☑️ Refining globbed_tail_locations for S3

Prior to this commit, we didn't have a spec for the S3 behavior.  We now
have a test for an S3 Faux Bucket.

Related to:

- https://github.com/scientist-softserv/adventist-dl/issues/330
- scientist-softserv/iiif_print#220

lib/derivative_rodeo/storage_locations/base_location.rb

@@ -208,16 +208,16 @@ def derived_file_from(template:)
 
       ##
       # When you have a known location and want to check for files that are within that location,
-      # use the #globbed_tail_locations method.  In the case of {Generators::PdfSplitGenerator} we
+      # use the {#globbed_tail_locations} method.  In the case of {Generators::PdfSplitGenerator} we
       # need to know the path to the all of the image files we "split" off of the given PDF.
       #
       # We can use the :file_path as the prefix the given :tail_glob as the suffix for a "fully
       # qualified" Dir.glob type search.
       #
       # @param tail_glob [String]
       #
-      # @return [StorageLocations::BaseLocation] when there is one or more files at the location
-      # @return [NilClass] when there are no files
+      # @return [Enumerable<StorageLocations::BaseLocation>] the locations of the files; an empty
+      #         array when there are none.
       def globbed_tail_locations(tail_glob:)
         raise NotImplementedError, "#{self.class}#globbed_locations"
       end

lib/derivative_rodeo/storage_locations/s3_location.rb

@@ -66,6 +66,8 @@ def exist?
       #
       # @note S3 allows searching on a prefix but does not allow for "wildcard" searches.  We can
       #       use the components of the file_path to fake that behavior.
+      #
+      # @see Generators::PdfSplitGenerator#image_file_basename_template
       def globbed_tail_locations(tail_glob:)
         # file_path = "s3://blah/1234/hello-world/pages/*.tiff"
         #
@@ -75,11 +77,19 @@ def globbed_tail_locations(tail_glob:)
         # and miscolate two PDFs.
         #
         # file_path = "s3://blah/1234/hello-world/hello-world.pdf
-        # TODO: Should file_path be file_dir?
-        globname = File.join(file_path, tail_glob)
+        globname = File.join(file_dir, tail_glob)
         regexp = %r{#{File.extname(globname)}$}
+
+        # NOTE: We're making some informed guesses, needing to include the fully qualified template
+        # based on both the key of the item in the bucket as well as the bucket's host.
+        uri = URI.parse(file_uri)
+        scheme_and_host = "#{uri.scheme}://#{uri.host}"
+
         bucket.objects(prefix: File.dirname(globname)).flat_map do |object|
-          derived_file_from(object.key) if object.key.match(regexp)
+          if object.key.match(regexp)
+            template = File.join(scheme_and_host, object.key)
+            derived_file_from(template: template)
+          end
         end
       end
 

spec/derivative_rodeo/storage_locations/s3_location_spec.rb

@@ -10,6 +10,7 @@
   before do
     # Let's use a FakeBucket instead!
     subject.use_actual_s3_bucket = false
+
     DerivativeRodeo.config do |config|
       config.aws_s3_bucket = 'fake-bucket'
       config.aws_s3_access_key_id = "FAKEFAKEFAKE"
@@ -66,11 +67,22 @@
 
   describe '#globbed_tail_locations' do
     it 'searched the bucket' do
-      basename_ish = short_path.split(".").first
-      key = File.join(basename_ish, File.basename(__FILE__))
+      # Because we instantiated the subject as a location to the :file_path (e.g. let(:file_path))
+      # we are encoding where things are relative to this file.  In other words, this logic is
+      # mirroring the generator logic that says where we're writing derivatives relative to their
+      # original file/input file.
+      bucket_dir = "files/#{File.basename(file_path, '.tiff')}"
+
+      basename = File.basename(__FILE__)
+      key = File.join(bucket_dir, "pages", basename)
       subject.bucket.object(key).upload_file(__FILE__)
 
-      subject.globbed_tail_locations(tail_glob: "*.rb")
+      non_matching_key = File.join(bucket_dir, "missing", basename)
+      subject.bucket.object(non_matching_key).upload_file(__FILE__)
+
+      locations = subject.globbed_tail_locations(tail_glob: "ocr_color/pages/*.rb")
+
+      expect(locations.size).to eq(1)
     end
   end
 end

spec/spec_helper.rb

@@ -36,7 +36,7 @@
 # of increasing the boot-up time by auto-requiring all files in the support
 # directory. Alternatively, in the individual `*_spec.rb` files, manually
 # require only the support files necessary.
-Dir.glob(File.expand_path("../lib/spec/support/**/*.rb", __dir__)).each { |f| require f }
+Dir.glob(File.expand_path("../lib/spec_support/**/*.rb", __dir__)).each { |f| require f }
 Dir.glob(File.expand_path('./support/**/*.rb', __dir__)).each { |f| require f }
 
 RSpec.configure do |config|