n1kk/shift-tab

Removes leading tabs from string template literals.

shift-tab

String template tag to manage indent in a multiline text block and some more. Use custom processors to create your own powerful loggers, stylers and formatters.

Works with both tabs and spaces. The first indent character that is encountered will become the indentation character, a mix won't work.

Usage

Install:

npm install shift-tab
yarn add shift-tab
pnpm add shift-tab

Import:

import shiftTab from "shift-tab";
// or it's shorter alias
import { $t } from "shift-tab"; // see all aliases at the bottom

Simple usage:

// some indented code
    // some indented code
        // ....
        if (error) {
            console.error($t`
                An error has occured:
                    code: ${error.code}
                    message: ${error.message}
            `);
        }

This will output following

An error has occured:
    code: ${error.code}
    message: ${error.message}

Adding preprocessors:

import chalkTemplate from "chalk-template";
import shiftTab, { untag } from "./dist/index.js";

const print = shiftTab({ process: [untag(chalkTemplate), console.log] });

Now we have a neat little logger that will output unindented, trimmed multiline text with colorization support

// ...
    if (error) {
        print`
            {red An error has occurred}:
              code: {blue ${error.code}}
              message: {yellowBright ${error.message}}
        `;
    }

That will print a trimmed and colored message:

API and Configuration

TypeScript signatures:

// to use as a template tag
function shiftTab(strings: TemplateStringsArray, ...variables: any[]): string;
// to use as a regualr function
function shiftTab(text: string): string;
// to use as a factory
function shiftTab(config: Options): TemplateTag; // retured function can be used as previous two

Aliases:

const $t = shiftTab;
const $tm = shiftTab({ indent: "smallest" });
const $tt = shiftTab({ trim: "lines" });
const $ttm = shiftTab({ trim: "lines", indent: "smallest" });

Configuration options

type Options = {
  indent?: "first" | "smallest" | "all" | number;
  trim?: "wrap" | "lines" | "none";
  process?: Processor[];
};

• indent: How to treat indentation of the lines, default "first"
  • "first": Find first indentation non-empty line and shift all text bu it's indentation
  • "smallest": Get the minimum indentation of all non empty lines and shift text by that amount
  • "all": Remove all indentation
  • number: a number if whitespace characters to decrease the indent to (or increase to)
• trim: How to treat leading and trailing empty lines, default "wrap"
  • "wrap": remove only wrap lines of multiline template tag (first and last), if first line is empty and last line is a whitespace
  • "lines": remove all leading and trailing epty and whitespace lines
  • "none": preserve all lines
• process: an array of methods to pipe the output through before returning, should accept string, return string value replaces text, other return types are ignored

Untag

Takes a template tag and return function that accepts string and return string

function untag(tag: TemplateTag): Processor;

type Processor = (input: string) => string | any;