Merge commit '3c60637c1a27da8ba66888de518d58d5707801f2' as 'repos/effect-smol'

repos/effect-smol/.patterns/testing.md

@@ -0,0 +1,44 @@
+# Testing Patterns
+
+## Testing Framework Selection
+
+Use `it.effect` for tests that return Effects.
+
+```typescript
+import { assert, describe, it } from "@effect/vitest"
+import { Effect } from "effect"
+
+it.effect("should work with Effects", () =>
+  Effect.gen(function*() {
+    const result = yield* someEffect
+    assert.strictEqual(result, expectedValue)
+  }))
+```
+
+Use regular `it` for pure synchronous TypeScript functions.
+
+```typescript
+import { assert, describe, it } from "@effect/vitest"
+
+it("should work with pure functions", () => {
+  const result = pureFunction(input)
+  assert.strictEqual(result, expectedValue)
+})
+```
+
+## Testing Rules
+
+- Never use `Effect.runSync` in tests
+- Never use `expect` from Vitest; use `assert` methods instead
+- Always use `TestClock` for time-dependent operations
+- Group related tests using `describe`
+
+## Type-Level Tests
+
+Type-level tests are located in `packages/*/typetest/` and use Tstyche.
+
+Run targeted type-level tests with:
+
+```sh
+pnpm test-types <filename>
+```