Class: GovukSchemas::RandomExample

Inherits:
Object
  • Object
show all
Defined in:
lib/govuk_schemas/random_example.rb

Overview

Generate random content based on a schema.

Limitations

  • The gem doesn't support patternProperties yet. On GOV.UK we use this in the expanded frontend links.
  • It's complicated to generate random data for oneOf properties. According to the JSON Schema spec a oneOf schema is only valid if the data is valid against only one of the clauses. To do this properly, we'd have to make sure that the data generated below doesn't validate against the other schemas properties.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema:, seed: nil) ⇒ GovukSchemas::RandomExample

Returns a new GovukSchemas::RandomExample object.

For example:

schema = GovukSchemas::Schema.find(frontend_schema: "detailed_guide")
GovukSchemas::RandomExample.new(schema: schema).payload

Example with seed (for consistent results):

schema = GovukSchemas::Schema.find(frontend_schema: "detailed_guide")
GovukSchemas::RandomExample.new(schema: schema, seed: 777).payload
GovukSchemas::RandomExample.new(schema: schema, seed: 777).payload # returns same as above



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# File 'lib/govuk_schemas/random_example.rb', line 34

def initialize(schema:, seed: nil)
  @schema = schema
  @random_generator = RandomSchemaGenerator.new(schema: schema, seed: seed)
end

Class Method Details

.for_schema(schema_key_value, &block) ⇒ GovukSchemas::RandomExample

Returns a new GovukSchemas::RandomExample object.

Example without block:

 GovukSchemas::RandomExample.for_schema(frontend_schema: "detailed_guide")
 # => {"base_path"=>"/e42dd28e", "title"=>"dolor est...", "publishing_app"=>"elit"...}

Example with block:

 GovukSchemas::RandomExample.for_schema(frontend_schema: "detailed_guide") do |payload|
   payload.merge('base_path' => "Test base path")
 end
 # => {"base_path"=>"Test base path", "title"=>"dolor est...", "publishing_app"=>"elit"...}



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# File 'lib/govuk_schemas/random_example.rb', line 59

def self.for_schema(schema_key_value, &block)
  schema = GovukSchemas::Schema.find(schema_key_value)
  GovukSchemas::RandomExample.new(schema: schema).payload(&block)
end

Instance Method Details

#payload ⇒ Hash

Return a content item merged with a hash and with the excluded fields removed. If the resulting content item isn't valid against the schema an error will be raised.

Example without block:

 generator.payload
 # => {"base_path"=>"/e42dd28e", "title"=>"dolor est...", "publishing_app"=>"elit"...}

Example with block:

 generator.payload do |payload|
   payload.merge('base_path' => "Test base path")
 end
 # => {"base_path"=>"Test base path", "title"=>"dolor est...", "publishing_app"=>"elit"...}

Raises:

  • (GovukSchemas::InvalidContentGenerated) 


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# File 'lib/govuk_schemas/random_example.rb', line 83

def payload
  payload = @random_generator.payload
  # ensure the base payload is valid
  errors = validation_errors_for(payload)
  raise InvalidContentGenerated, error_message(payload, errors) if errors.any?

  if block_given?
    payload = yield(payload)
    # check the payload again after customisation
    errors = validation_errors_for(payload)
    raise InvalidContentGenerated, error_message(payload, errors, customised: true) if errors.any?
  end

  payload
end