Class: Console1984::CommandValidator

Inherits:
Object
  • Object
show all
Includes:
Freezeable
Defined in:
lib/console1984/command_validator.rb

Overview

Validates console commands.

This performs an static analysis of console commands. The analysis is meant to happen before commands are executed, so that they can prevent the execution if needed.

The validation itself happens as a chain of validation objects. The system will invoke each validation in order. Validations will raise an error if the validation fails (typically a Console1984::Errors::ForbiddenCommandAttempted or Console1984::Errors::SuspiciousCommands).

Internally, validations will receive a Console1984::CommandValidator::ParsedCommand object. This exposes parsed constructs in addition to the raw strings so that validations can use those.

There is a convenience method .from_config that lets you instantiate a validation setup from a config hash (e.g to customize validations via YAML).

See config/command_protections.yml and the validations in lib/console1984/command_validator.

Defined Under Namespace

Classes: ForbiddenConstantReferenceValidation, ForbiddenReopeningValidation, ParsedCommand, SuspiciousTermsValidation

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Freezeable

freeze_all, included

Constructor Details

#initialize ⇒ CommandValidator

Returns a new instance of CommandValidator.



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# File 'lib/console1984/command_validator.rb', line 20

def initialize
  @validations_by_name = HashWithIndifferentAccess.new
end

Class Method Details

.from_config(config) ⇒ Object

Instantiates a command validator that will configure the validations based on the config passed.

For each key in config, it will derive the class Console1984::CommandValidator::#keykey.camelizeValidation and will instantiate the validation passed the values as params.

For example for this config:

{ forbidden_reopening: [ActiveRecord, Console1984] }

It will instantiate Console1984::CommandValidator::ForbiddenReopeningValidation passing [“ActiveRecord”, “Console1984”] in the constructor.

# See config/command_protections.yml as an example.



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# File 'lib/console1984/command_validator.rb', line 38

def from_config(config)
  Console1984::CommandValidator.new.tap do |validator|
    config.each do |validator_name, validator_config|
      validator_class = "Console1984::CommandValidator::#{validator_name.to_s.camelize}Validation".constantize
      validator_config.try(:symbolize_keys!)
      validator.add_validation validator_name, validator_class.new(validator_config)
    end
  end
end

Instance Method Details

#add_validation(name, validation) ⇒ Object

Adds a validation to the chain indexed by the provided name

Validations are executed in the order they are added.



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# File 'lib/console1984/command_validator.rb', line 52

def add_validation(name, validation)
  validations_by_name[name] = validation
end

#validate(command) ⇒ Object

Executes the chain of validations passing a parsed command created with the command string passed by parameter.

The validations are executed in the order they were added. If one validation raises an error, the error will raise and the rest of validations won’t get checked.



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# File 'lib/console1984/command_validator.rb', line 61

def validate(command)
  parsed_command = ParsedCommand.new(command)

  validations_by_name.values.each do |validation|
    validation.validate(parsed_command)
  end
end