Re-Frame Multi-Line Text

This is a tiny JavaScript function for the Browser and Node.js to re-frame a multi-line text by stripping unnecessary extra indentation, strip trailing whitespace characters, strip unecessary leading and trailing blank lines and then optionally add back again some indentation and leading and trailing blank lines. This function allows you to re-frame a piece of multi-line text and is especially intended to be used with ES2015 multi-line string literals.

$ npm install textframe

const textframe = require("textframe")

/*  direct usage  */
textframe(`
    foo
        bar
    baz
        quux
`) --> "foo\n    bar\nbaz    quux\n"

/*  tagged template string usage  */
const bar = "bar"
textframe`
    foo
        ${bar}
    baz
        quux
` --> "foo\n    bar\nbaz    quux\n"

/*  factory usage  */
let tf = textframe.make({ indent: 4 })
console.log(tf("foo")) --> "    foo\n"
console.log(tf`foo`)   --> "    foo\n"

textframe(
    text: string,             /*  input text  */
    options?: {               /*  optional processing options  */
        tabsize:  number = 8, /*  expand TAB characters by 8 spaces  */
        indent:   number = 0, /*  (re-)indent by N spaces  */
        leading:  number = 0, /*  (re-)add N leading blank lines  */
        trailing: number = 0  /*  (re-)add N trailing blank lines  */
    }
}): string                    /*  output text  */

Copyright (c) 2017-2024 Dr. Ralf S. Engelschall (http://engelschall.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.