What is Gremlint?

Gremlint is a code formatter which parses Gremlin queries and rewrites them to adhere to certain styling rules. It does so by parsing the query to an abstract syntax tree, and reprinting it from scratch.

But why?

• To make Gremlin queries more readable
• To make your queries more beautiful
• To act as a “living” style guide

Install Gremlint as a JavaScript / TypeScript package

Since Gremlint is not yet “published”, it has to be installed from its GitHub repo:

npm install OyvindSabo/gremlint#master

Basic example

import { formatQuery } from 'gremlint';

const unformattedQuery = `g.V().has('person', 'name', 'marko').shortestPath().with(ShortestPath.target, __.has('name', 'josh')).with(ShortestPath.distance, 'weight')`;

const formattedQuery = formatQuery(unformattedQuery);

console.log(formattedQuery);

g.V().
  has('person', 'name', 'marko').
  shortestPath().
    with(ShortestPath.target, __.has('name', 'josh')).
    with(ShortestPath.distance, 'weight')

Override default max line length

The default max line length is 80, but it can easily be overridden.

import { formatQuery } from 'gremlint';

const unformattedQuery = `g.V().has('person', 'name', 'marko').shortestPath().with(ShortestPath.target, __.has('name', 'josh')).with(ShortestPath.distance, 'weight')`;

const formattedQuery = formatQuery(unformattedQuery, { maxLineLength: 50 });

console.log(formattedQuery);

g.V().
  has('person', 'name', 'marko').
  shortestPath().
    with(
      ShortestPath.target,
      __.has('name', 'josh')).
    with(ShortestPath.distance, 'weight')

Other formatting options

import { formatQuery } from 'gremlint';

const unformattedQuery = `g.V().has('person', 'name', 'marko').shortestPath().with(ShortestPath.target, __.has('name', 'josh')).with(ShortestPath.distance, 'weight')`;

const formattedQuery = formatQuery(unformattedQuery, {
  indentation: 4, // default: 0
  maxLineLength: 40, // default: 80
  shouldPlaceDotsAfterLineBreaks: true, // default: false
});

console.log(formattedQuery);

    g.V()
      .has('person', 'name', 'marko')
      .shortestPath()
        .with(
          ShortestPath.target,
          __.has('name', 'josh'))
        .with(
          ShortestPath.distance,
          'weight')

Just looking for an online Gremlin query formatter?

https://gremlint.com is a website which utilizes the Gremlint library to give users an online “living” style guide for Gremlin queries. It also serves as a platform for showcasing the features of Gremlint. Its source code is available here.

For contributors

Install dependencies

npm install

Lint source files

npm run lint

Format source files

npm run format

Run tests

npm test

Compile the TypeScript source code

npm run build

Bump version

npm version [major | minor | patch]