babel-plugin-detective

2.0.0 verified Sat Apr 25 auth: no javascript

A Babel plugin (versions 5 & 6) that scans the AST for import statements and require() calls, extracting dependency strings and location data. Works with both ESM imports and CommonJS requires, including dynamic expressions. Metadata is stored on the Babel result and can be retrieved via a convenience method. It provides fine-grained filtering via options like `import`, `export`, `require`, and `generated`. Stable version is 2.0.0, which only supports Babel 5/6 (not Babel 7+). Compatible with Node >=0.10.0.

Common errors

error Error: Cannot find module 'babel-core' ↓

cause babel-core is a peer dependency that must be installed alongside babel-plugin-detective.

fix

Run: npm install babel-core babel-plugin-detective

error TypeError: detective.metadata is not a function ↓

cause The import style is incorrect; detective is a CommonJS module that exports a function with a property, not an ES module.

fix

Use const detective = require('babel-plugin-detective'); instead of import.

error Error: Plugin 0 specified in "plugins" provided an invalid property of type "undefined" ↓

cause The plugin is being used in Babel 7 which expects @babel/plugin-* format. babel-plugin-detective only works with Babel 5/6.

fix

Upgrade to babel-core version 6.x.x or use a different detective plugin for Babel 7.

Warnings

breaking This plugin does not support Babel 7+. Use at least babel-core 5 or 6. ↓

fix If you need Babel 7, use @babel/traverse with a custom visitor or switch to a different package like detective.

deprecated Node.js >=0.10.0 is extremely outdated. Modern installations may encounter issues with missing modules or security vulnerabilities. ↓

fix Use Node.js >=12.0.0, but note that the plugin may still work. If it fails, try using @babel/plugin-proposal-detective or a different dependency scanner.

gotcha When using options.generated: true, you may get duplicate entries if ES2015 imports are present, because imports are also detected separately. ↓

fix Set import: false and require: true to only capture generated require() calls, or deduplicate manually.

gotcha The metadata method requires the full Babel result object, not just the metadata property. Passing result.metadata will not work. ↓

fix Always pass the result object returned by babel.transform* (e.g., const meta = detective.metadata(transformResult));

gotcha Dynamic require expressions are captured only as location data, not strings. The plugin does not evaluate expressions. ↓

fix Use a static analysis tool like detective (the original) or escodegen to evaluate simple expressions, or accept that dynamic dependencies are not resolved.

Install

npm install babel-plugin-detective

yarn add babel-plugin-detective

pnpm add babel-plugin-detective

Imports

default
wrong
```
import detective from 'babel-plugin-detective';
```
correct
```
const detective = require('babel-plugin-detective');
```
This package is CommonJS only; there is no default ESM export. It can be required in an ES module context using createRequire.
metadata
wrong
```
const metadata = babelResult.metadata.detective;
```
correct
```
const metadata = detective.metadata(babelResult);
```
metadata is a static method on the detective function, not on the result object. The result.metadata.requires is available, but the convenience method normalizes it.

options

wrong

// Using with Babel 7 won't work; this plugin only supports Babel 5/6.

correct

import babel from 'babel-core';
const result = babel.transformFileSync('file.js', {
  plugins: [['detective', { import: false }]]
});

Options are passed as the second element of the plugin array in Babel 6, or via extra.detective in Babel 5.

Quickstart

Uses babel-plugin-detective to extract all string module names from import and require statements in a code snippet.

const babel = require('babel-core');
const detective = require('babel-plugin-detective');

const code = `
const fs = require('fs');
import path from 'path';
`;

const result = babel.transformSync(code, {
  plugins: [[detective, { import: true, require: true }]]
});

const requires = detective.metadata(result);
console.log(requires.strings); // ['fs', 'path']
console.log(requires.expressions); // []