string-sameness#

Generate a score that represents how closely the same two strings are. The comparison function uses an average of:

• Dice's Coefficient
• Cosine Similarity
• Levenshtein Distance

weighted by the length of the content being compared (more weight for longer content).

The sameness is then given a score of 0 to 100.

• 0 => Totally unique pieces of content
• 100 => Identical content

Install/Usage#

npm install @foxxmd/string-sameness

import compare from '@foxxmd/string-sameness';

const result =  compare('This is one sentence', 'This is another sentence');
console.log(result);
// {
//     "scores": {
//         "dice": 66.66,
//         "cosine": 75,
//         "leven": 79.16
//      },
//     "highScore": 73.61,
//     "highScoreWeighted": 83.58
//  }

Normalization#

A third argument may be passed to compare to provide a list of functions to apply to the strings to compare. When not explicitly provided a default set of functions is applied to normalize the strings (to remove trivial differences):

• convert to lowercase
• trim (remove whitespace at beginning/end)
• remove non-alphanumeric characters (punctuation and newlines)
• replace any instances of 2 or more consecutive whitespace with 1 whitespace

This default set of functions is exported as defaultStrCompareTransformFuncs.

Example of supplying your own transform functions:

import compare, {defaultStrCompareTransformFuncs} from '@foxxmd/string-sameness';

const myFuncs = [
    ...defaultStrCompareTransformFuncs,
    // replace all vowels with the letter e
    (str) => str.replace(/[aeiou]/ig, 'e')
]

const result =  compare('This is one sentence', 'This is another sentence', myFuncs);