Graph with Reflexivity
A lightweight JavaScript implementation of a directed graph where every node automatically has a self‑loop (reflexive edge).
The library is intentionally minimal and does not depend on any external graph libraries or Python code.
Features
- Automatic reflexivity – when a node is added, an edge from the node to itself is created.
- Directed edges – you can add edges in any direction.
- Simple API – add nodes, add edges, query edges, list nodes, list edges.
- Pure JavaScript – works in Node.js environments.
Installation
npm install graph-reflexivity
If you want to run the tests or develop locally, clone the repository and run
npm install.
Usage
const Graph = require('graph-reflexivity');
const g = new Graph();
// Add nodes
g.addNode('A');
g.addNode('B');
// Add directed edge A → B
g.addEdge('A', 'B');
// Reflexive edges are automatically added
console.log(g.hasEdge('A', 'A')); // true
console.log(g.hasEdge('B', 'B')); // true
// Query
console.log(g.getNeighbors('A')); // ['A', 'B']
console.log(g.nodes()); // ['A', 'B']
console.log(g.edges()); // [['A', 'A'], ['B', 'B'], ['A', 'B']]
API
| Method | Description |
|---|---|
addNode(node) |
Adds a node and its reflexive edge. |
addEdge(from, to) |
Adds a directed edge; missing nodes are created automatically. |
hasEdge(from, to) |
Returns true if an edge exists. |
getNeighbors(node) |
Returns an array of all neighbors of node. |
nodes() |
Returns an array of all nodes. |
edges() |
Returns an array of [from, to] pairs for all edges. |
Testing
The project uses Jest for unit tests.
npm test
All tests are located in the tests/ directory.
License
MIT © Your Name
Feel free to open issues or pull requests if you find bugs or want to add features.