porter_stemmer_nl_spec.ts

/*
Copyright (c) 2019, Hugo W.L. ter Doest

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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The above copyright notice and this permission notice shall be included in
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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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,
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THE SOFTWARE.
*/

'use strict'

import { PorterStemmerNl as stemmer } from 'lib/natural'
import rawObj from '../spec/test_data/snowball_nl.json'
const snowBallDict = rawObj as Record<string, string>
// const dutchSentences = require('spec/test_data/Volkskrant-20150205-Knot-geldpers-aanzetten-is-paardenmiddel-voor-half-procent-inflatie.json')
// const dutchStemResults = require('spec/test_data/dutchStemResults.json')

const DEBUG = false

describe('porter_stemmer_nl', function () {
  it('should perform stemming on a lot of words', function () {
    const errors = []

    Object.keys(snowBallDict).forEach(word => {
      const stemmed = stemmer.stem(word)
      const expectedStem = snowBallDict[word]
      if (stemmed !== snowBallDict[word]) {
        DEBUG && console.log('Error:', word, 'Expected:', expectedStem, 'Got:', stemmed)
        errors.push({
          word,
          expected: expectedStem,
          actual: stemmed
        })
      }
    })

    // The stemmer has an error count of 237 against the snowball list for nl that has 45669 entries
    expect(errors.length).toEqual(237)
  })

  // Commented out because hyphens are not processed correctly in the expected results
  /*
  it('should tokenize a piece of text', function () {
    dutchSentences.sentences.forEach((sentence, index) => {
      const result = stemmer.tokenizeAndStem(sentence, true)
      DEBUG && console.log(result)
      expect(result).toEqual(dutchStemResults.results[index])
    })
  })
  */

  /*
  it('should work with the attached notation', function() {
    stemmer.attach();
    expect("mogelijkheid".stem()).toEqual("mogelijk");
    expect("Knot: geldpers aanzetten is paardenmiddel voor half procent inflatie".tokenizeAndStem(true)).toEqual(
      [ 'knot', 'geldper', 'aanzet', 'is', 'paardenmiddel', 'vor', 'half', 'procent', 'inflatie' ]);
  });
  */
})