account for posts with replacement files

app/jobs/domain/e621/job/posts_index_job.rb

@@ -73,15 +73,21 @@ module Domain::E621::Job
 
       e621_md5 = post_json["file"]["md5"]
       if post.md5 && post.md5 != e621_md5
-        logger.error(
-          "[ id: #{post.id} / e621_id: #{post.e621_id} ] " +
-            "md5 mismatch for post: #{post.md5} != #{e621_md5}"
+        logger.warn(
+          "md5 changed for post: #{post.md5.to_s.bold} => #{e621_md5.to_s.bold}"
         )
-        return false
+        post.state_detail["prev_md5s"] ||= []
+        post.state_detail["prev_md5s"] << {
+          "md5" => post.md5,
+          "file_id" => post.file_id,
+        }
+        post.file = nil
+        file_changed = true
       else
-        post.md5 = e621_md5
+        file_changed = false
       end
 
+      post.md5 = e621_md5
       post.file_url_str ||= post_json["file"]["url"]
       post.description = post_json["description"]
       post.rating = post_json["rating"]
@@ -112,7 +118,7 @@ module Domain::E621::Job
       defer_job(Domain::E621::Job::StaticFileJob, {
         post: post,
         caused_by_entry: @log_entry,
-      }) if new_record
+      }) if new_record || file_changed
 
       true
     end

spec/jobs/domain/e621/job/posts_index_job_spec.rb

@@ -50,6 +50,9 @@ describe Domain::E621::Job::PostsIndexJob do
       post.save!
 
       perform_now({})
+      expect(SpecUtil.enqueued_jobs(
+        Domain::E621::Job::StaticFileJob
+      ).length).to eq(4)
 
       post.reload
       # removes the tag1 tag
@@ -64,5 +67,27 @@ describe Domain::E621::Job::PostsIndexJob do
         tagging.tag.name == "mammal"
       }.category).to eq("cat_species")
     end
+
+    it "updates a post where the md5 has changed" do
+      file = SpecUtil.create_http_log_entry
+      post = Domain::E621::Post.create!({
+        e621_id: 4247443,
+        md5: "0000000051668681e9697a48144d7c78",
+        file: file,
+      })
+      perform_now({})
+      post.reload
+      expect(post.md5).to eq("1c6169aa51668681e9697a48144d7c78")
+      expect(post.file).to be_nil
+      expect(post.state_detail["prev_md5s"]).to eq([
+        "md5" => "0000000051668681e9697a48144d7c78",
+        "file_id" => file.id,
+      ])
+      static_file_jobs = SpecUtil.enqueued_jobs(Domain::E621::Job::StaticFileJob)
+      expect(static_file_jobs.length).to eq(5)
+      expect(static_file_jobs).to match(
+        including(including(args: [including(post: post)]))
+      )
+    end
   end
 end