Added tests for os_prefix_ci

Library/Homebrew/test/utils/analytics_spec.rb

@@ -0,0 +1,34 @@
+require "utils/analytics"
+
+describe Utils::Analytics do
+  describe "::os_prefix_ci" do
+    context "when anonymous_os_prefix_ci is not set" do
+      it "returns OS_VERSION and prefix when HOMEBREW_PREFIX is not /usr/local" do
+        expect(described_class.os_prefix_ci).to include("#{OS_VERSION}, non-/usr/local")
+      end
+
+      it "includes CI when ENV['CI'] is set" do
+        allow(ENV).to receive(:[]).with("CI").and_return("true")
+        expect(described_class.os_prefix_ci).to include("CI")
+      end
+
+      it "does not include prefix when HOMEBREW_PREFIX is usr/local" do
+        allow(HOMEBREW_PREFIX).to receive(:to_s).and_return("/usr/local")
+        expect(described_class.os_prefix_ci).not_to include("non-/usr/local")
+      end
+    end
+
+    context "when anonymous_os_prefix_ci is set" do
+      let(:anonymous_os_prefix_ci) { "macOS 10.11.6, non-/usr/local, CI" }
+
+      it "returns anonymous_os_prefix_ci" do
+        described_class.instance_variable_set(:@anonymous_os_prefix_ci, anonymous_os_prefix_ci)
+        expect(described_class.os_prefix_ci).to eq(anonymous_os_prefix_ci)
+      end
+    end
+  end
+
+  describe "::" do
+    
+  end
+end