striff

Simple string diffing. Given two strings, striff will return an object noting which characters were added or removed, and at which indices.

Installation

Run npm install striff. Or stick in on a page via CDN.

Usage

Import it, pass a couple of strings, and do whatever you want with the results.

import striff from "striff";

const result = striff("string #1", "string #2");

// {
//   added: [
//     ...added characters
//   ],
//   removed: [
//     ...removed characters
//   ]
// }

Examples

Here's the kind of result you'll get with different types of diffing.

Strings w/ Characters Added

Input

const str1 = "abc";
const str2 = "abcde";

const result = striff(str1, str2);

Result

{
  added: [
    {
      value: "d",
      index: 3
    },
    {
      value: "e",
      index: 4
    }
  ],
  removed: []
}

Strings w/ Characters Removed

Input

const str1 = "abc";
const str2 = "a";

const result = striff(str1, str2);

Result

{
    added: [],
    removed: [
    {
      value: "b",
      index: 1
    },
    {
      value: "c",
      index: 2
    }
  ]
}

Strings w/ Duplicate Characters

Handling strings with duplicate, consecutive characters removed is a little weird. For strings whose characters were changed at the end, the indices will be grouped together at the end of the string.

Input

const str1 = "abbbc";
const str2 = "ab";

const result = striff(str1, str2);

Result

{
  added: [],
  removed: [
    {
      value: "b",
      index: 2
    },
    {
      value: "b",
      index: 3
    },
    {
      value: "c",
      index: 4
    }
  ]
}

For those whose whose characters were changed at the beginning, the indices will be grouped together at the beginning.

Input

const str1 = "abbbc";
const str2 = "bc";

const result = striff(str1, str2);

Result

{
  added: [].
  removed: [
    {
      value: "a",
      index: 0
    },
    {
      value: "b",
      index: 1
    },
    {
      value: "b",
      index: 2
    }
  ]
}

Feedback or Contributions

Make an issue or a pull request!