Test Gitlab::ReplyByEmail.

spec/lib/gitlab/reply_by_email_spec.rb

+require "spec_helper"
+
+describe Gitlab::ReplyByEmail do
+  describe "self.enabled?" do
+    context "when reply by email is enabled" do
+      before do
+        allow(Gitlab.config.reply_by_email).to receive(:enabled).and_return(true)
+      end
+
+      context "when the address is valid" do
+        before do
+          allow(Gitlab.config.reply_by_email).to receive(:address).and_return("replies+%{reply_key}@example.com")
+        end
+
+        it "returns true" do
+          expect(described_class.enabled?).to be_truthy
+        end
+      end
+
+      context "when the address is invalid" do
+        before do
+          allow(Gitlab.config.reply_by_email).to receive(:address).and_return("replies@example.com")
+        end
+
+        it "returns false" do
+          expect(described_class.enabled?).to be_falsey
+        end
+      end
+    end
+
+    context "when reply by email is disabled" do
+      before do
+        allow(Gitlab.config.reply_by_email).to receive(:enabled).and_return(false)
+      end
+
+      it "returns false" do
+        expect(described_class.enabled?).to be_falsey
+      end
+    end
+  end
+
+  describe "self.reply_key" do
+    context "when enabled" do
+      before do
+        allow(described_class).to receive(:enabled?).and_return(true)
+      end
+
+      it "returns a random hex" do
+        key = described_class.reply_key
+        key2 = described_class.reply_key
+
+        expect(key).not_to eq(key2)
+      end
+    end
+
+    context "when disabled" do
+      before do
+        allow(described_class).to receive(:enabled?).and_return(false)
+      end
+
+      it "returns nil" do
+        expect(described_class.reply_key).to be_nil
+      end
+    end
+  end
+
+  context "self.reply_address" do
+    before do
+      allow(Gitlab.config.reply_by_email).to receive(:address).and_return("replies+%{reply_key}@example.com")
+    end
+
+    it "returns the address with an interpolated reply key" do
+      expect(described_class.reply_address("key")).to eq("replies+key@example.com")
+    end
+  end
+
+  context "self.reply_key_from_address" do
+    before do
+      allow(Gitlab.config.reply_by_email).to receive(:address).and_return("replies+%{reply_key}@example.com")
+    end
+
+    it "returns reply key" do
+      expect(described_class.reply_key_from_address("replies+key@example.com")).to eq("key")
+    end
+  end
+end