add support for aliases in s3 credentials YAML (kreeti#23)

lib/paperclip/storage/s3.rb

@@ -427,9 +427,9 @@ def copy_to_local_file(style, local_dest_path)
       def find_credentials(creds)
         case creds
         when File
-          YAML::safe_load(ERB.new(File.read(creds.path)).result)
+          YAML::safe_load(ERB.new(File.read(creds.path)).result, [], [], true)
         when String, Pathname
-          YAML::safe_load(ERB.new(File.read(creds)).result)
+          YAML::safe_load(ERB.new(File.read(creds)).result, [], [], true)
         when Hash
           creds
         when NilClass

spec/paperclip/storage/s3_spec.rb

@@ -1439,6 +1439,32 @@ class DummyCredentialProvider; end
     end
   end
 
+  context "with S3 credentials supplied as Pathname and aliases being set" do
+    before do
+      ENV["S3_KEY"]    = "pathname_key"
+      ENV["S3_BUCKET"] = "pathname_bucket"
+      ENV["S3_SECRET"] = "pathname_secret"
+
+      rails_env("test") do
+        rebuild_model aws2_add_region.merge storage: :s3,
+                                            s3_credentials: Pathname.new(fixture_file("aws_s3.yml"))
+
+        Dummy.delete_all
+        @dummy = Dummy.new
+      end
+    end
+
+    it "parses the credentials" do
+      assert_equal "pathname_bucket", @dummy.avatar.bucket_name
+
+      assert_equal "pathname_key",
+                   @dummy.avatar.s3_bucket.client.config.access_key_id
+
+      assert_equal "pathname_secret",
+                   @dummy.avatar.s3_bucket.client.config.secret_access_key
+    end
+  end
+
   context "with S3 credentials in a YAML file" do
     before do
       ENV["S3_KEY"]    = "env_key"
@@ -1466,6 +1492,33 @@ class DummyCredentialProvider; end
     end
   end
 
+  context "with S3 credentials in a YAML file and aliases being set" do
+    before do
+      ENV["S3_KEY"]    = "env_key"
+      ENV["S3_BUCKET"] = "env_bucket"
+      ENV["S3_SECRET"] = "env_secret"
+
+      rails_env("test") do
+        rebuild_model aws2_add_region.merge storage: :s3,
+                                            s3_credentials: File.new(fixture_file("aws_s3.yml"))
+
+        Dummy.delete_all
+
+        @dummy = Dummy.new
+      end
+    end
+
+    it "runs the file through ERB" do
+      assert_equal "env_bucket", @dummy.avatar.bucket_name
+
+      assert_equal "env_key",
+                   @dummy.avatar.s3_bucket.client.config.access_key_id
+
+      assert_equal "env_secret",
+                   @dummy.avatar.s3_bucket.client.config.secret_access_key
+    end
+  end
+
   context "S3 Permissions" do
     context "defaults to :public_read" do
       before do

spec/support/fixtures/aws_s3.yml

@@ -0,0 +1,13 @@
+default: &default
+  acl: public-read
+development:
+  <<: *default
+  key: 54321
+production:
+  <<: *default
+  key: 12345
+test:
+  <<: *default
+  bucket: <%= ENV['S3_BUCKET'] %>
+  access_key_id: <%= ENV['S3_KEY'] %>
+  secret_access_key: <%= ENV['S3_SECRET'] %>