Retry on client errors

lib/imap/backup/account/folder.rb

@@ -14,6 +14,8 @@ class Account::Folder
     BODY_ATTRIBUTE = "BODY[]".freeze
     UID_FETCH_RETRY_CLASSES = [EOFError, Errno::ECONNRESET, IOError].freeze
     APPEND_RETRY_CLASSES = [Net::IMAP::BadResponseError].freeze
+    CREATE_RETRY_CLASSES = [Net::IMAP::BadResponseError].freeze
+    EXAMINE_RETRY_CLASSES = [Net::IMAP::BadResponseError].freeze
     PERMITTED_FLAGS = %i(Answered Draft Flagged Seen).freeze
 
     attr_reader :connection
@@ -33,7 +35,9 @@ def folder
     end
 
     def exist?
-      examine
+      retry_on_error(errors: EXAMINE_RETRY_CLASSES) do
+        examine
+      end
       true
     rescue FolderNotFound
       false
@@ -42,7 +46,9 @@ def exist?
     def create
       return if exist?
 
-      client.create(utf7_encoded_name)
+      retry_on_error(errors: CREATE_RETRY_CLASSES) do
+        client.create(utf7_encoded_name)
+      end
     end
 
     def uid_validity

lib/imap/backup/version.rb

@@ -2,7 +2,7 @@ module Imap; end
 
 module Imap::Backup
   MAJOR    = 9
-  MINOR    = 2
+  MINOR    = 3
   REVISION = 0
   PRE      = nil
   VERSION  = [MAJOR, MINOR, REVISION, PRE].compact.map(&:to_s).join(".")

spec/unit/imap/backup/account/folder_spec.rb

@@ -31,6 +31,10 @@ module Imap::Backup
     let(:responses) { [] }
     let(:append_response) { nil }
     let(:uids) { [5678, 123] }
+    let(:bad_response_error_response) do
+      response_text = Net::IMAP::ResponseText.new(42, "BOOM")
+      Net::IMAP::TaggedResponse.new("BAD", "name", response_text, "BOOM")
+    end
 
     before { allow(client).to receive(:uid_search).with(["ALL"]) { uids } }
 
@@ -169,6 +173,22 @@ module Imap::Backup
           expect(subject.exist?).to be_falsey
         end
       end
+
+      context "when the examine fails with a BadResponseError" do
+        before do
+          outcomes = [
+            -> { raise Net::IMAP::BadResponseError, bad_response_error_response },
+            -> {}
+          ]
+          allow(client).to receive(:examine) { outcomes.shift.call }
+        end
+
+        it "retries" do
+          subject.create
+
+          expect(client).to have_received(:examine).twice
+        end
+      end
     end
 
     describe "#create" do
@@ -197,6 +217,22 @@ module Imap::Backup
 
           subject.create
         end
+
+        context "when the create fails with a BadResponseError" do
+          before do
+            outcomes = [
+              -> { raise Net::IMAP::BadResponseError, bad_response_error_response },
+              -> {}
+            ]
+            allow(client).to receive(:create) { outcomes.shift.call }
+          end
+
+          it "retries" do
+            subject.create
+
+            expect(client).to have_received(:create).twice
+          end
+        end
       end
     end
 
@@ -278,11 +314,7 @@ module Imap::Backup
       context "when the append fails with a BadResponseError" do
         before do
           outcomes = [
-            -> do
-              response_text = Net::IMAP::ResponseText.new(42, "BOOM")
-              response = Net::IMAP::TaggedResponse.new("BAD", "name", response_text, "BOOM")
-              raise Net::IMAP::BadResponseError, response
-            end,
+            -> { raise Net::IMAP::BadResponseError, bad_response_error_response },
             -> { append_response }
           ]
           allow(client).to receive(:append) { outcomes.shift.call }