Context Testing

Problem

Components that rely on context break when tested in isolation because the required context providers aren’t available. Tests pass with mocked context values that don’t match production, hiding bugs where components misuse or incorrectly consume context data.

Solution

Test components that consume context by wrapping them in test providers with controlled values. This verifies components behave correctly with different context states without needing full application setup.

Example

This example demonstrates how to test a component that consumes context by wrapping it in a test provider with controlled values.

test('displays user name from context', () => {
  // Render component wrapped in context provider with test data
  const { getByText } = render(
    <UserContext.Provider value={{ name: 'Alice' }}>
      <UserProfile />
    </UserContext.Provider>
  );

  // Verify component correctly displays the context value
  expect(getByText('Alice')).toBeInTheDocument();
});

Benefits

• Verifies components correctly consume and respond to context values.
• Enables testing different context states without full application setup.
• Catches bugs where components misuse or incorrectly access context.
• Simpler than integration tests while still validating context behavior.
• Makes it easy to test edge cases with unusual context values.

Tradeoffs

• Requires creating test provider wrappers which adds boilerplate.
• May not catch issues with actual provider implementation.
• Can give false confidence if test context differs from production.
• Nested context providers in tests can become complex to set up.
• May need to update tests when context shape changes.