Add typed JSON output to Hydrogen setup commands

[gonzaloriestra]

WHY are these changes introduced?

Setup commands need structured receipts describing what was configured and whether the operation completed.

WHAT is this pull request doing?

Add schemas and --json to setup, setup css, setup markets and setup vite. Preserve terminal presentation and return configured, built-in or cancelled results as applicable. Wait for setup tasks before emitting the final result.

Without --json, the existing terminal presentation remains. Example JSON result:

shopify hydrogen setup css --json

{"status":"built-in","directory":"/project","strategy":"css-modules","files":[],"dependenciesInstalled":false,"needsNpmReinstall":false}

HOW to test your changes?

pnpm --filter @shopify/cli-hydrogen test src/commands/hydrogen/setup/json-output.test.ts

Build and typecheck were checked at each layer. The full stack passed 498 tests (6 skipped), lint, and schema discovery for all 22 finite commands. Command-line smoke checks covered a successful unlink result, fatal project errors, watch-mode rejection and schema environment flags. Live authenticated Shopify operations have not been exercised.

Stack

Draft 8 of 9. Previous: #4101. Next: #4103. One changeset is included in #4103.

1. Prepare Hydrogen commands for typed JSON output
2. Add typed JSON output to Hydrogen build tooling
3. Add typed JSON output to hydrogen customer-account-push
4. Add typed JSON output to hydrogen deploy
5. Add typed JSON output to Hydrogen environment commands
6. Add typed JSON output to Hydrogen route generation
7. Add typed JSON output to Hydrogen project and account commands
8. Add typed JSON output to Hydrogen setup commands
9. Add typed JSON output to Hydrogen maintenance commands

[shopify]

Oxygen deployed a preview of your gonzalo/hydrogen-json-setup branch. Details:

Storefront	Status	Preview link	Deployment details	Last update (UTC)
Skeleton (skeleton.hydrogen.shop)	✅ Successful (Logs)	Preview deployment	Inspect deployment	September 29, 2026 2:58 PM

Learn more about Hydrogen's GitHub integration.

[fredericoo]

small comments but overall this looks good. Human output is unchanged, the prompt behaviour matches the rest of the stack (prompts stay, same as env in #4099), and errors go through the shared path. The only real gap is that hydrogen setup itself has no behavioural JSON test.

nice catch on awaiting backgroundWorkPromise in the !i18n && !createShortcut early return, too. Before, IIRC, it returned without waiting on the copy/route work, so any failure there ended up as an unhandled rejection.

[fredericoo]

non-blocking: hydrogen setup is the most involved command in this PR, but its only test is this flag/schema check. Two things aren't covered: the early-return path, which now awaits background work and returns routes, and shortcut flipping to true once createShortcut() succeeds. It's also the one result carrying extra fields (cliCommand, showSummary) that rely on zod stripping them in encode.

Let's add one test that runs runSetup({directory, markets: 'none', shortcut: false, installDeps: false}) and asserts the exact stdout with toEqual. That way a leaked internal field or a missing routes would fail it.