Dendrologist 🌲

This library provides a set of functions to manipulate a tree data structure where each node has an id and a list of children. The tree is represented by a Node interface:

interface Node {
  id: string;
  [key: string]: any;
}

Installation

npm install dendrologist
yarn install dendrologist
pnpm install dendrologist

Functions

export function getNodeById(
  node: Node | null | undefined,
  id: string,
  childrenKey: string = "children"
): Node | null {
  // Implementation details...
}

This function takes a node (the root of the tree), an id to search for, and an optional childrenKey that specifies the property name for the children array in each node. It performs a depth-first search (DFS) to find the node with the matching id and returns it. If the node is not found, it returns null.

export function updateNode(
  node: Node,
  id: string,
  newData: Node,
  childrenKey: string = "children"
): Node | null {
  // Implementation details...
}

This function takes a node, an id to identify the node to update, newData containing the updated properties, and an optional childrenKey to specify the property name for the children array. It performs a DFS to find the node with the matching id, updates its properties with newData, and returns the updated node. If the node is not found, it returns null.

export function deleteNode(
  node: Node | null | undefined,
  id: string,
  childrenKey: string = "children"
): Node | null {
  // Implementation details...
}

This function takes a node, an id to identify the node to delete, and an optional childrenKey to specify the property name for the children array. It performs a DFS to find the node with the matching id, removes it from its parent's children array, and returns the modified tree. If the node is not found, it returns null.

export function addNode(
  tree: Node | null | undefined,
  parentId: string,
  newNode: Node,
  position: number,
  childrenKey: string = "children"
): Node {
  // Implementation details...
}

This function takes a tree (the root of the tree), a parentId to identify the parent node where the new node will be added, newNode containing the properties of the new node, position specifying the index at which the new node should be inserted, and an optional childrenKey to specify the property name for the children array. It performs a DFS to find the parent node with the matching parentId, inserts the newNode at the specified position in the parent's children array, and returns the modified tree.

export function moveNode(
  node: Node | null | undefined,
  nodeId: string,
  newParentId: string,
  childrenKey: string = "children"
): Node | null {
  // Implementation details...
}

This function takes a node (the root of the tree), a nodeId to identify the node to move, a newParentId to identify the new parent node, and an optional childrenKey to specify the property name for the children array. It performs a DFS to find the node with the matching nodeId, removes it from its current parent's children array, and adds it to the children array of the node with the matching newParentId. It returns the modified tree. If either the node or the new parent is not found, it throws an error.

Error Handling

All functions throw an error if any of the input parameters are null or undefined. The moveNode and addNode functions also throw an error if the target parent node is not found in the tree.

Performance

All functions use an iterative DFS approach with a stack for tree traversal, which is efficient in terms of memory usage. They also create a deep copy of the tree before making modifications, ensuring that the original tree is not mutated.