Class: Contrast::Agent::Patching::Policy::PolicyNode Abstract

Inherits:
Object
  • Object
show all
Includes:
Components::Scope::InstanceMethods
Defined in:
lib/contrast/agent/patching/policy/policy_node.rb

Overview

This class is abstract.

This class functions to translate our policy.json into an actionable Ruby object, allowing for dynamic patching over hardcoded patching.

Constant Summary collapse

JSON_METHOD_VISIBILITY = 
'method_visibility'
JSON_PROPERTIES = 
'properties'
JSON_METHOD_NAME = 
'method_name'
JSON_METHOD_SCOPE = 
'scope'
JSON_CLASS_NAME =

The keys used to read from policy.json to create the individual policy nodes. These are common across node types

'class_name'
JSON_INSTANCE_METHOD = 
'instance_method'

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Components::Scope::InstanceMethods

#contrast_enter_method_scopes!, #contrast_exit_method_scopes!, #with_app_scope, #with_contrast_scope, #with_deserialization_scope, #with_split_scope

Constructor Details

#initialize(policy_hash = {}) ⇒ PolicyNode

Returns a new instance of PolicyNode.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 25

def initialize policy_hash = {}
  @class_name = policy_hash[JSON_CLASS_NAME]
  @instance_method = policy_hash[JSON_INSTANCE_METHOD]
  @method_name = policy_hash[JSON_METHOD_NAME]
  @method_scope = policy_hash[JSON_METHOD_SCOPE]
  @method_visibility = policy_hash[JSON_METHOD_VISIBILITY]
  @properties = policy_hash[JSON_PROPERTIES]
  symbolize
end

Instance Attribute Details

#class_name ⇒ Object

Name of the class in which the method is being invoked.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 36

def class_name
  @class_name
end

#instance_method ⇒ Object

Check for instance method.

Returns:

  • true | false



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 40

def instance_method
  @instance_method
end

#method_name ⇒ Object

The symbol representation of the invoked method.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 42

def method_name
  @method_name
end

#method_scope ⇒ Object (readonly)

Scope of the method parsed from our JSON policy.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 48

def method_scope
  @method_scope
end

#method_visibility ⇒ Object

Visibility of the invoked method [Private, Public, Protected]



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 44

def method_visibility
  @method_visibility
end

#properties ⇒ Object (readonly)

Properties parsed from our JSON policy.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 46

def properties
  @properties
end

Instance Method Details

#feature ⇒ Object

Raises:

  • (NoMethodError) —

    This is being raised if any of the implementing subclasses does not have that method implemented, but is being called on.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 58

def feature
  raise(NoMethodError, 'specify the name of the feature for which this node patches')
end

#id ⇒ Object 



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 62

def id
  @_id ||= "#{ feature }:#{ node_class }:#{ class_name }#{ instance_method? ? '#' : '.' }#{ method_name }"
end

#instance_method? ⇒ Boolean

just turns this into a ruby-ism

Returns:

  • (Boolean) 


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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 94

def instance_method?
  instance_method
end

#node_class ⇒ Object

Raises:

  • (NoMethodError) —

    This is being raised if any of the implementing subclasses does not have that method implemented, but is being called on.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 52

def node_class
  raise(NoMethodError, 'specify the type of the feature for which this node patches')
end

#validate ⇒ Object

Don’t let nodes be created that will be missing things we need later on. Really, if they don’t have these things, they couldn’t have done their jobs anyway.

Raises:

  • (ArgumentError) —

    Validates if the created nodes have everything that we’ll need now or later on.



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# File 'lib/contrast/agent/patching/policy/policy_node.rb', line 71

def validate
  unless class_name
    raise(ArgumentError, "#{ node_class } #{ id } did not have a proper class name. Unable to create.")
  end
  unless method_name
    raise(ArgumentError, "#{ node_class } #{ id } did not have a proper method name. Unable to create.")
  end
  unless method_name.is_a?(Symbol)
    raise(ArgumentError, "#{ node_class } #{ id } has a non symbol @method_name value. Unable to create.")
  end

  unless method_visibility.is_a?(Symbol)
    raise(ArgumentError,
          "#{ node_class } #{ id } has a non symbol @method_visibility value. Unable to create.")
  end
  unless method_scope.nil? || Contrast::Agent::Scope.valid_scope?(method_scope)
    raise(ArgumentError, "#{ node_class } #{ id } requires an undefined scope. Unable to create.")
  end

  nil
end