Build Errors

BuildError<E> is the normalized error type returned by build and use.

import type { BuildError } from '@fuiste/dependencies'

missing_service

type MissingServiceError = {
  readonly _tag: 'missing_service'
  readonly tag: Context.Tag.Any
  readonly path: readonly string[]
}

The graph required a service that was not present in the environment.

duplicate_service

type DuplicateServiceError = {
  readonly _tag: 'duplicate_service'
  readonly tag: Context.Tag.Any
  readonly path: readonly string[]
}

Two outputs tried to define the same tag during strict merge.

circular_dependency

type CircularDependencyError = {
  readonly _tag: 'circular_dependency'
  readonly dependency: string
  readonly path: readonly string[]
}

The evaluator encountered the same dependency under the same environment while it was already active.

construction_failed

type ConstructionFailedError<E> = {
  readonly _tag: 'construction_failed'
  readonly dependency: string
  readonly path: readonly string[]
  readonly cause: 'error' | 'defect'
  readonly error?: E
  readonly defect?: unknown
}

cause: 'error' means a constructor returned Result.err. cause: 'defect' means something threw or rejected.