effect-testing-patterns

Effect-TS Testing Patterns and Best Practices

Test Framework Setup

Use @effect/vitest for Effect-TS Tests

• Always use @effect/vitest for tests involving Effect-based code
• Import test functions from @effect/vitest, not regular vitest
• Use describe, expect, and it from @effect/vitest

import { describe, expect, it } from '@effect/vitest'
import { Effect as E, Exit } from 'effect'

Import Patterns - ALWAYS Use Relative Paths

• CRITICAL: Always use relative paths for internal imports, never src/ aliases
• Use relative paths like ../../stores/blog/blog.store.js
• Use package imports for external dependencies like @t6c/blog-domain
• Store files follow pattern: store-name.store.ts

// ✅ CORRECT - Relative paths for internal imports
import { BlogStore } from '../../stores/blog/blog.store.js'
import { SearchStore } from '../../stores/search/search.store.js'

// ✅ CORRECT - Package imports for external dependencies
import { BlogPost, mockBlogPost1 } from '@t6c/blog-domain'
import { Effect as E } from 'effect'

// ❌ WRONG - Never use src/ aliases in tests
import { BlogStore } from 'src/stores/blog/blog.store.js'

AI Service Testing Patterns

AiStore.generateObject Mocking

• Use AiStore.makeTestService to mock AI operations
• Create proper AiResponse.WithStructuredOutput responses
• Use generic type parameter <A>() for flexible type handling
• Include realistic mock data that matches your schema

import { AiResponse, AiStore } from '@t6c/lib-ai'

// ✅ CORRECT - Complete AI service mocking pattern
const testAiStore = AiStore.makeTestService({
  generateObject: <A>() =>
    E.succeed(
      new AiResponse.WithStructuredOutput({
        id: AiResponse.ToolCallId.make('1'),
        name: '1',
        parts: mockResponse.parts,
        value: CommentProcessingOutput.make({
          htmlContent: 'test',
          status: 'active',
          toxicityScore: 0,
          sentiment: 'positive',
          moderationReason: 'test',
          categories: [],
        }) as A,
      }),
    ),
})

// ❌ WRONG - Incomplete or incorrect AI mocking
const testAiStore = AiStore.makeTestService({
  generateObject: () => E.succeed({ htmlContent: 'test' }), // Missing proper structure
})