Awesome
yaml-types
Additional useful types for yaml
.
Installation and Usage
npm install yaml yaml-types
Each type (a.k.a. "tag") is available as a named export of 'yaml-types'
.
These may then be used as custom tags:
import { parse } from 'yaml'
import { regexp } from 'yaml-types'
const re = parse('!re /fo./g', { customTags: [regexp] })
'foxbarfoo'.match(re) // [ 'fox', 'foo' ]
Available Types
bigint
(!bigint
) - JavaScript BigInt values. Note: in order to use this effectively, a function must be provided ascustomTags
in order to prepend thebigint
tag, or else the built-in!!int
tags will take priority. See bigint.test.ts for examples.binary
(!!binary
) - JavaScript Uint8Array, one of the YAML 1.1 tagsclassTag
(!class
) - JavaScript Class valueserror
(!error
) - JavaScript Error objectsfunctionTag
(!function
) - JavaScript Function values (will also be used to stringify Class values, unless theclassTag
tag is loaded ahead offunctionTag
)nullobject
(!nullobject
) - Object with anull
prototypeomap
(!!omap
) - JavaScript Map, one of the YAML 1.1 tagspairs
(!!pairs
) - Ordered sequence of key-value pairs, one of the YAML 1.1 tagsregexp
(!re
) - RegExp values, using their default/foo/flags
string representation.set
(!!set
) - JavaScript Set, one of the YAML 1.1 tagssharedSymbol
(!symbol/shared
) - Shared Symbols, i.e. ones created withSymbol.for()
symbol
(!symbol
) - Unique Symbolstimestamp
(!!timestamp
) - JavaScript Date, one of the YAML 1.1 tags
The function and class values created by parsing !function
and
!class
tags will not actually replicate running code, but
rather no-op function/class values with matching name and
toString
properties.
Customising Tag Names
To use one of the types with a different tag identifier, set its tag
value accordingly.
For example, to extend the default tag namespace with !!js/symbol
instead of using a local !symbol
tag for Symbol values:
import { stringify } from 'yaml'
import { symbol } from 'yaml-types'
const mysymbol = { ...symbol, tag: 'tag:yaml.org,2002:js/symbol' }
stringify(Symbol('foo'), { customTags: [mysymbol] })
!!js/symbol foo
To use a named tag handle like !js!symbol
, a few more steps are required:
import { Document } from 'yaml'
import { symbol } from 'yaml-types'
const mysymbol = { ...symbol, tag: 'tag:js:symbol' }
const doc = new Document(Symbol('foo'), { customTags: [mysymbol] })
doc.directives.tags['!js!'] = 'tag:js:'
doc.toString()
%TAG !js! tag:js:
---
!js!symbol foo
Contributing
Additions to this library are very welcome!
Many data types are useful beyond any single project,
and while the core yaml
library is mostly limited to the YAML spec,
no such restriction applies here.
The source code is written in TypeScript, and the tests use Node-Tap. When submitting a PR for a new type, tests and documentation are required, as well as satisfying Prettier.