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I Built a Library That Scrapes and Slims Down YAML Files

I created an npm module that strips YAML files down to size. It can delete specific elements or replace them with empty values.

Published here:

• npm / yaml-scraper
• GitHub / yaml-scraper

The word "scraper" means something like "to scrape off." It even has a Travis CI badge!

What Can It Do?

Given a YAML file like this:

sample:
 hoge: I want to delete this
 fuga: I want to empty this
 hogehoge:
 hoge: I want to delete this too
 fuga: I want to empty this too
 hogera: Leave this as-is
 piyopiyo:
 piyo: I want to delete the parent of this

The library can:

• Delete elements whose key is hoge
• Keep elements whose key is fuga, but replace the value with an empty string
• Delete the parent element of the element whose key is piyo

The resulting output is:

sample:
 fuga: ''
 hogehoge:
 fuga: ''
 hogera: Leave this as-is

Unnecessary elements are stripped away, making the YAML file much lighter. It works at any nesting depth!

Why I Built It

I use Swagger to generate API documentation sites. When I tried to import a Swagger file into Amazon API Gateway, I got a size limit error.

To work around that, I built this library to strip out unnecessary elements from the YAML.

Installation

Node.js is required.

If Node.js is installed, run:

npm install yaml-scraper

Sample Code

Here's the sample code for the operations described above:

// Load libraries
const fs = require('fs');
const scraper = require('yaml-scraper');

// Read the YAML file
const input = fs.readFileSync('./sample.yaml', 'utf8');

// Delete 'hoge', empty 'fuga', delete parent of 'piyo'
const output = scraper(input)
 .delete('hoge')
 .empty('fuga')
 .deleteParent('piyo')
 .toString();

// Print the result
console.log(output);

As you can see, delete, empty, and deleteParent are provided as a method chain.

Closing

The following articles were helpful during development — thank you for the clear explanations!

• Building a Method Chain in JavaScript
• Your First npm Package Publication