Declaratively define rules for string equivalence so you can focus on the differences that matter.
Equivalency lets you declaratively define rules for string equivalence.
Equivalency works in both Node and browsers back as far as IE 11 (full list of supported browsers).
const checker = require('equivalency');
const { Equivalency } = checker;
// Default rule is byte-equality.
checker.compare('a', 'a');
// { isEquivalent: true }
checker.compare('a', 'A');
// { isEquivalent: false }
// Specify which differences matter/don't matter.
checker.doesntMatter(Equivalency.CAPITALIZATION);
checker.compare('a', 'A');
// { isEquivalent: true }
checker.compare('Hot-dog', 'hotdog');
// { isEquivalent: false }
checker.doesntMatter(Equivalency.en.COMMON_PUNCTUATION);
checker.compare('Hot-dog', 'hotdog');
// { isEquivalent: true }
checker.compare('Go away, fly!', 'Go away; fly!');
// { isEquivalent: true }
checker.matters(',;');
checker.compare('Go away, fly!', 'Go away; fly!');
// { isEquivalent: false }
checker.compare('Go away, fly!', 'Go away; fly!',{giveReasons: true});
// { isEquivalent: false, reasons: [{name: ',;'}] }
// Return edit distance
const options = { calculateEditDistance: true };
checker.compare('show', 'shoe', options);
// { isEquivalent: false, editDistance: 1 }
const esChecker = new Equivalency();
esChecker.compare('adiós', 'adios');
// { isEquivalent: false }
const enChecker = new Equivalency();
enChecker.doesntMatter(Equivalency.ACCENTS);
enChecker.compare('adiós', 'adios');
// { isEquivalent: true }
// Root equivalency: normalizes Unicode, whitespace differences, and case.
const root = new Equivalency()
.doesntMatter(Equivalency.UNICODE_NORMALIZATION)
.doesntMatter(Equivalency.WHITESPACE_DIFFERENCES)
.doesntMatter(Equivalency.CAPITALIZATION)
// Diacritic-blind equivalency cloned from root equivalency.
const equivalencyForDiacriticWarning = root
.clone()
.doesntMatter(Equivalency.COMMON_DIACRITICS);
const isMatch = root.compare(
providedAnswer,
expectedAnswer
).isEquivalent;
const isMatchExceptForDiacritics = equivalencyForDiacriticWarning.compare(
providedAnswer,
expectedAnswer
).isEquivalent;
Equivalency Rules are not applied strictly in the order they are supplied. All map rules are applied, and only then are function rules applied. Therefore, FunctionRules can apply transformations on top of MapRule transformations, but MapRules cannot apply transformations on top of FunctionRules. These two rule types are also applied in fundamentally different ways. MapRules are collapsed into a single map which is then used to transform the comparison strings in a single operation. When two MapRules have conflicting mappings, the mappings in the rule further down the rule chain takes precedence. FunctionRules cascade such that transformation operations are performed individually one after another in the order given.
yarn test
BROWSER_STACK_ACCESS_KEY=<key> yarn run test:karma
See the release doc.