---
title: "validate"
description: "Validate the integrity of a tree structure, returning whether it is valid along with a list of errors describing any problems."
canonical_url: "https://core.mhaibaraai.cn/en/docs/transformers/tree/validate"
---
# validate

> Validate the integrity of a tree structure, returning whether it is valid along with a list of errors describing any problems.

## Usage

The `validate` method checks whether a tree structure is valid. It primarily checks for two issues:

1. Whether there are duplicate node `id`s.
2. Whether there are circular references (i.e., a node is an ancestor of itself).

```ts [example.ts]
import { Tree } from '@movk/core'

// Valid tree
const validTree = [{ id: 1, children: [{ id: 2 }] }]
Tree.validate(validTree) // no error thrown

// Invalid tree (duplicate IDs)
const invalidTree1 = [{ id: 1 }, { id: 1 }]
try {
  Tree.validate(invalidTree1)
}
catch (e) {
  console.error(e.message) // "Duplicate ID found: 1"
}

// Invalid tree (circular reference)
const node1 = { id: 1 }
const node2 = { id: 2, children: [node1] }
node1.children = [node2]
const invalidTree2 = [node1]
try {
  Tree.validate(invalidTree2)
}
catch (e) {
  console.error(e.message) // "Circular reference detected in node ID: 2"
}
```

## API

`validate<T extends TreeNode>(tree: T[], config?: TreeConfig): void`

### Parameters

**tree** (`T[]`) *required*: The source tree array.

**config** (`TreeConfig`): Configuration object for customizing the id, pid, children key names in the tree structure.Optional. The key name for the node's unique identifier. Defaults to "id".Optional. The key name for the node's parent identifier. Defaults to "pid".Optional. The key name for the children array. Defaults to "children".

### Returns

If the tree structure is invalid, this method throws an `Error`.

## Changelog

See commit history for [src/transformers/tree/validate.ts](https://github.com/mhaibaraai/movk-core/commits/main/src/transformers/tree/validate.ts).

---

- [GitHub](https://github.com/mhaibaraai/movk-core/blob/main/src/transformers/tree/validate.ts)


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