Uniswap V2 route (path) finder for two tokens, if given a set of pools

path-finder.js

class PathFinder {
    constructor(pairs) {
        this.graph = new Map()
        pairs.forEach((item) => {
            if (!this.graph.has(item[0])) {
                this.graph.set(item[0], new Array())
            }
            if (!this.graph.has(item[1])) {
                this.graph.set(item[1], new Array())
            }
            this.graph.get(item[0]).push(item[1])
            this.graph.get(item[1]).push(item[0])
        })
    }

    find(a, b) {
        this.start = a
        this.target = b
        this.visited = new Set()
        return this.dfs(this.start)
    }

    dfs(s) {
        const paths = new Array()
        if (s === this.target) {
            paths.push([s])
            return paths
        }
        if (this.visited.has(s)) {
            return paths
        }
        this.visited.add(s)

        this.graph.get(s).forEach((neighbour) => {
            this.dfs(neighbour).forEach((path) => {
                paths.push([s, ...path])
            })
        })

        this.visited.delete(s)
        return paths
    }
}

const pairs = [['a', 'b'], ['a', 'c'], ['b', 'd'], ['c', 'd']]
const pf = new PathFinder(pairs)
console.log(pf.find('b', 'd'))
console.log(pf.find('a', 'b'))
console.log(pf.find('a', 'd'))