@visulima/fmt NPM

Install

npm install @visulima/fmt

yarn add @visulima/fmt

pnpm add @visulima/fmt

Usage

import { format } from "@visulima/fmt";

const formatted = format("hello %s %j %d", ["world", [{ obj: true }, 4, { another: "obj" }]]);

console.log(formatted); // hello world [{"obj":true},4,{"another":"obj"}] NaN

format(fmt, parameters, options)

fmt

A printf-like format string. Example: 'hello %s %j %d'

parameters

Array of values to be inserted into the format string. Example: ['world', {obj:true}]

options.stringify

Passing an options object as the third parameter with a stringify will mean any objects will be passed to the supplied function instead of an the internal tryStringify function. This can be useful when using augmented capability serializers such as fast-safe-stringify or fast-redact.

uses JSON.stringify instead of util.inspect, this means functions will not be serialized.

build

With the build function you can generate a format function that is optimized for your use case.

import { build } from "@visulima/fmt";

const format = build({
    formatters: {
        // Pass in whatever % interpolator you want, as long as it's a single character;
        // in this case, it's `t`.
        // The formatter should be a function that takes in a value and returns the formatted value.
        t: (time) => new Date(time).toLocaleString(),
    },
});

const formatted = format("hello %s at %t", ["world", Date.now()]);

console.log(formatted); // hello world at 1/1/1970, 1:00:00 AM

Format Specifiers

Format specifiers are dependent on the type of data-elements that are to be added to the string. The most commonly used format specifiers supported are:

Specifier	Description
%s	Converts all values except for `BigInt`, `-0` and `Object` to a string.
%d	Used to convert any value to `Number` of any type other than `BigInt` and `Symbol`.
%i	Used for all values except `BigInt` and `Symbol`.
%f	Used to convert a value to type `Float`. It does not support conversion of values of type `Symbol`.
%j	Used to add JSON data. If a circular reference is present, the string ‘Circular’ is added instead.
%o	Adds the string representation of an object. Note that it does not contain non-enumerable characteristics of the object.
%O	Adds the string representation of an object. Note that it will contain all characteristics of the object, including non-enumerable ones.
%c	Will parse basic CSS from the substitution subject like `color: red` into ANSI color codes. These codes will then be placed where the `%c` specifier is. Supported CSS properties are `color`, `background-color`, `font-weight`, `font-style`, `text-decoration`, `text-decoration-color`, and `text-decoration-line`. Unsupported CSS properties are ignored. An empty `%c` CSS string substitution will become an ANSI style reset. If color is disabled, `%c` is ignored.
%%	Used to add the % sign.

Benchmark

See benchmark

Supported Node.js Versions

Libraries in this ecosystem make the best effort to track Node.js’ release schedule. Here’s a post on why we think this is important.

Contributing

If you would like to help take a look at the list of issues and check our Contributing guild.

Note: please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.