feat(functions): add unicodeRegExp option to schema core function

[mtso]

Fixes #2419.

Checklist

• Tests added / updated
• Docs added / updated

Does this PR introduce a breaking change?

• Yes
• No

Screenshots

Before:

After:

Added unicodeRegExp to core function docs

Additional context

Adds an option unicodeRegExp to the schema core function. Defaults to "false". When "true", uses the unicode flag "u" with "pattern" and "patternProperties" fields during schema validation; otherwise does not use the "u" flag when "false" or omitted.

The unicodeRegExp option is optional, and thus backwards compatible with the existing behavior of spectral's schema core function. When the option is omitted, the behavior is defaulted to "false".

The unicodeRegExp option is also added as an optional flag to oasSchema and oasExample oas functions. To preserve the existing behavior of the standard oas ruleset, unicodeRegExp: false has been explicitly added to the standard oas ruleset's duplicated-entry-in-enum, oas2-valid-schema-example, oas2-valid-media-example, oas3-valid-media-example and oas3-valid-schema-example rules.

Adding this option allows rulesets that use the schema core function to opt into using the unicode "u" flag when validating the "pattern" and "patternProperty" fields.

Adding this option to oasExample and oasSchema also allows rulesets that extend from spectral:oas to replace the oas3-valid-media-example and oas3-valid-schema-example rules with a version that opts into using unicode regular expressions. Doing so is currently a little involved, though, requiring re-specifying the given block of the rules as shown below. But it at least makes the option available to extending rulesets.

// functions/oasExample.js
import { default as oasExample } from '@stoplight/spectral-rulesets/dist/oas/functions/oasExample';

export default oasExample;

# spectral.yaml
extends: ['spectral:oas']

functions:
- 'oasExample'

rules:
  oas3-valid-schema-example:
    given:
      - $.components.schemas..[?(@property !== 'properties' && @ && (@ && @.example !== void 0 || @.default !== void 0) && (@.enum || @.type || @.format || @.$ref || @.properties || @.items))]
      - $..content..[?(@property !== 'properties' && @ && (@ && @.example !== void 0 || @.default !== void 0) && (@.enum || @.type || @.format || @.$ref || @.properties || @.items))]
      - $..headers..[?(@property !== 'properties' && @ && (@ && @.example !== void 0 || @.default !== void 0) && (@.enum || @.type || @.format || @.$ref || @.properties || @.items))]
      - $..parameters..[?(@property !== 'properties' && @ && (@ && @.example !== void 0 || @.default !== void 0) && (@.enum || @.type || @.format || @.$ref || @.properties || @.items))]
    then:
      function: oasExample
      functionOptions:
        schemaField: '$'
        oasVersion: 3
        type: 'schema'
        unicodeRegExp: true

  oas3-valid-media-example:
    given:
      - '$..content..[?(@ && @.schema && (@.example !== void 0 || @.examples))]'
      - '$..headers..[?(@ && @.schema && (@.example !== void 0 || @.examples))]'
      - '$..parameters..[?(@ && @.schema && (@.example !== void 0 || @.examples))]'
    then:
      function: oasExample
      functionOptions:
        schemaField: 'schema'
        oasVersion: 3
        type: 'media'
        unicodeRegExp: true

[mtso]

@mnaumanali94 / @frankkilcommins , when you get the chance, could you please take a look?