What is Gremlint?

Gremlint is a code formatter, from Apache TinkerPop™ 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

npm install gremlint

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.