Add tests

Author: reidmorrison

lib/active_record_replica/active_record_replica.rb

@@ -47,7 +47,7 @@ def self.read_from_primary(&block)
   # Then use this method and supply block to read from the replica database
   # Only applies to calls made within the current thread
   def self.read_from_replica(&block)
-    thread_variable_yield(:active_record_replica, nil, &block)
+    thread_variable_yield(:active_record_replica, :replica, &block)
   end
 
   # When only reading from a replica it is important to prevent entering any into
@@ -66,12 +66,19 @@ def self.skip_transactions
 
   # Whether this thread is currently forcing all reads to go against the primary database
   def self.read_from_primary?
-    !@read_from_replica || thread_variable_equals(:active_record_replica, :primary)
+    !read_from_replica?
   end
 
   # Whether this thread is currently forcing all reads to go against the replica database
   def self.read_from_replica?
-    @read_from_replica && thread_variable_equals(:active_record_replica, nil)
+    case Thread.current.thread_variable_get(:active_record_replica)
+    when :primary
+      false
+    when :replica
+      true
+    else
+      @read_from_replica
+    end
   end
 
   # Force all subsequent reads in this process to read from the primary database.

test/active_record_replica_test.rb

@@ -12,13 +12,14 @@
 #
 # The tests verify that reads going to the replica database do not find data written to the primary.
 class ActiveRecordReplicaTest < Minitest::Test
-  describe "the active_record_replica gem" do
+  describe ActiveRecordReplica do
     let(:user_name) { "Joe Bloggs" }
     let(:address) { "Somewhere" }
     let(:user) { User.new(name: user_name, address: address) }
 
     before do
       ActiveRecordReplica.ignore_transactions = false
+      ActiveRecordReplica.read_from_replica!
       User.delete_all
     end
 
@@ -95,5 +96,65 @@ class ActiveRecordReplicaTest < Minitest::Test
         assert_equal 1, User.where(name: user_name, address: address).count
       end
     end
+
+    describe ".read_from_replica?" do
+      it "is true when global replica flag is set" do
+        ActiveRecordReplica.read_from_replica!
+        assert ActiveRecordReplica.read_from_replica?
+      end
+
+      it "is false when reading from replica" do
+        ActiveRecordReplica.read_from_primary!
+        refute ActiveRecordReplica.read_from_replica?
+      end
+    end
+
+    describe ".read_from_primary?" do
+      it "is true when global primary flag is set" do
+        ActiveRecordReplica.read_from_primary!
+        assert ActiveRecordReplica.read_from_primary?
+      end
+
+      it "is false when reading from replica" do
+        ActiveRecordReplica.read_from_replica!
+        refute ActiveRecordReplica.read_from_primary?
+      end
+    end
+
+    describe ".read_from_replica" do
+      it "works with global replica flag" do
+        ActiveRecordReplica.read_from_replica!
+        ActiveRecordReplica.read_from_replica do
+          assert ActiveRecordReplica.read_from_replica?
+          refute ActiveRecordReplica.read_from_primary?
+        end
+      end
+
+      it "overwrites global replica flag" do
+        ActiveRecordReplica.read_from_primary!
+        ActiveRecordReplica.read_from_replica do
+          assert ActiveRecordReplica.read_from_replica?
+          refute ActiveRecordReplica.read_from_primary?
+        end
+      end
+    end
+
+    describe ".read_from_primary" do
+      it "works with global replica flag" do
+        ActiveRecordReplica.read_from_primary!
+        ActiveRecordReplica.read_from_primary do
+          assert ActiveRecordReplica.read_from_primary?
+          refute ActiveRecordReplica.read_from_replica?
+        end
+      end
+
+      it "overwrites global replica flag" do
+        ActiveRecordReplica.read_from_replica!
+        ActiveRecordReplica.read_from_primary do
+          assert ActiveRecordReplica.read_from_primary?
+          refute ActiveRecordReplica.read_from_replica?
+        end
+      end
+    end
   end
 end