missing-return-yield-star.md

missingReturnYieldStar

Suggests using return yield* for Effects that never succeed

Property	Value
Category	Correctness
Default severity	error
Fixable	Yes
Effect versions	v3, v4
Diagnostic codes	TS377006
Language Service name	missingReturnYieldStar
Oxlint name	effecttsgo/missing-return-yield-star

Preview

import * as Effect from "effect/Effect"

export const preview = Effect.gen(function*() {
  yield* Effect.log("before")
  yield* Effect.fail("boom")
/**
  ^^^^^ effecttsgo(missing-return-yield-star): This Effect never succeeds; using `return yield*` preserves a definitive generator exit point for type narrowing and tooling support.
*/
})

Language Service Configuration

See the Language Service setup guide for installation instructions.

{
  "$schema": "./node_modules/@effect/tsgo/schema.json",
  "compilerOptions": {
    "plugins": [
      {
        "name": "@effect/language-service",
        "diagnosticSeverity": {
          "missingReturnYieldStar": "warning"
        }
      }
    ]
  }
}

Oxlint Configuration

See the Oxlint setup guide for installation and patching instructions.

{
  "$schema": "./node_modules/@effect/tsgo/oxlint-schema.json",
  "options": {
    "typeAware": true
  },
  "plugins": ["effecttsgo"],
  "rules": {
    "effecttsgo/missing-return-yield-star": "warn"
  }
}