Registry / ai-ml / javascript-astar

javascript-astar

library0.4.1jsnpmunverified

The `javascript-astar` package provides an efficient implementation of the A* search algorithm in JavaScript for finding the shortest path on a grid. Currently at version 0.4.1, it has been optimized to use a Binary Heap, resulting in significant performance improvements over its original list-based approach. The library supports various graph configurations, including weighted nodes and diagonal movement. A weight of 0 for a node designates it as an impassable obstacle, and specific constraints apply to other weight values. It is primarily designed for browser environments via script tags, exposing global variables, and likely supports CommonJS environments for server-side usage, given its version and use of Grunt for tooling.

ai-ml

npm install javascript-astar

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · JAVASCRIPT-ASTAR

javascript-astar

ai-mljavascriptv0.4.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

astar

✓ import { astar } from 'javascript-astar'; // ESM const { astar } = require('javascript-astar'); // CJS

✗ import astar from 'javascript-astar'; // Incorrect for named export const astar = require('javascript-astar'); // This assigns the full module object, not just the 'astar' property

The `astar` object contains the main `search` function and `heuristics` object. In browser environments, `astar` is available as a global variable.

Graph

✓ import { Graph } from 'javascript-astar'; // ESM const { Graph } = require('javascript-astar'); // CJS

✗ new astar.Graph(); // Incorrect, `Graph` is a separate top-level export/global, not a property of `astar`

The `Graph` class is used to construct the grid for pathfinding. In browser environments, `Graph` is available as a global variable.

astar.heuristics.diagonal

✓ import { astar } from 'javascript-astar'; const diagonalHeuristic = astar.heuristics.diagonal;

✗ import { diagonal } from 'javascript-astar'; // Heuristics are nested under the `astar` object

Access specific heuristics as properties of the `astar.heuristics` object.

Demonstrates initializing a graph, performing basic A* search, and utilizing options for diagonal movement and custom node weights.

const { astar, Graph } = require('javascript-astar'); // For Node.js or bundlers; for browsers, `astar` and `Graph` are globals. // Basic usage: Find path on a grid without diagonal movement or custom weights. var graph = new Graph([ [1,1,1,1], [0,1,1,0], [0,0,1,1] ]); var start = graph.grid[0][0]; var end = graph.grid[1][2]; var result = astar.search(graph, start, end); console.log('Path (no diagonals, no weight):', result.map(node => `(${node.x},${node.y})`).join(' -> ')); // With diagonals: Enable diagonal moves and use the diagonal heuristic. var graphDiagonal = new Graph([ [1,1,1,1], [0,1,1,0], [0,0,1,1] ], { diagonal: true }); var startDiagonal = graphDiagonal.grid[0][0]; var endDiagonal = graphDiagonal.grid[1][2]; var resultWithDiagonals = astar.search(graphDiagonal, startDiagonal, endDiagonal, { heuristic: astar.heuristics.diagonal }); console.log('Path (with diagonals):', resultWithDiagonals.map(node => `(${node.x},${node.y})`).join(' -> ')); // With weights: Define custom movement costs for nodes (0 for walls). var graphWithWeight = new Graph([ [1,1,2,30], [0,4,1.3,0], [0,0,5,1] ]); var startWithWeight = graphWithWeight.grid[0][0]; var endWithWeight = graphWithWeight.grid[1][2]; var resultWithWeight = astar.search(graphWithWeight, startWithWeight, endWithWeight); console.log('Path (with weights):', resultWithWeight.map(node => `(${node.x},${node.y})`).join(' -> '));

Debug

Known issues

breakingThe internal algorithm was fundamentally changed from version 0.0.1 to use a Binary Heap, significantly improving performance over the original list-based approach. While this is a positive change, it represents a breaking change in internal implementation details.

fix

Upgrade to a newer version (0.4.1 or later) to benefit from the performance improvements. Review existing code for any direct reliance on the internal algorithm structures of versions prior to 0.0.1.

affects: <=0.0.1

gotchaNode weights in the graph have specific constraints: a weight of 0 marks a node as an impassable 'wall'. Weights cannot be negative, nor can they be fractional values exclusively between 0 and 1 (e.g., 0.5 is invalid). Decimal values greater than 1 are permitted.

fix

Ensure all graph node weights adhere to the specified rules: `0` for walls, `1` for standard passable nodes, or any number `> 1` (including decimals) for custom movement costs. Avoid negative weights or weights between 0 and 1 (exclusive).

affects: >=0.0.1

gotchaWhen included directly in browser environments via a `<script>` tag, the library exposes `astar` and `Graph` as global variables. This can lead to global namespace pollution, potentially conflicting with other scripts or libraries.

fix

To avoid global conflicts, consider using a module bundler (like Webpack or Rollup) to integrate `javascript-astar` as a module. Alternatively, encapsulate its usage within an Immediately Invoked Function Expression (IIFE) in browser scripts to limit variable scope.

affects: >=0.0.1

Errors

Common errors & fixes

ReferenceError: astar is not defined

The `astar` object was not correctly loaded or imported into the current scope. This typically happens if the script tag is missing in the browser or the CommonJS/ESM import is incorrect in Node.js/bundled environments.

fix

In browsers, ensure `<script src='astar.js'></script>` is present and loaded before your code. In Node.js, use `const { astar } = require('javascript-astar');` (for CJS) or `import { astar } from 'javascript-astar';` (for ESM).

TypeError: Graph is not a constructor

The `Graph` class was not properly imported or made available. In module environments, this often means it wasn't destructured correctly during the `require` or `import` statement.

fix

In module environments, ensure `Graph` is destructured from the package: `const { Graph } = require('javascript-astar');` or `import { Graph } from 'javascript-astar';`. In browsers, verify the `astar.js` script is loaded to expose the global `Graph`.

Invalid weight value (e.g., 'Weight cannot be negative', 'Weight cannot be between 0 and 1 exclusive')

A node in the `Graph` was initialized or modified with a weight value that violates the library's constraints (negative, or a decimal between 0 and 1 exclusively).

fix

Review the weights defined in your `Graph` grid. Valid weights are `0` (for walls), `1`, or any number `> 1` (including decimals). Adjust any invalid weight values accordingly.

Upgrade

Version history

0.4.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

10 hits · last 30 days

node

Resources

githubhttps://github.com/bgrins/javascript-astar ↗

packagehttps://www.npmjs.com/package/javascript-astar ↗

homepagehttp://bgrins.github.io/javascript-astar ↗