class GraphQL::Query::Variables

Read-only access to query variables, applying default values if needed.

def [](key) 

def [](key)
  @storage.fetch(key)
end

def get_graphql_value(ast_variable)

If it's still nil, raise an error if it's required.
- Then, fall back to the default value from the query string
- First, use the value provided at runtime
Find the right value for this variable: 
def get_graphql_value(ast_variable)
  variable_type = @schema.type_from_ast(ast_variable.type)
  variable_name = ast_variable.name
  default_value = ast_variable.default_value
  provided_value = @provided_variables[variable_name]
  validation_result = variable_type.validate_input(provided_value)
  if !validation_result.valid?
    raise GraphQL::Query::VariableValidationError.new(ast_variable, variable_type, provided_value, validation_result)
  elsif provided_value.nil?
    GraphQL::Query::LiteralInput.coerce(variable_type, default_value, {})
  else
    variable_type.coerce_input(provided_value)
  end
end

def initialize(schema, ast_variables, provided_variables) 

def initialize(schema, ast_variables, provided_variables)
  @schema = schema
  @provided_variables = provided_variables
  @storage = ast_variables.each_with_object({}) do |ast_variable, memo|
    variable_name = ast_variable.name
    memo[variable_name] = get_graphql_value(ast_variable)
  end
end