Twitch API Rules

extends: spectral:oas
rules:

  # Twitch API conventions: all summaries must use Title Case and include the "Twitch" prefix
  twitch-summary-title-case:
    description: Operation summaries must use Title Case
    message: "Summary '{{value}}' must use Title Case"
    given: "$.paths[*][*].summary"
    severity: warn
    then:
      function: pattern
      functionOptions:
        match: "^[A-Z][a-zA-Z0-9 ]+$"

  twitch-summary-provider-prefix:
    description: Operation summaries should be prefixed with the API product name (e.g. "Twitch")
    message: "Summary '{{value}}' should start with a provider or product prefix"
    given: "$.paths[*][*].summary"
    severity: hint
    then:
      function: pattern
      functionOptions:
        match: "^(Twitch|IGDB)"

  # Twitch requires Client-Id header on all authenticated operations
  twitch-requires-client-id-parameter:
    description: Twitch operations should reference the clientId parameter
    message: "Twitch operations should reference the #/components/parameters/clientId parameter"
    given: "$.paths[*][get,post,patch,put,delete].parameters[*]"
    severity: hint
    then:
      function: schema
      functionOptions:
        schema:
          type: object
          properties:
            $ref:
              type: string

  # OAuth2 security should be defined
  twitch-security-defined:
    description: All operations should declare security requirements
    message: "Operation '{{path}}' is missing security declaration"
    given: "$.paths[*][get,post,patch,put,delete]"
    severity: warn
    then:
      field: security
      function: truthy

  # Twitch uses bearer/app access tokens; no operation should use basic auth
  twitch-no-basic-auth:
    description: Twitch does not use HTTP Basic authentication
    message: "Basic authentication is not used in the Twitch API"
    given: "$.components.securitySchemes[*]"
    severity: error
    then:
      function: schema
      functionOptions:
        schema:
          not:
            properties:
              scheme:
                const: basic

  # Operation IDs must use camelCase
  twitch-operation-id-camel-case:
    description: Operation IDs must use camelCase
    message: "OperationId '{{value}}' must use camelCase"
    given: "$.paths[*][*].operationId"
    severity: warn
    then:
      function: pattern
      functionOptions:
        match: "^[a-z][a-zA-Z0-9]+$"

  # Tags must use Title Case
  twitch-tags-title-case:
    description: Tags must use Title Case
    message: "Tag '{{value}}' must use Title Case"
    given: "$.tags[*].name"
    severity: warn
    then:
      function: pattern
      functionOptions:
        match: "^[A-Z][a-zA-Z0-9 ]+$"

  # Responses must define at least a 200 or 201
  twitch-success-response-defined:
    description: Operations must define a success response
    message: "Operation must define a 200, 201, or 204 response"
    given: "$.paths[*][get,post,patch,put,delete].responses"
    severity: error
    then:
      function: schema
      functionOptions:
        schema:
          type: object
          anyOf:
            - required: ["200"]
            - required: ["201"]
            - required: ["204"]

  # All paths must be kebab-case
  twitch-paths-kebab-case:
    description: Path segments must use snake_case or kebab-case (Twitch uses snake_case)
    message: "Path '{{path}}' should use lowercase letters with underscores"
    given: "$.paths"
    severity: hint
    then:
      function: pattern
      functionOptions:
        match: "^(/[a-z][a-z0-9_/{}]*)+$"

  # Pagination parameters should follow Twitch conventions
  twitch-pagination-first-parameter:
    description: Collection GET endpoints should support pagination via 'first' and 'after' parameters
    message: "Collection endpoints should support 'first' and 'after' cursor pagination"
    given: "$.paths[*][get]"
    severity: hint
    then:
      function: schema
      functionOptions:
        schema:
          type: object