fuzzyhighlight

FORKED FROM / BASED ON fuzzysearch by Nicolas Bevacqua

Tiny, fast, and dependency-less fuzzy search + highlighting in JavaScript

Fuzzy searching allows for flexibly matching a string with partial input, useful for filtering data very quickly based on lightweight user input.

Demo

Head here for a simple working demo.

Install

npm install --save fuzzyhighlight

or

yarn add fuzzyhighlight

Usage

You may import fuzzyhighlight as a whole, or its methods separately.

import * as fuzzyhighlight from 'fuzzyhighlight'
import {
  fuzzyHighlight,
  fuzzySearch,
  highlight,
  isFuzzyMatch
} from 'fuzzyhighlight'

Interfaces

interface Index {
  start: number,
  end: number
}

interface Result {
  isMatch: boolean,
  indexes: Index[],
  score: number
}

interface Options {
  caseSensitive?: boolean,
  tag?: string
}

isFuzzyMatch

isFuzzyMatch(needle: string, haystack: string|object, options?: Options) : boolean

Returns true if needle matches haystack using a fuzzy-search algorithm. The method will return true only if each character in the needle can be found in the haystack and occurs after the preceding matches.

If the provided haystack is an object instead of a string, the method will return true if any of the object's values fuzzy-matches the needle.

Note that this program doesn't implement levenshtein distance, but rather a simplified version where there's no approximation.

Options

caseSensitive

Fuzzy-search is case insentitive by default, you can make it otherwise by providing options with { caseSensitive: true }.

Examples

isFuzzyMatch('twl', 'cartwheel') // true
isFuzzyMatch('art', 'cartwheel') // true
isFuzzyMatch('CaRt', 'cartwheel') // true
isFuzzyMatch('cw', 'cartwheel') // true
isFuzzyMatch('eE', 'cartwheel') // true
isFuzzyMatch('eeel', 'cartwheel') // false
isFuzzyMatch('dog', 'cartwheel') // false
isFuzzyMatch('CaRt', 'cartwheel', { caseSensitive: true }) // false
isFuzzyMatch('eE', 'cartwheel', { caseSensitive: true }) // false

isFuzzyMatch('car', { foo: 'cartwheel', bar: 'bar' }) // true
isFuzzyMatch('cwhl', { foo: 'foo', bar: 'cartwheel' }) // true
isFuzzyMatch('cWheEl', { foo: 'cartwheel', bar: 'cartwheel' }) // true
isFuzzyMatch('car', {}) // false
isFuzzyMatch('car', { foo: 'foo', bar: 'bar' }) // false
isFuzzyMatch('CarT', { foo: 'foo', bar: 'cartwheel' }, { caseSensitive: true }) // true

fuzzyHighlight

fuzzyHighlight(needle: string, haystack: string, options?: Options) : string

Returns haystack string with needle's matching characters wrapped in a <strong> tag by default.

Options

caseSensitive

Fuzzy-search is case insentitive by default, you can make it otherwise by providing options with { caseSensitive: true }.

tag

You can specify the tag you want to wrap the needle's matching characters with; otherwise, <strong> is used by default. Mind that it doesn't have to be a valid HTML tag.

Examples

fuzzyHighlight('car', 'cartwheel') // <strong>car</strong>twheel
fuzzyHighlight('twl', 'cartwheel') // car<strong>tw</strong>hee<strong>l</strong>
fuzzyHighlight('CaRe', 'cartwheel') // <strong>car</strong>wh<strong>e</strong>el
fuzzyHighlight('CaRe', 'cartwheel', { caseSensitive: true }) // cartwheel
fuzzyHighlight('cw', 'cartwheel', { tag: 'em' }) // <em>c</em>art<em>w</em>heel
fuzzyHighlight('ee', 'cartwheel', { tag: 'i' }) // cartwh<i>ee</i>l
fuzzyHighlight('wheel', 'cartwheel', { tag: 'foo' }) // cartwh<foo>ee</foo>l

fuzzySearch

fuzzySearch(needle: string, haystack: string, options?: Options) : Result

Returns an object of type Result, where isMatch is true if needle matches haystack using a fuzzy-search algorithm.

In turn, indexes contains an array of type Index, which represents the start and end indexes of the needle's characters matched in the haystack. The purpose of this array is mostly to be used by the highlight method.

Finally score is the length of the longest slice of consecutively matching characters of needle inside haystack (i.e. the maximum difference between its index pairs). The score is useful when matching a list of entries against the same needle -which is most probably everyone's use case-, because you can use it to sort the positive matches from best to worst score.

NOTE: The working demo implements this sorting behavior if you want to try it out.

Options

caseSensitive

Fuzzy-search is case insentitive by default, you can make it otherwise by providing options with { caseSensitive: true }.

Examples

fuzzySearch('twl', 'cartwheel')
// {
//   isMatch: true,
//   indexes: [{ start: 3, end: 5}, { start: 8, end: 9 }],
//   score: 2
// }
fuzzySearch('art', 'cartwheel')
// {
//   isMatch: true,
//   indexes: [{ start: 1, end: 4}],
//   score: 3
// }
fuzzySearch('cw', 'cartwheel')
// {
//   isMatch: true,
//   indexes: [{ start: 0, end: 1}, { start: 4, end: 5 }]
//   score: 1
// }
fuzzySearch('ee', 'cartwheel')
// {
//   isMatch: true,
//   indexes: [{ start: 6, end: 8}]
//   score: 2
// }
fuzzySearch('eeel', 'cartwheel')
// {
//   isMatch: false,
//   indexes: []
//   score: 0
// }
fuzzySearch('CaRt', 'cartwheel', { caseSensitive: true })
// {
//   isMatch: false,
//   indexes: []
//   score: 0
// }
fuzzySearch('dog', 'cartwheel')
// {
//   isMatch: false,
//   indexes: [],
//   score: 0
// }

highlight

highlight(label: string, indexes: Index[], tag: string = 'strong')

Returns label with its characters in-between indexes wrapped in the given tag. If tag is not specified, <strong> is used by default.

The indexes parameter should be of type Index[].

Examples

highlight('cartwheel', [{ start: 0, end: 3 }]) // <strong>car</strong>twheel
highlight('cartwheel', [{ start: 1, end: 4}]) // car<strong>tw</strong>hee<strong>l</strong>
highlight('cartwheel', [{ start: 0, end: 1}, { start: 4, end: 5 }], 'b') // <b>c</b>art<b>w</b>heel
highlight('cartwheel', [{ start: 6, end: 8}], 'i') // cartwh<i>ee</i>l

The current implementation uses the algorithm suggested by Mr. Aleph, a crazy russian compiler engineer working at V8.

License

MIT