kuvio
Version:
Create string patterns and derive things from them, such as regexes
69 lines (53 loc) • 2.82 kB
Markdown
# kuvio
[](https://app.codacy.com/gh/skeate/kuvio/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
[](https://codecov.io/github/skeate/kuvio)
[](https://libraries.io/npm/kuvio)
[](https://bundlephobia.com/package/kuvio)
[](https://www.npmjs.com/package/kuvio)
`kuvio` is a tool to construct composable string patterns, from which you can
derive things like regular expressions or [fast-check][] `Arbitrary`s. As of
v1.4.0, it requires no dependencies.
`kuvio` is specifically for string-like patterns. If you want to extend this
concept to more complicated data types, check out [schemata-ts][]! `kuvio` was
originally developed as part of `schemata-ts` but was extracted as it seems
useful independently.
## Usage
`kuvio` comes with several useful patterns built-in, but you can also create
your own.
```typescript
import * as k from 'kuvio';
// Use built-in patterns
const creditCardRegex = k.regexFromPattern(k.patterns.creditCard);
// Create your own patterns.
const areaCode = k.exactly(3)(k.digit)
const exchangeCode = k.exactly(3)(k.digit)
const lineNumber = k.exactly(4)(k.digit)
// Create pattern functions
const parenthesize = (p: k.Pattern) => k.subgroup(
k.sequence(k.char('('), p, k.char(')'))
)
// Compose patterns to make more complex patterns
const phoneNumberPattern = k.sequence(
parenthesize(areaCode),
k.char(' '),
k.subgroup(exchangeCode),
k.char('-'),
k.subgroup(lineNumber),
)
```
See the [patterns](src/patterns) directory for the built-in patterns, which can also be useful examples for creating your own.
#### Note regarding `fast-check` usage
Arbitraries are intended primarily for use in test code; in order to
help keep `fast-check` out of your production code, `kuvio` does not include
`fast-check` in the main export. If you want to use the `Arbitrary` functions,
you'll need to import them separately from `kuvio/arbitrary`.
`kuvio` also exports a version of the `Arbitrary` functions that take the
`fast-check` library as an argument, to prevent any possible accidental
inclusion of `fast-check` in production code. This _shouldn't_ be an issue, but
there are many bundlers and we cannot test them all. You can import these from
`kuvio/arbitrary-deferred`.
[fast-check]: https://github.com/dubzzz/fast-check
[schemata-ts]: https://github.com/jacob-alford/schemata-ts