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createValidatedBuilder()

createValidatedBuilder<State>(initial): ValidatedBuilderDefinition<State, object>

Creates a builder with validation on build().

Same as createBuilder, but .done(validate) takes a validator. build() returns Result<State, string>.

Type Parameters​

State: State​

The product type being built

Parameters​

initial: State​

The initial state

Returns: ValidatedBuilderDefinition<State, object>​

A validated builder definition

Since​

2.4.0

Example​

const configBuilder = createValidatedBuilder({ host: "", port: 0 })
  .step("host", (s, host: string) => ({ ...s, host }))
  .step("port", (s, port: number) => ({ ...s, port }))
  .done((s) => s.host ? true : "host is required");

configBuilder().port(8080).build();         // Err("host is required")
configBuilder().host("localhost").build(); // Ok({ host: "localhost", port: 0 })

ValidatedBuilderDefinition<State, Methods>​

Interface

Validated builder definition that accumulates steps.

Since​

2.4.0

Type Parameters​

State: State​

The product state being built

Methods: Methods extends object​

Accumulated method signatures

Methods​

step()​

Adds a step to the builder.

Type Parameters​

K: K extends string​
Arg: Arg​

name: K
fn: (state, arg) => State
Returns: ValidatedBuilderDefinition<State, Methods & { [P in string]: (arg: Arg) => unknown }>

done()​

Finalizes with a validator. build() returns Result<State, string>.

validate: (state) => string | true — Returns true if valid, or an error message string
Returns: > (): ValidatedFinalBuilder<State, Methods>

Returns​

ValidatedFinalBuilder<State, Methods>

ValidatedFinalBuilder<State, Methods>​

Type

ValidatedFinalBuilder<State, Methods> = { [K in keyof Methods]: Methods[K] extends (arg: infer Arg) => unknown ? (arg: Arg) => ValidatedFinalBuilder<State, Methods> : never } & object

Builder with validated build() returning Result.

Type Declaration​

build(): () => Result<State, string>​

Returns Ok(state) if valid, Err(message) otherwise.

Returns: Result<State, string>​

current(): () => State​

Returns the current state without validation.

Returns: State​

Type Parameters​

State: State​

The product state being built

Methods: Methods extends object​

The step method signatures

Since​

2.4.0