Smartass – TypeScript test assertions with type-narrowing signatures
Type-narrowing assertions that Jest and Vitest's expect() can't provide.
Expressive assertions for Go. Make your tests readable, elegant, and easy to debug.
Yet another Go assertion library competing directly with testify's established ecosystem.
Go developers writing unit tests
testify · assert · gomega
The core idea is still the same — when a test fails, you should immediately know why without having to add debug prints.
Type-narrowing assertions that Jest and Vitest's expect() can't provide.
Catches silent UI regressions that Sentry and RUM dashboards completely miss.
Asserts SLOs against Prometheus metrics instead of flaky wall-clock timing in CI.
The ? operator macro attaching breakpoints to error propagation is genuinely clever.
Pytest syntax for LLM testing avoids LLM-judge cost, but feature parity vs. LangSmith and Braintrust unproven.
I built Attest because every team I've seen building AI agents ends up writing the same ad-hoc pytest scaffolding — checking if the right tools were called, if