From b0db5ff208c65202e00388455d7058d6cdbfa2c2 Mon Sep 17 00:00:00 2001
From: Pat Allan <pat@freelancing-gods.com>
Date: Mon, 5 Nov 2018 17:37:06 +1100
Subject: [PATCH] Rails 5.2 support (and dropping 4.1 support).
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All the instance variable wrangling has been kept for compatibility’s sake (given they’re in the specs).

Instead of hand-crafting dirty support, this commit makes use of Rails’ own approach, though it does differ slightly between versions.
---
 Appraisals                        |  8 +++---
 lib/vault/encrypted_model.rb      | 42 ++++++++++++-------------------
 spec/unit/encrypted_model_spec.rb |  7 +++---
 3 files changed, 23 insertions(+), 34 deletions(-)

diff --git a/Appraisals b/Appraisals
index 40267be3..609041a8 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,7 +1,3 @@
-appraise "rails-4.1" do
-  gem "rails", "~> 4.1.0"
-end if RUBY_VERSION.to_f < 2.4
-
 appraise "rails-4.2" do
   gem "rails", "~> 4.2.0"
 end
@@ -13,3 +9,7 @@ end
 appraise "rails-5.1" do
   gem "rails", "~> 5.1.0"
 end
+
+appraise "rails-5.2" do
+  gem "rails", "~> 5.2.0"
+end
diff --git a/lib/vault/encrypted_model.rb b/lib/vault/encrypted_model.rb
index f57cc548..f212c0ae 100644
--- a/lib/vault/encrypted_model.rb
+++ b/lib/vault/encrypted_model.rb
@@ -63,10 +63,13 @@ def vault_attribute(attribute, options = {})
           serializer.define_singleton_method(:decode, &options[:decode])
         end
 
+        self.attribute attribute.to_s, ActiveRecord::Type::Value.new,
+          default: nil
+
         # Getter
         define_method("#{attribute}") do
           self.__vault_load_attributes! unless @__vault_loaded
-          instance_variable_get("@#{attribute}")
+          super()
         end
 
         # Setter
@@ -79,6 +82,7 @@ def vault_attribute(attribute, options = {})
 
           attribute_will_change!("#{attribute}")
           instance_variable_set("@#{attribute}", value)
+          super(value)
 
           # Return the value to be consistent with other AR methods.
           value
@@ -86,27 +90,7 @@ def vault_attribute(attribute, options = {})
 
         # Checker
         define_method("#{attribute}?") do
-          self.__vault_load_attributes! unless @__vault_loaded
-          instance_variable_get("@#{attribute}").present?
-        end
-
-        # Dirty method
-        define_method("#{attribute}_change") do
-          changes["#{attribute}"]
-        end
-
-        # Dirty method
-        define_method("#{attribute}_changed?") do
-          changed.include?("#{attribute}")
-        end
-
-        # Dirty method
-        define_method("#{attribute}_was") do
-          if changes["#{attribute}"]
-            changes["#{attribute}"][0]
-          else
-            public_send("#{attribute}")
-          end
+          public_send(attribute).present?
         end
 
         # Make a note of this attribute so we can use it in the future (maybe).
@@ -212,7 +196,7 @@ def __vault_load_attribute!(attribute, options)
 
         # If the user provided a value for the attribute, do not try to load
         # it from Vault
-        if instance_variable_get("@#{attribute}")
+        if attributes[attribute.to_s]
           return
         end
 
@@ -232,6 +216,7 @@ def __vault_load_attribute!(attribute, options)
 
         # Write the virtual attribute with the plaintext value
         instance_variable_set("@#{attribute}", plaintext)
+        @attributes.write_from_database attribute.to_s, plaintext
       end
 
       # Encrypt all the attributes using Vault and set the encrypted values back
@@ -267,12 +252,16 @@ def __vault_persist_attribute!(attribute, options)
 
         # Only persist changed attributes to minimize requests - this helps
         # minimize the number of requests to Vault.
-        if !changed.include?("#{attribute}")
-          return
+        if ActiveRecord.gem_version >= Gem::Version.new("5.2")
+          return unless previous_changes_include?(attribute)
+        elsif ActiveRecord.gem_version >= Gem::Version.new("5.1")
+          return unless saved_change_to_attribute?(attribute.to_s)
+        else
+          return unless attribute_changed?(attribute)
         end
 
         # Get the current value of the plaintext attribute
-        plaintext = instance_variable_get("@#{attribute}")
+        plaintext = attributes[attribute.to_s]
 
         # Apply the serialize to the plaintext value, if one exists
         if serializer
@@ -319,6 +308,7 @@ def reload(*)
           # from Vault
           self.class.__vault_attributes.each do |attribute, _|
             self.instance_variable_set("@#{attribute}", nil)
+            @attributes.write_from_database attribute.to_s, nil
           end
 
           self.__vault_initialize_attributes!
diff --git a/spec/unit/encrypted_model_spec.rb b/spec/unit/encrypted_model_spec.rb
index f3f1f3d8..ff326ff2 100644
--- a/spec/unit/encrypted_model_spec.rb
+++ b/spec/unit/encrypted_model_spec.rb
@@ -42,10 +42,9 @@
     end
 
     it "defines dirty attribute methods" do
-      klass.vault_attribute(:foo)
-      expect(klass.instance_methods).to include(:foo_change)
-      expect(klass.instance_methods).to include(:foo_changed?)
-      expect(klass.instance_methods).to include(:foo_was)
+      expect(Person.new).to respond_to(:ssn_change)
+      expect(Person.new).to respond_to(:ssn_changed?)
+      expect(Person.new).to respond_to(:ssn_was)
     end
   end
 end