chore: modernize repository

[JP-Ellis]

Modernises the entire frontend toolchain in one shot. The app is fully functional after this commit: npm run test:pact still passes, npm run build produces a clean Vite bundle.

The following main replacements have been performed:

• react-scripts (CRA) — replaced by Vite
• prop-types — replaced by TypeScript
• cross-env, dotenv — no longer needed with Vite's env handling
• @babel/preset-react — superseded by @vitejs/plugin-react
• eslintConfig field and browserslist field from package.json
• .eslintrc.json — replaced by Biome

All remaining dependencies should be up to date.

All 10 source files converted from .js/.jsx to .ts/.tsx:

• product.ts — adds ProductData interface; Product class typed

• api.ts — full method signatures; REACT_APP_API_BASE_URL → import.meta.env.VITE_API_BASE_URL; substr → slice

• App.tsx — class component → functional with useState/useEffect/ useMemo; PropTypes removed; <Link to={state: ...}> fixed for RR v7

• ProductPage.tsx — class → functional; window.location.pathname → useParams<{ id: string }>()

• ErrorBoundary.tsx — kept as class component (required by React's error boundary API); typed with ErrorBoundaryProps/ErrorBoundaryState

• Heading.tsx, Layout.tsx — typed functional components; PropTypes removed

• index.tsx — removes invalid history="" prop from <BrowserRouter>

• api.pact.spec.ts — adds // @vitest-environment node docblock so pact tests run against a real Node HTTP server rather than jsdom

• setupTests.ts — rename only

• tsconfig.json — strict mode, moduleResolution: bundler, noEmit, jsx: react-jsx; types include vitest/globals, @testing-library/jest-dom, node

• vite.config.ts — React plugin, port 3000, outDir: build, envPrefix: ["VITE_", "PACT_"]

• vitest.config.ts — jsdom environment, globals, 30 s timeout, setup file

• biome.jsonc — VCS gitignore integration (excludes build/, pacts/ automatically); noDefaultExport suppressed only for *.config.ts files where Vite/Vitest mandate it

• .editorconfig — UTF-8, LF, 2-space indent, final newline

• .env.example — documents VITE_API_BASE_URL

• index.html — root Vite entry point (replaces public/index.html)

• src/vite-env.d.ts — /// <reference types="vite/client" />

• package.json — "type": "module", "engines": {"node": ">=24.0.0"}; full script suite including dev, type-check, check, check:fix

• Makefile — REACT_APP_API_BASE_URL → VITE_API_BASE_URL in fake_ci

• .github/workflows/build.yml — npm i → npm ci; env var renamed; quality gates added before test step: type-check, check, build

• README.md — updated stack table, prerequisites, scripts table, env vars

Ref: PACT-6016

[Copilot]

Pull request overview

Modernizes the frontend build/test/lint toolchain by migrating from CRA + Babel + ESLint/PropTypes to Vite + Vitest + TypeScript + Biome, while converting the app codebase from .js/.jsx to .ts/.tsx and updating routing/tests accordingly.

Changes:

• Replace CRA (react-scripts) with Vite for dev/build and Vitest for testing.
• Migrate code to TypeScript and update React components to typed functional patterns (keeping class-based error boundary).
• Replace ESLint/Prettier-style configuration with Biome; update CI workflow/scripts/docs and environment variable naming for Vite.

Reviewed changes

Copilot reviewed 31 out of 33 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
vite.config.ts	Introduces Vite config (plugins/server/build/envPrefix) for the new toolchain.
vitest.config.ts	Adds Vitest configuration for jsdom tests + setup files and includes patterns.
tsconfig.json	Adds strict TypeScript compiler configuration for the migrated source.
package.json	Switches scripts/deps to Vite/Vitest/TS/Biome; adds ESM + Node engine requirement.
index.html	Adds Vite entry HTML as the new app root template.
src/vite-env.d.ts	Adds Vite client type references for import.meta.env.
src/setupTests.ts	Aligns test setup import style for the Vitest environment.
src/api.ts	Types the API layer and switches env handling to import.meta.env.
src/api.pact.spec.ts	Updates Pact test for Vitest + node environment and TypeScript.
src/product.ts / src/product.js	Converts Product model to TypeScript with an explicit data interface.
src/App.tsx / src/App.js	Converts App to typed functional component with hooks + updated links.
src/ProductPage.tsx / src/ProductPage.js	Converts product page to hooks + router params.
src/index.tsx / src/index.js	Updates entrypoint for Vite + router setup and safer root mounting.
src/Layout.tsx / src/Layout.js	Converts Layout to typed component and removes PropTypes.
src/Heading.tsx / src/Heading.js	Converts Heading to typed component and removes PropTypes.
src/ErrorBoundary.tsx	Types the error boundary and removes PropTypes usage.
src/index.css	Formatting updates consistent with new formatter rules.
.github/workflows/build.yml	Updates CI to use npm ci and adds type-check/lint/build gates.
Makefile	Renames env var usage to VITE_API_BASE_URL for fake CI.
README.md	Updates documentation to reflect new toolchain, scripts, and env vars.
biome.jsonc	Adds Biome configuration and config-file overrides.
.editorconfig	Adds repository-wide editor defaults aligned with formatting choices.
.env.example	Documents VITE_API_BASE_URL for local configuration.
public/index.html	Removes CRA public HTML template (superseded by Vite root index.html).
.eslintrc.json	Removes legacy ESLint configuration (replaced by Biome).
.github/renovate.json	Minor formatting cleanup.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.