effect-io-ai

Package: effect
Module: SchemaGetter

SchemaGetter.checkEffect

Creates a getter that validates a value using an effectful check function.

When to use

Use when you need a schema getter to validate a decoded value (e.g. check a constraint or call an external service).

• The validation may be asynchronous or require Effect services.

Details

• Only runs when input is Some — None passes through.
• The check function returns a validation result:
  • undefined or true — value is valid, passes through.
  • false or a string — value is invalid, fails with an Issue.
  • An Issue object — fails with that issue directly.
  • { path, issue } — fails with a nested path issue (issue may be a message string or a full SchemaIssue.Issue).
• Does not transform the value — input and output types are the same.

Example (Validating effectfully)

import { Effect, SchemaGetter } from "effect"

const nonNegative = SchemaGetter.checkEffect<number>((n) =>
  Effect.succeed(n >= 0 ? undefined : "must be non-negative")
)

See

• transform when you need to change the value, not just validate
• fail for unconditional failure

Signature

declare const checkEffect: <T, R = never>(f: (input: T, options: SchemaAST.ParseOptions) => Effect.Effect<undefined | boolean | Schema.FilterIssue, never, R>) => Getter<T, T, R>

Source

Since v4.0.0