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Browsers need not apply, UI testing with Lustre and Gleam

Talkat Code BEAM Europe 2025 · 2025-11-05..11-06· [testing, web-performance]
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Luster on Gleam separates model, update and view so tests hit the right thing: unit-test the update function for business logic, run view assertions and a query DSL for presentation, take textual snapshots with birdie for content diffs, and use a Storybook-like Fable + a browser only for design checks. A simulate module folds messages to emulate journeys and avoids spinning real browsers (no more half-hour CI times); Gleun runs tests, RSVP handles HTTP.

AI-written summary · about

  1. 0:00UI testing with Lustre and Gleam
  2. 1:07Hate traditional UI tests
  3. 3:38Four UI test categories
  4. 4:41React component limits
  5. 6:26Lustre/Gleam component separation
  6. 9:39Unit tests for business logic
  7. 11:05Presentation logic in Lustre
  8. 13:36User journeys without browsers
  9. 14:40Text snapshots for content
  10. 15:23Design tests with components
  11. 16:25Tailor test strategies
  12. 16:47Lustre’s testing ecosystem
  13. 17:10Q&A
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