Fredrik Teschke

phoenix_test_playwright v0.12.0 released 🥳 Shorthand to eval JS in browser, assert_path fixes for LiveView navigations, and more. Also ships with usage-rules.md for LLM coding agents. 🤖 #elixirlang

Rewrote ultimate.ftes.de from JS to Elixir 🎸 Free tool to convert music chordsheets (UltimateGuitar → ChordPro, etc.). Ported ChordsheetJS to Elixir with Claude — surprisingly few manual interventions needed. Now on Phoenix and finally motivated to build new features!

Playwright remote server support (websocket) for phoenix_test_playwright 🥳 Looking for early feedback — especially around CI setups. "Remote server playbook" for the docs. Please give the main branch a spin: github.com/ftes/phoenix_t… Hat tip to Carson and Tyler! #elixirlang

phoenix_test_playwright 0.10.1 released 🥳 Small macro, big effect 🪄: step/3 groups trace actions and AUTOMATICALLY links to source code line Big thanks to @nathanl for adding this!

TIL Oban's unique job period uses fixed time windows, not sliding windows. A job with unique: [period: {7, :days}] can still allow duplicates 2 days apart if they fall into different buckets. For sliding windows use a custom query. ftes.de/articles/2026-… #elixirlang #oban

🎉 phoenix_test_playwright 0.10.0-rc.0 released Breaking changes - if you are reaching beyond the PhoenixTest API into internals. Upside: Browser pooling by default. Well documented, consistent PlaywrightEx API for advanced use cases. Early adopters ftw! #elixirlang

🎉 playwright_ex 0.2 released Focus: documentation and consistency Added docs and typespecs Ensured API consistency, especially 'Channel' modules (browser, frame, ...) #elixirlang hexdocs.pm/playwright_ex/

Tinkering: phoenix_test browser based tests with WebDriver bidi. Using butterbee lib (#gleamlang). github.com/germsvel/phoen… #elixirlang

I present: playwright_ex A simple Playwright client for #elixirlang. Experimental. Extracted from phoenix_test_playwright. PRs welcome! It's not comprehensive, because that's a daunting task (see playwright-elixir). But easy to extene hexdocs.pm/playwright_ex/

#ElixirConfEU call for talks is open (Apr 23-24, Malaga). I submitted: Changeset driven forms. Interested? Which aspects should I focus on? 👇 #elixirlang elixirconf.eu

Call for feedback: phoenix_test_plawright browser pooling Please run locally & in CI. Useful? Stable? Configurable to your needs? github.com/ftes/phoenix_t… #elixirlang

Surprising ⚡️: Performance of phoenix_test_playwright already pretty good. Compared to official javascript client. Many tests: browser re-use (experimental) brings slight boost. Unclear if worth the complexity. Do you need it? github.com/ftes/phoenix_t… #elixirlang

phoenix_test 💆 #elixirlang

"Let it Crash - Designing Robust Systems" Our talk included a Live Demo with audience participation. 👇 More details about what Marcus and I did at Dev Connect OWL. ftes.de/articles/2025-… #elixirlang

How do you find a misbehaving part of your software? Patience 🤣 Monitoring & Metrics (Prometheus, Grafana, cAdvisor, PRTG) Error Tracking & Logging (Sentry, Firebase, log files) Observability & Tracing (OpenTelemetry, metrics, distributed tracing) User Feedback

What are your building blocks for robust systems? Testing & Monitoring (unit/load tests, monitor, health checks) Fault Tolerance (redundancy, circuit breakers, loose coupling) Simple Architecture (KISS) Load Distribution (client-side calcs) "I would ask you" 🤣

We asked two questions at our talk "Let it Crash - Designing Robust Systems". What are your building blocks for robust systems? How do you find a misbehaving part of your software? Great answers in thread👇 My takeaway: The BEAM provides. #elixirlang #devconnectowl

PhoenixTestPlaywright 0.8 released - speed up refute_has - support bunx - support phoenix_test 0.8 And other quality of life improvements. #elixirlang

Common phoenix pitfalls when upgrading to LiveView 1.1 Tests may break in several ways. - HTML boolean attrs like 'checked' rendered differently - stricter CSS selectors due to lazy_html - phoenix_test needs fix #45 (unreleased)