Fake Provider Harness + E2E Gate

Sindri the Assayer — QA Engineer

In one breath

A local Miniflare harness serves deterministic fake banks and a signed fake plugin catalog so the full provider-plugin trust chain can be exercised in CI without touching a real bank or a Mac.

By the end of this chapter you’ll understand:

• How the fake-provider harness simulates a Cloudflare distribution endpoint locally
• Why deterministic test fixtures matter for plugin trust and distribution flow coverage
• How this gate fits into the broader CAS-3499 provider-plugin CI pipeline

Fake Provider Harness + E2E Gate

Status: Delivered
CAS: CAS-3605
Delivered: 2026-05-18
PR: #968

What changed

A local-only Miniflare fake-provider harness was added for deterministic provider-plugin end-to-end tests. It runs with wrangler dev --local on port 8791, serves stable fake bank responses and a signed fake plugin catalog, and is not deployed to any Cloudflare subdomain.

Why it matters

• Gives repeatable safety checks for provider-plugin behavior.
• Reduces regression risk on plugin distribution/trust flow.
• Keeps iOS/Desktop behavior aligned by verifying the same plugin protocol end-to-end.

Technical anchors

• workers/fake-providers/
• playwright.fake-providers.config.ts
• docs/features/CAS-3499-declarative-cf-provider-plugins.md

See it as

A flight simulator for the plugin distribution runway: the plane (app) goes through every preflight check — fuel (trust verification), instruments (schema validation), clearance (catalog fetch) — against a fully controlled ground environment, so no live traffic is ever at risk during testing.

Recap

• The harness runs wrangler dev --local on port 8791 and is never deployed to any Cloudflare subdomain, keeping test and production environments strictly separate.
• Deterministic fake bank responses and a signed fake catalog let 14 Playwright scenarios cover the complete trust→download→verify→scrape chain repeatably.
• This gate is the safety net for regression risk on the plugin distribution and trust flow introduced in CAS-3499.

What changed {#what-changed}

See: CHANGELOG → 2026-05-18