1 files changed, 31 insertions, 0 deletions
diff --git a/spec/bundler/support/artifice/compact_index_concurrent_download.rb b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
new file mode 100644
index 0000000000..b788a852cf
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexConcurrentDownload < CompactIndexAPI
+  get "/versions" do
+    versions = File.join(Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
+      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "versions")
+
+    # Verify the original (empty) content hasn't been deleted, e.g. on a retry
+    File.read(versions) == "" || raise("Original file should be present and empty")
+
+    # Verify this is only requested once for a partial download
+    env["HTTP_RANGE"] || raise("Missing Range header for expected partial download")
+
+    # Overwrite the file in parallel, which should be then overwritten
+    # after a successful download to prevent corruption
+    File.open(versions, "w") {|f| f.puts "another process" }
+
+    etag_response do
+      file = tmp("versions.list")
+      file.delete if file.file?
+      file = CompactIndex::VersionsFile.new(file.to_s)
+      file.create(gems)
+      file.contents
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexConcurrentDownload)