pip-requirements-js/README.md

A robust parser for requirements.txt files

# pip-requirements-js

A pure JavaScript/TypeScript parser for pip requirements files. Process requirements.txt, constraints.txt, or pip-tools' requirements.in – all without ever leaving JavaScript.

pip-requirements-js strictly adheres to [pip's documentation of the requirements file format](https://pip.pypa.io/en/stable/reference/requirements-file-format/), along with [PEP 508 – Dependency specification for Python Software Packages](https://peps.python.org/pep-0508/). You can sleep well knowing that no dependency will be misinterpreted (if that ever keeps you up at night).

## API

To extract all the requirements from a given file, use
```typescript
parsePipRequirementsFile(fileContent: string): Requirement[]
```

To extract a requirement from a given line, use
```typescript
parsePipRequirementsLine(lineContent: string): Requirement | null
```
(note that `null` will be returned if the line is empty)

In both cases a `RequirementsSyntaxError` will be thrown if the provided content contains invalid syntax.

To make use of the resulting data, look up what `Requirement` is made up of in [`types.ts`](https://github.com/Twixes/pip-requirements-js/blob/main/src/).

## Internals

pip-requirements-js is built with the robust parser generator [Ohm.js](https://github.com/ohmjs/ohm) – the core of this library is the [pep-508.ohm](https://github.com/Twixes/pip-requirements-js/blob/main/src/pep-508.ohm) grammar, which is an Ohm port of [PEP 508's complete dependency specification grammar](https://peps.python.org/pep-0508/#complete-grammar) (originally defined for Parsley), with some pip-specific additions (such as the `-r extra-requirements.txt` syntax). This ensures the greatest possible compatibility with what pip itself does.