Function rewriteReplacementDependencies

packages/core/src/effect/layer-node.ts:286–319

(root: AnyNode, replacements: ReadonlyMap<string, AnyNode>)

}

function rewriteReplacementDependencies(root: AnyNode, replacements: ReadonlyMap<string, AnyNode>) {
  if (replacements.size === 0) return root
  const cache = new Map<AnyNode, AnyNode>()
  const visiting = new Set<AnyNode>()
  const stack: AnyNode[] = []

  const recur = (node: AnyNode, isRoot = false): AnyNode => {
    const target = isRoot ? node : (replacements.get(node.name) ?? node)
    const cached = cache.get(target)
    if (cached !== undefined || cache.has(target)) return cached!
    if (visiting.has(target)) {
      const start = stack.indexOf(target)
      throw new Error(
        `Cycle detected in layer tree: ${[...stack.slice(start), target].map((item) => item.name).join(" -> ")}`,
      )
    }

    visiting.add(target)
    stack.push(target)
    try {
      const dependencies = target.dependencies.map((dependency) => recur(dependency))
      const result = dependencies.every((dependency, index) => dependency === target.dependencies[index])
        ? target
        : { ...target, dependencies }
      cache.set(target, result)
      return result
    } finally {
      stack.pop()
      visiting.delete(target)
    }
  }

  return recur(root, true)
}

export function hasUnbound(root: Node<unknown, unknown, any>, source: AnyNode): boolean {
  if (source.kind !== "unbound") throw new Error(`Cannot check non-unbound layer node: ${source.name}`)