the allowlist.
+
+## Filter: types
+
+<!-- Result: native -->
+
+`@testing-library/jest-dom` ships its own TypeScript declaration files that extend the vitest/jest `expect` matchers. No separate `@types/` package is needed.
+
+## Filter: maintenance
+
+<!-- Result: active -->
+
+Actively maintained by the Testing Library organization. The 6.x line is the current major. Regular releases tracking vitest and jest compatibility.
+
+## Filter: boundary-fit
+
+<!-- Result: pass -->
+
+`@testing-library/jest-dom` is a dependency of `@repo/core-testing`, which is the workspace's shared testing infrastructure package. Custom DOM matchers (`toBeInTheDocument`, `toHaveTextContent`, etc.) are set up in `core-testing`'s setup file and available to all feature test suites via the `core-testing` dependency. This is the correct placement.
+
+## Filter: shadow-check
+
+<!-- Result: pass -->
+
+`@testing-library/jest-dom` is the sole custom DOM matcher extension in the workspace. No competing matcher library is present.
+
+## Filter: eu-residency
+
+<!-- Result: n/a -->
+
+`@testing-library/jest-dom` is a test utility library with no network communication. EU residency does not apply.
+
+## Filter: cve-scan
+
+<!-- Result: clean -->
+
+`pnpm audit --audit-level=moderate` reports no advisories against `@testing-library/jest-dom` at the time of this trace.
+
+## Filter: named-consumer
+
+<!-- Result: pass -->
+
+`@repo/core-testing` uses `@testing-library/jest-dom` to set up custom DOM assertion matchers. Feature packages that render React components in tests use these matchers via `core-testing`. Named, non-hypothetical consumer exists today.
+
+## Prompt: replaces
+
+`@testing-library/jest-dom` extends vitest's `expect` with semantic DOM matchers, replacing brittle assertion patterns like `expect(el.innerHTML).toContain('text')` with `expect(el).toHaveTextContent('text')`.
+
+## Prompt: migration-cost-out
+
+Low. `@testing-library/jest-dom` is configured in one setup file in `@repo/core-testing`. Removing it requires updating that setup and replacing any DOM-specific matchers in test files with lower-level assertions.
+
+## Prompt: alternatives-considered
+
+1. **Plain vitest `expect` matchers only** — Viable but produces less readable test assertions for DOM state; `toBeInTheDocument()` is significantly clearer than checking element existence manually.
+2. **`@vitest/ui` accessibility assertions** — Narrower scope; `@testing-library/jest-dom` covers the full semantic DOM assertion surface.