A node was built with inconsistent transport fields — a programming invariant, thrown at declaration (like DuplicateHyperlinkKey) so a malformed node fails loudly there instead of as a confusing dial/serve failure later.
export class class MalformedNodeclass MalformedNode {
message: string;
name: string;
stack: string;
cause: unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
_tag: Tag;
key: string;
reason: string;
}
A node was built with inconsistent transport fields — a programming invariant, thrown at
declaration (like
DuplicateHyperlinkKey
) so a malformed node fails loudly there instead of
as a confusing dial/serve failure later.
MalformedNode extends import DataData.const TaggedError: <"MalformedNode">(tag: "MalformedNode") => new <A>(args: VoidIfEmpty<{ readonly [P in keyof A as P extends "_tag" ? never : P]: A[P]; }>) => YieldableError & {
readonly _tag: "MalformedNode";
} & Readonly<A>
Creates a tagged error class with a _tag discriminator.
When to use
Use when you need domain errors with discriminated-union handling.
Details
Like
Error
, but instances also carry a readonly _tag property,
enabling Effect.catchTag and Effect.catchTags for tag-based recovery.
The _tag is excluded from the constructor argument. Yielding an instance
inside Effect.gen fails the effect with this error.
Example (Recovering by tag)
import { Data, Effect } from "effect"
class NotFound extends Data.TaggedError("NotFound")<{
readonly resource: string
}> {}
class Forbidden extends Data.TaggedError("Forbidden")<{
readonly reason: string
}> {}
const program = Effect.gen(function*() {
return yield* new NotFound({ resource: "/users/42" })
})
const recovered = program.pipe(
Effect.catchTag("NotFound", (e) =>
Effect.succeed(`missing: ${e.resource}`))
)
TaggedError("MalformedNode")<{
readonly key: stringkey: string;
readonly reason: stringreason: string;
}> {
override get MalformedNode.message: stringmessage() {
return `Node "${this.key: stringkey}" is malformed: ${this.reason: stringreason}.`;
}
}