testing-patterns_skill

Overview

This skill provides concrete testing patterns for writing and debugging unit tests, integration tests, and mocks across Effect-TS services, Svelte 5 stores, and Holochain zomes. It collects practical examples, helper conventions, and common pitfalls to speed up reliable test development. Use it to standardize test structure and avoid subtle mismatches between Promise vs Effect interfaces.

How this skill works

The skill documents distinct patterns for three layers: service tests (mock Holochain client with Promise-based callZome), store tests (mock services that return Effect values), and Tryorama integration scenarios (multi-agent zome calls with explicit DHT sync and record decoding). It explains how to create test runners, provide dependency layers, and encode record entries for zome payloads. It also lists module-level mocking rules and hREA-specific module mocks required for successful test runs.

When to use it

• Unit testing Effect-TS services that call zomes via a Holochain client
• Testing Svelte 5 stores that expect Effect-returning service implementations
• Setting up Tryorama multi-agent integration tests with DHT synchronization
• Mocking zome records where entry bytes must be msgpack-encoded
• Debugging failures caused by using Promises where Effects are required

Best practices

• Mock Holochain client methods with Promise-returning functions (mockResolvedValue / mockRejectedValue) for service tests
• Mock store dependencies to return Effect values (E.succeed / E.fail) when the store expects Effects
• Encode zome record entries using @msgpack/msgpack encode() for all mock records
• Perform module-level vi.mock() calls before importing stores that import other stores at module scope
• In Tryorama scenarios always call dhtSync() between agent operations and decode results with decodeRecord(s)

Example use cases

• Unit test a service create method by providing a mock Holochain client and asserting returned record from callZome
• Unit test a Svelte store by injecting a mock service that returns E.succeed(mockRecord) and verifying store state
• Run an integration test with two agents: get cells, call zomes, dhtSync between steps, and decode records
• Create mock records for assertions by encoding entry payloads with @msgpack/msgpack in test helpers
• Stub hREA and Apollo schema modules when running tests that depend on those libraries