This is a simple A* Pathfinding Algorithm Visualized using React and Typescript. You Can Check the Up and Running Demo!
If you're intrested in A* Algorithm, I'd suggest you to watch This Youtube Playlist By Sebastian Lague. The Playlist is for making the Algorithm in Unity, but with Watching this Playlist, you can understand a lot of the ideas and convert them to your preffered Programming languages.
If you want to write an A* Algorithm in Typescript, you can use parts of this repo which are useful for you. the Main classes of this repo are the Node class, Grid class, the PathFinding class as well as the Heap class. (You Can remove the heap and uncomment lines #11,-33 and comment lines #19, #12 on the PathFinding File. But I'd Suggest not doing that because the Heap class Increases the Efficiency and the Speed of the Algorithm by around x4.