eigen-testing

name	eigen-testing
description	Write and maintain tests for Eigen, a React Native application using React Native Testing Library and Relay Test Utils. Use this skill when writing new tests, fixing failing tests, adding test coverage, updating existing tests, or when asked about testing best practices for Eigen. Triggers on requests like "write tests for this component", "add test coverage", "fix this test", "how should I test this", or any testing-related questions for the Eigen codebase. Use when this capability is needed.
metadata	{"author":"artsy"}

Eigen Testing Skill

Use this skill to write high-quality tests for Eigen following established patterns and best practices.

Quick Start

For Non-Relay Components

Use the template at assets/component-test-template.tsx as a starting point:

import { fireEvent, screen } from "@testing-library/react-native"
import { renderWithWrappers } from "app/utils/tests/renderWithWrappers"

For Relay Components

Use the template at assets/relay-test-template.tsx as a starting point:

import { setupTestWrapper } from "app/utils/tests/setupTestWrapper"
import { graphql } from "react-relay"

Critical Rules

1. File Location: Always place tests in __tests__ directories colocated with source files
2. File Naming: Use .tests.tsx (not .test.tsx or .spec.tsx)
3. Never Use Deprecated Utilities: Avoid renderWithWrappersLEGACY, setupTestWrapper_LEGACY, resolveMostRecentRelayOperation, flushPromiseQueue, waitUntil, extractText, renderWithLayout
4. Analytics Testing: Always use toMatchInlineSnapshot() pattern for tracking events
5. Async Operations: Use findBy* queries, not waitUntil or promise flushing

Test Structure Pattern

Follow Arrange-Act-Assert:

describe("ComponentName", () => {
  it("does something specific", () => {
    // Arrange: Set up and render
    renderWithWrappers(<Component />)

    // Act: Trigger behavior
    fireEvent.press(screen.getByTestId("button-id"))

    // Assert: Verify outcome
    expect(mockNavigate).toHaveBeenCalledWith("/path")
  })
})

Common Patterns

Testing Navigation

import { navigate } from "app/system/navigation/navigate"

expect(navigate).toHaveBeenCalledWith("/artwork/artwork-slug")

Testing Analytics

import { mockTrackEvent } from "app/utils/tests/globallyMockedStuff"

expect(mockTrackEvent).toHaveBeenCalledTimes(1)
expect(mockTrackEvent.mock.calls[0]).toMatchInlineSnapshot()
// Run test to generate snapshot, then verify it's correct

Testing Relay Data

renderWithRelay({
  Me: () => ({
    name: "John Doe",
    artworks: {
      edges: mockEdges(10), // Use mockEdges for paginated data
    },
  }),
})

Testing Error States

const { mockRejectLastOperation } = renderWithRelay()
mockRejectLastOperation(new Error("Network error"))

Detailed Guidelines

For comprehensive testing patterns, utilities, and examples, refer to:

• references/testing-guidelines.md - Complete testing documentation

Read this file when you need:

• Detailed examples of testing patterns
• Information about wrapper props and configuration
• Guidance on what to test and what not to test
• Mock helpers and utilities
• Additional resources and links

TestID Conventions

Use descriptive, kebab-case test IDs:

• artwork-save-button
• artist-series-list-item
• price-display-container

Running Tests

yarn test                                    # Run all tests
yarn test:watch                              # Watch mode
yarn test path/to/file.tests.tsx             # Test specific file

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Source: artsy/eigen — distributed by TomeVault.