test: add tests and test tooling for MCP-UI

[tsck]

Proposed changes

• Adds unit and integration tests for the MCP-UI response augmentation
• Adds testing-library tooling for DOM testing

[coveralls]

Pull Request Test Coverage Report for Build 20309906400

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.5%) to 79.886%

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Totals
Change from base Build 20309766857:	0.5%
Covered Lines:	6777
Relevant Lines:	8403

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💛 - Coveralls

[Copilot]

Pull request overview

This PR adds comprehensive testing infrastructure and test coverage for the MCP-UI response augmentation feature. The changes introduce DOM testing capabilities using React Testing Library and happy-dom, along with unit and integration tests to verify UI component behavior and the MCP-UI feature implementation.

Key changes:

• Testing infrastructure setup with happy-dom environment and React Testing Library
• Unit tests for UIRegistry, useRenderData hook, and ListDatabases component
• Integration tests verifying MCP-UI feature behavior with and without the feature flag

Reviewed changes

Copilot reviewed 11 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
vitest.config.ts	Adds new test configuration for UI components with happy-dom environment
vite.ui.config.ts	Changes generated tool module extension from .ts to .js for compatibility
tsconfig.test.json	New TypeScript config for test files with isolated modules support
tests/unit/ui/registry/registry.test.ts	Unit tests for UIRegistry functionality
tests/unit/ui/hooks/useRenderData.test.tsx	Unit tests for useRenderData React hook
tests/unit/ui/components/ListDatabases/ListDatabases.test.tsx	Unit tests for ListDatabases component
tests/unit/toolBase.test.ts	Extended tests for ToolBase UIResource functionality
tests/setupReact.ts	Setup file importing jest-dom matchers for vitest
tests/integration/ui/mcpUIFeature.test.ts	Integration tests for MCP-UI feature
package.json	Adds testing-library dependencies and moves React to devDependencies
eslint.config.js	Updates test file patterns to include .tsx files

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported