escomplex

escomplex

THIS PROJECT IS (kind of) BRAND NEW AND NOT SAFE TO USE YET! :)

A library for reporting code complexity metrics in Mozilla-format abstract syntax trees.

• [Metrics][#metrics]
• [Abstract syntax trees][#abstract-syntax-trees]
• [Installation][#installation]
• [Usage][#usage]
• [Related projects][#related-projects]
• [Development][#development]
• [License][#license]

Metrics

Currently the library reports on:

• lines of code;
• number of parameters;
• cyclomatic complexity;
• Halstead metrics;
• maintainability index;
• dependencies (CommonJS and AMD);
• first-order density.

Abstract syntax trees

Mozilla's Parser API has become a de-facto standard for the in-memory data representation of parsed JavaScript programs. It defines an abstract syntax tree format composed of objects that publish their type information, allowing consuming programs to easily navigate those trees using generic logic.

By accepting a syntax tree in such a widely supported format, escomplex is decoupled from a specific input language. Any language that compiles to JavaScript and has a conforming parser can be the subject of complexity analysis by this library.

Some examples of conforming parsers are:

• Esprima;
• Acorn;
• CoffeeScriptRedux;
• LiveScript;

Installation

The library is published on npm under the name escomplex. To install, you can add it to the dependencies in your package.json file or simply run:

npm install escomplex

Usage

You can load escomplex in your own code by calling require:

var escomplex = require('escomplex');

It exports one function, called analyse:

var result = escomplex.analyse(ast, options);

The first argument, ast, must be either an abstract syntax tree as defined by Mozilla's Parser API or an array of said syntax trees.

The second argument, options, is an optional object containing properties that modify some of the complexity calculations:

• options.logicalor: Boolean indicating whether operator || should be considered a source of cyclomatic complexity, defaults to true.
• options.switchcase: Boolean indicating whether switch statements should be considered a source of cyclomatic complexity, defaults to true.
• options.forin: Boolean indicating whether for...in loops should be considered a source of cyclomatic complexity, defaults to false.
• options.trycatch: Boolean indicating whether catch clauses should be considered a source of cyclomatic complexity, defaults to false.
• options.newmi: Boolean indicating whether the maintainability index should be rebased on a scale from 0 to 100, defaults to false.

If a single abstract syntax tree object is passed in the ast argument, the result will be a report object detailing the complexity of that syntax tree. If ast is an array, the result will be an array of complexity reports.

TODO: Properties on the returned object

Related projects

TODO

Development

TODO

What license is it released under?

MIT