refurb-json-minify

refurb-json-minify

A small plugin for Refurb aimed at minifying JSON outputs.

Why is this important?

JSON is a widely used format for data exchange, whether that be APIs talking over the internet, metadata being stored in a database, or config files stored on a user's filesystem. Although CPU and harddrive space is getting cheaper and cheaper, it isn't free, and being mindful of resources can lead to faster and more efficient programs.

Supported Checks

JMIN100: Use separators

The json.dump and json.dumps functions allow for an optional separators field which specifies what characters to use for colons (:) and commas (,) in the JSON output. Normally there is whitespace after these characters, but you can change this to use a more compact format.

Here is a simple example comparing the output of json.dumps() with and without separators specified:

import json

data = {
  "hello": "world",
  "numbers": [1, 2, 3, 4],
}

a = json.dumps(data)
b = json.dumps(data, separators=(",", ":"))

print(f"{len(a)=}", f"{len(b)=}")

When we run this, we get:

len(a)=43 len(b)=37

By reducing the whitespace in our JSON output we where able to shave off 6 bytes, or about 16% in this example.

JMIN101: Don't json.dump() integers

Don't call json.dump() on integers, use str() instead since they share the same representation.