Class: ExpectedError<TCode, TValues>

Defined in: index.ts:84

Base class for expected errors: outcomes an operation anticipates and handles — invalid input, a missing resource, a degraded state the caller already reacted to. They still reach the caller, so the message is shown; they are just not faults, and an error tracker must not open an issue for them. Bugs, infrastructure failures and unexpected third-party errors stay a plain Error.

Extend it to add your own kinds:

class PaymentDeclinedError extends ExpectedError {}

name defaults to the subclass's constructor name. A minifier that renames classes changes it too, so a subclass whose name is matched downstream (an error type a client branches on) pins it with override name = '…'.

Extends

• Error

Extended by

• ValidationError
• NotFoundError

Type Parameters

Type Parameter	Default type
TCode extends string | undefined	string | undefined
TValues extends ExpectedErrorValues | undefined	ExpectedErrorValues | undefined

Implements

• ExpectedErrorLike

Constructors

Constructor

new ExpectedError<TCode, TValues>(message, options?): ExpectedError<TCode, TValues>

Defined in: index.ts:114

Parameters

Parameter	Type
message	string
options	ExpectedErrorOptions<TCode, TValues>

Returns

ExpectedError<TCode, TValues>

Overrides

Error.constructor

Properties

code

readonly code: TCode

Defined in: index.ts:103

A subclass narrows it through the type parameter, e.g. extends ExpectedError<'CARD_DECLINED' | 'CARD_EXPIRED'>.

Implementation of

ExpectedErrorLike.code

---

expected

readonly expected: true

Defined in: index.ts:97

The discriminant isExpectedError reads. A marker rather than instanceof because a bundler may inline its own copy of this class, and an error thrown from that copy is not an instance of yours.

Implementation of

ExpectedErrorLike.expected

---

messageRef?

optional messageRef?: MessageRef

Defined in: index.ts:112

Mutable: a boundary may attach it before rendering.

Implementation of

ExpectedErrorLike.messageRef

---

values

readonly values: TValues

Defined in: index.ts:109

A subclass narrows it per code through the type parameter, so the placeholders its copy interpolates are a checked contract.

Implementation of

ExpectedErrorLike.values