A journal/IO write failure surfaced by the storage layer's append path — the categorized,
catchable error that write methods honestly carry in their error channel. Wraps the underlying
journal/IO write cause. An encode/serialization mismatch stays a defect (orDie); this is only the
genuine write failure. Store.catchWriteErrors narrows it out (logs + swallows).
export class class StoreWriteErrorclass StoreWriteError {
name: string;
message: 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;
detail: string | undefined;
}
A journal/IO write failure surfaced by the storage layer's append path — the categorized,
catchable error that write methods honestly carry in their error channel. Wraps the underlying
journal/IO write cause. An encode/serialization mismatch stays a defect (orDie); this is only the
genuine write failure.
Store.catchWriteErrors
narrows it out (logs + swallows).
StoreWriteError extends import DataData.const TaggedError: <"StoreWriteError">(tag: "StoreWriteError") => new <A>(args: VoidIfEmpty<{ readonly [P in keyof A as P extends "_tag" ? never : P]: A[P]; }>) => YieldableError & {
readonly _tag: "StoreWriteError";
} & 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("StoreWriteError")<{
readonly cause: unknowncause: unknown;
readonly detail?: string | undefineddetail?: string;
}> {}