TTO-214 Catalog should use the most recent redirects file instead of … (

#46)

* TTO-214 Catalog should use the most recent redirects file instead of failing when the redirects file for the current month doesn't exist
- Default behavior when `REDIRECT_FILE` is not set is to use this month's file and failing that, last month's.
- Move logic relating to default location and name of redirect files from Services to Redirects.

Gemfile.lock

@@ -38,6 +38,7 @@ GEM
     httpclient (2.8.3)
     httpx (0.23.3)
       http-2-next (>= 0.4.1)
+    jdbc-mysql (8.0.30)
     json (2.6.3)
     json (2.6.3-java)
     language_server-protocol (3.17.0.3)
@@ -52,11 +53,14 @@ GEM
       unf
     marc-fastxmlwriter (1.1.0)
       marc (~> 1.0)
+    marc-marc4j (1.0.0-java)
+      marc (~> 1)
     marc_alephsequential (2.0.0)
       marc (~> 1)
       yell (~> 2)
     match_map (3.0.0)
     method_source (1.0.0)
+    naconormalizer (1.0.1-java)
     nokogiri (1.16.2-arm64-darwin)
       racc (~> 1.4)
     nokogiri (1.16.2-java)
@@ -150,6 +154,9 @@ GEM
       nokogiri (~> 1.9)
       slop (~> 4.0)
       yell
+    traject-marc4j_reader (1.1.0-java)
+      marc (~> 1.0)
+      marc-marc4j (~> 1.0)
     traject_alephsequential_reader (1.1.2)
       marc (~> 1)
       marc_alephsequential (~> 2)
@@ -176,9 +183,11 @@ DEPENDENCIES
   http (~> 5.0)
   httpclient
   httpx
+  jdbc-mysql
   library_stdnums
   marc-fastxmlwriter (~> 1.1)
   match_map
+  naconormalizer
   pry
   rake (~> 13.0)
   rsolr
@@ -190,6 +199,7 @@ DEPENDENCIES
   standard
   thor
   traject (~> 3.0)
+  traject-marc4j_reader
   traject_alephsequential_reader
   traject_umich_format
   yell

lib/ht_traject/redirects.rb

@@ -11,6 +11,19 @@
 
 module HathiTrust
   class Redirects
+    def self.redirects_file_name(date: Date.today)
+      "redirects_#{date.strftime "%Y%m"}.txt.gz"
+    end
+
+    def self.default_redirects_file(directory: "/htapps/babel/hathifiles/catalog_redirects/redirects")
+      default_file = File.join(directory, redirects_file_name)
+      if !File.exist?(default_file)
+        # Fall back to previous month's (that's what the << method does) file
+        default_file = File.join(directory, redirects_file_name(date: Date.today << 1))
+      end
+      default_file
+    end
+
     def old_ids_for(id)
       redirects[id] || []
     end

lib/services.rb

@@ -64,10 +64,8 @@ def env_local_file
   end
 
   Services.register(:redirect_file) do
-    yyyymm = DateTime.now.strftime "%Y%m"
-    default_file = "/htapps/babel/hathifiles/catalog_redirects/redirects/redirects_#{yyyymm}.txt.gz"
     # Start migrating from redirect_file to REDIRECT_FILE on principle of least surprise
-    ENV["redirect_file"] || ENV["REDIRECT_FILE"] || default_file
+    ENV["redirect_file"] || ENV["REDIRECT_FILE"] || Redirects.default_redirects_file
   end
 
   Services.register(:db) do

spec/ht_traject/redirects_spec.rb

@@ -8,6 +8,37 @@
   let(:sample_old_cid) { "000004165" }
   let(:sample_new_cid) { "006215998" }
 
+  describe ".redirects_file_name" do
+    it "generates the appropriately dated redirects file" do
+      expect(described_class.redirects_file_name(date: Date.parse("2024-01-01")))
+        .to eq("redirects_202401.txt.gz")
+    end
+  end
+
+  describe ".default_redirects_file" do
+    context "with current month's file" do
+      it "uses the existing file" do
+        Dir.mktmpdir do |tmpdir|
+          current_file = File.join(tmpdir, described_class.redirects_file_name)
+          FileUtils.touch current_file
+          expect(described_class.default_redirects_file(directory: tmpdir))
+            .to eq(current_file)
+        end
+      end
+    end
+
+    context "without current month's file" do
+      it "uses last month's file" do
+        Dir.mktmpdir do |tmpdir|
+          last_file = File.join(tmpdir, described_class.redirects_file_name(date: Date.today << 1))
+          FileUtils.touch last_file
+          expect(described_class.default_redirects_file(directory: tmpdir))
+            .to eq(last_file)
+        end
+      end
+    end
+  end
+
   describe "#old_ids_for" do
     context "with a real file" do
       override_service(:redirect_file) do