@arcjet/sprintf

@arcjet/sprintf

Arcjet platform-independent replacement for util.format.

This package is platform-independent in order to support multiple runtimes in varying environments, such as Edge Runtime, Node.js, Bun, Deno, and Cloudflare Workers.

• npm package (@arcjet/sprintf)
• GitHub source code (sprintf/ in arcjet/arcjet-js)

What is this?

This is an internal utility to help us format log messages. It’s a fork of pinojs/quick-format-unescaped. We chose to fork so that we can maintain as much compatibility as possible while being more restrictive.

When should I use this?

You should not use this but use pinojs/quick-format-unescaped or one of the alternatives instead. This package matches our current needs which are likely different from yours.

Install

This package is ESM only. Install with npm in Node.js:

npm install @arcjet/sprintf

Use

import { sprintf } from "@arcjet/sprintf";

console.log(sprintf("Hello %s", "world")); // => "Hello world"
console.log(sprintf("1 %i %d", 2, 3.0)); // => "1 2 3"

API

This package exports the identifier sprintf. The default export is also sprintf.

This package exports no TypeScript types.

sprintf(template, …values)

Formats a string by replacing placeholders with the provided values. See Substitutions below for the supported placeholder types.

Parameters

• template (string) — the format string with placeholders
• values (Array<unknown>) — values to interpolate into the template

Returns

The formatted string (string).

Substitutions

Substitutions will be made for the following character sequences if the matching argument conforms to the type. For example, "%d" will only be replaced by a number, not a string or object.

Object substitution supports any value that is not undefined.

• %d | %f - Replaced if provided with a number.
• %i - Replaced if provided with a number after Math.floor is called on it.
• %O | %o | %j - Replaced if provided with any value after JSON.stringify is called on it. Objects with circular references will be replaced with [Circular]. Functions will be replaced with the function name or <anonymous> if unnamed.
• %s - Replaced if provided with a string.
• %% - Replaced by the literal % character.

License

Apache License, Version 2.0 © Arcjet Labs, Inc.

Derivative work based on quick-format-unescaped licensed under MIT © David Mark Clements. Our work is more restrictive while maintaining as much compatibility as possible.