SDP-Analyzer

An analyzer to implement the SDP (Stable Dependencies Principle) theory. You can quickly analyze your npm package here: https://sdp-analyzer.vercel.app/

Here's just a simple quote, the theory is as follows:

Fan-in = Number of classes outside the component which depends on the component. Fan-out = Number of classes outside the component which the component depends on.

Instability = Fan-out / (Fan-in + Fan-out).

Example: Component A has three classes from component B that depends on it (Fan-in = 3). Component A also depends on two classes from component C (Fan-out = 2). Therefore, the instability value for component A is 2/(3+2) = 2/5.

For more details, please read: My blog.

Tip

The analyzing rule above based on the number of dependencies or dependents is a simple evaluation.

I think the rules could be much more exact, such as using more data from GitHub stars or NPM downloads to evaluate again. In that case, it should be called the "Stability Analyzer".

Installation

npm i sdp-analyzer -g

Usages

CLI

To analyze local package

sdp-analyzer analyze ./examples

To analyze NPM package

sdp-analyzer analyze react,vue,svelte,audio-analyser-cli

Npx

npx sdp-analyzer analyze react,vue,svelte,audio-analyser-cli

API Reference

const { analyze } = require("sdp-analyzer");
try {
  const deps = await analyze("react");
} catch (error) {
  //  handle error
}

The results are similar to the following:

[
  {
    "name": "react",
    "in": 195657,
    "out": 1,
    "instability": 0.000005110958918112216,
    "label": "Stable"
  }
]