chervil/spec/ast/identifier_spec.rb

module Chervil
  RSpec.describe AST::Identifier do
    it 'evaluates' do
      env = Env.new
      identifier = AST::Identifier.new("x")
      value = AST::Number.new(5.0)
      definition = AST::Definition.new(identifier, value)
      definition.evaluate(env)
      expect(identifier.evaluate(env)).to eq(5.0)
    end

    it 'returns an error for an unbound identifier' do
      env = Env.new
      identifier = AST::Identifier.new("x")
      expect(identifier.evaluate(env)).to eq(Error.new("unbound variable x"))
    end
  end
end