@hapi/topo

What is @hapi/topo?

The @hapi/topo package is designed for managing dependencies and ordering items in a flexible way. It allows you to specify prerequisites for items and automatically sorts them based on these dependencies. This is particularly useful in scenarios where the order of operations is crucial, such as initializing plugins or tasks in a specific sequence.

What are @hapi/topo's main functionalities?

Adding items with dependencies

This feature allows you to add items to a Topo instance with specified dependencies. In the code sample, 'first' depends on 'second', so 'second' will come before 'first' in the output order.

{"const Topo = require('@hapi/topo');
const topo = new Topo();
topo.add('first', { after: ['second'], group: 'a' });
topo.add('second', { group: 'b' });
console.log(topo.nodes); // Output will be in the order of dependencies, ['second', 'first']"}

Grouping and ordering

This feature demonstrates how to group items and ensure they are processed in a specific order based on their group dependencies. Items can be added in groups and ordered relative to other groups.

{"const Topo = require('@hapi/topo');
const topo = new Topo();
topo.add(['first', 'second'], { group: 'a' });
topo.add('third', { group: 'b', after: ['a'] });
console.log(topo.nodes); // Output will respect the group order and dependencies, ['first', 'second', 'third']"}

Other packages similar to @hapi/topo

dag-map

dag-map is a simple DAG (Directed Acyclic Graph) implementation for JavaScript. Similar to @hapi/topo, it allows for specifying dependencies between items and ensures they are processed in order. However, dag-map focuses more on the DAG structure itself, without the specific grouping features that @hapi/topo provides.

dependency-graph

dependency-graph is another package that allows for managing dependencies between items in a graph structure. It provides functionality to add nodes and dependencies, and then sort or retrieve them in an order that respects their dependencies. Compared to @hapi/topo, dependency-graph offers a more detailed API for manipulating and querying the graph, but it might be more complex to use for simple ordering tasks.

README

@hapi/topo

Topological sorting with grouping support.

topo is part of the hapi ecosystem and was designed to work seamlessly with the hapi web framework and its other components (but works great on its own or with other frameworks). If you are using a different web framework and find this module useful, check out hapi – they work even better together.

Visit the hapi.dev Developer Portal for tutorials, documentation, and support

Useful resources

• Documentation and API
• Version status (builds, dependencies, node versions, licenses, eol)
• Changelog
• Project policies
• Free and commercial support options