detective

What is detective?

The 'detective' npm package is a module dependency analysis tool that helps developers to find out which modules are required in a given JavaScript file. It parses the file, extracts the 'require' statements, and returns a list of dependencies. This is particularly useful for tasks like bundling, minification, and understanding code dependencies.

What are detective's main functionalities?

Detect CommonJS dependencies

This feature allows you to extract all CommonJS dependencies (i.e., modules loaded via 'require') from a JavaScript file. The code reads a JavaScript file, uses detective to parse the file and logs the list of dependencies.

const detective = require('detective');
const fs = require('fs');
const content = fs.readFileSync('/path/to/js/file.js', 'utf8');
const dependencies = detective(content);
console.log(dependencies);

Detect ES6 module dependencies

Using 'detective-es6', a variant of detective tailored for ES6 modules, this feature parses files containing ES6 import statements to determine dependencies. The process involves reading the file, parsing it with detective-es6, and logging the dependencies.

const detective = require('detective-es6');
const fs = require('fs');
const content = fs.readFileSync('/path/to/es6/file.js', 'utf8');
const dependencies = detective(content);
console.log(dependencies);

Other packages similar to detective

precinct

Precinct is a tool similar to detective but with broader capabilities. It supports detecting dependencies from multiple module types including CommonJS, AMD, ES6, and TypeScript. Compared to detective, which requires different variants for different module systems, Precinct provides a more unified and versatile approach.

madge

Madge is a more comprehensive tool that builds on the functionality provided by detective. It not only finds dependencies but also creates visual graphs of module dependencies and can detect circular dependencies. This makes Madge suitable for larger projects where understanding the module structure visually can be particularly beneficial.

README

detective

find all calls to require() by walking the AST

example

strings

strings_src.js:

var a = require('a');
var b = require('b');
var c = require('c');

strings.js:

var detective = require('detective');
var fs = require('fs');

var src = fs.readFileSync(__dirname + '/strings_src.js');
var requires = detective(src);
console.dir(requires);

output:

$ node examples/strings.js
[ 'a', 'b', 'c' ]

methods

var detective = require('detective');

detective(src, opts)

Give some source body src, return an array of all the require() calls with string arguments.

The options parameter opts is passed along to detective.find().

var found = detective.find(src, opts)

Give some source body src, return found with:

• found.strings - an array of each string found in a require()
• found.expressions - an array of each stringified expression found in a require() call
• found.nodes (when opts.nodes === true) - an array of AST nodes for each argument found in a require() call

Optionally:

• opts.word - specify a different function name instead of "require"
• opts.nodes - when true, populate found.nodes
• opts.isRequire(node) - a function returning whether an AST CallExpression node is a require call
• opts.parse - supply options directly to acorn with some support for esprima-style options range and loc
• opts.ecmaVersion - default: 9

install

With npm do:

npm install detective

license

MIT

Changelog

5.1.0 - 2018-02-28

• Use acorn-node parser, which matches latest Node syntax support (https://github.com/browserify/detective/pull/78)
• Add basic cli: detective index.js outputs dependency names (https://github.com/browserify/detective/pull/51)