[tela]

Motivation

The demo should show the mechanism behind "LocalStack for SaaS Applications": the app's code is the same whether it calls an app emulator or the real vendor, and only the base URL changes. Nobody should connect production credentials to a demo, so nothing is ever sent to a vendor. Production Mode shows the mechanism without breaking the demo.

Changes

• shared/wire: add Switch, which holds the base URL each vendor has been pointed at, and a proxy that asks it for the target on every call. A vendor pointed at its own service's URL is still answered by the app emulator, and the recorded call carries would_send_to, the URL it would have gone to. An empty or malformed URL is reported in the state and fails the call that uses it with a message that says what to do.
• shared/seed: show the proxy's reason as the error, instead of raw JSON.
• The lender's vendor calls follow the switch with no restart. GET /api/targets and PUT /api/targets read and change it. Reset and readiness only ever use the app emulators.
• UI: a non-dismissable banner for Demo Mode and Production Mode, where Production Mode is a warning. A gear overlay with a base URL field per vendor and Use emulator and Use service buttons. The page title is also the demo menu (one demo for now). The demo and the inspector share one header, title block included, with Demo and Demo Inspector as tabs doing the wayfinding, and the demo's progress lives above the router, so switching views keeps it. An arrow beside the tabs still opens the inspector in a second browser tab. The inspector tags each call that a dry run would have sent elsewhere. Apply stays disabled, with the reason, while a URL cannot be used.
• web/packages/brand: add --ls-warning (amber) and a warning badge variant. The style guide has no warning color, so it is an addition like --ls-danger, documented in the brand README, which also drops the stale "SaaS Apps" wording. The overlay backdrop uses the palette's navy, not black.
• Docs: apps/acme-commerce-lenders/docs/usage.md explains the modes.

There is no way to send a call to a vendor's service. An earlier version had a Live run style, which was removed in 2420493 because it needed credentials the demo does not have and made the demo look broken.

Tests

make vet                                                                                     # clean
make test                                                                                    # 15 packages ok, including new wire, seed, lender and api tests
pnpm --dir web lint                                                                          # clean
pnpm --dir web --filter @localstack-app-emulators/acme-commerce-lenders exec tsc --noEmit    # clean
pnpm --dir web --filter @localstack-app-emulators/acme-commerce-lenders test                 # 9 files, 45 tests passed
make check-kits check-samples                                                                # ok

Driven against the running demo (LocalStack Stripe, local Plaid and Xero): with Stripe and Xero pointed at https://api.stripe.com and https://api.xero.com, the whole flow ran from apply to settled. 14 of the 18 calls to read and connect carried would_send_to, only for Stripe and Xero. Pointing both back at the emulators returned to Demo Mode.

Related

Follows localstack-samples/localstack-app-emulators#17.