FindParent CLI

Overview

FindParent is a command-line tool to navigate a dynamically built file system and find the closest parent directory that contains two given file paths. The file system is constructed based on the input paths provided by the user.

Getting Started

Prerequisites

• Node.js (version 12.x or higher)
• npm
• Jest (for running tests)

Installation

1. Clone the repository:

git clone https://github.com/yourusername/findparent-cli.git
cd findparent-cli

2. Install the dependencies:

npm install

3. Build the project:

npm run build

Usage

Running the CLI

To find the common parent of two file paths, use the following command:

npm start "<path1>" "<path2>"

For example:

npm start "a/b/c" "a/b/d"

This command will output:

Common parent: b

Example File System

Given the file system structure:

root
├── a
│   ├── c
│   └── d
└── b

npm start "a/c" "a/d" will output Common parent: a

npm start "a/c" "b" will output Common parent: root

Development

Adding New Tests

To add new tests, update the test/fileSystem.spec.ts file. You can run the tests using:

npm test

Building the File System

The file system is dynamically built from the paths provided. The buildFileSystem function handles the creation of the file nodes and their hierarchical structure.

Explanation of the findParent Function

The findParent function leverages Depth-First Search (DFS) to find the common parent directory of two given files. Here's how it works:

findPath Function

1. Start from the Root: The function begins at the root node and pushes it onto the path.
2. Check if Root is the Target: If the current node (root) is the target node, the function returns true.
3. Recursively Search Children: If the current node is not the target, the function recursively searches each child.
   • If any recursive call returns true, indicating the target was found in that subtree, the current call also returns true.
   • If no children lead to the target, the current node is removed from the path (backtracking) and the function returns false.
4. Path Construction: By the end of the function, if the target is found, path contains the sequence of nodes from the root to the target.

findParent Function

1. Find Paths: The function uses findPath to get the paths from the root to both target files (file1 and file2).
2. Compare Paths: The function then compares these paths to find the deepest common ancestor.
   • It iterates through both paths until the nodes differ.
   • The last common node before the paths diverge is the closest common parent.