diff --git a/Library/Homebrew/test/cache_store_spec.rb b/Library/Homebrew/test/cache_store_spec.rb
new file mode 100644
index 0000000000..6b54f45854
--- /dev/null
+++ b/Library/Homebrew/test/cache_store_spec.rb
@@ -0,0 +1,146 @@
+require "cache_store"
+
+describe CacheStoreDatabase do
+  subject { CacheStoreDatabase.new(:sample) }
+
+  describe "self.use" do
+    let(:type) { :test }
+
+    it "creates a new `DatabaseCache` instance and yields it" do
+      cache_store = double("cache_store", close_if_open!: nil)
+      expect(CacheStoreDatabase).to receive(:new).with(type).and_return(cache_store)
+      expect(CacheStoreDatabase).to receive(:call).with(cache_store)
+    end
+  end
+
+  describe "#set" do
+    let(:db) { double("db", :[]= => nil) }
+
+    before(:each) do
+      allow(File).to receive(:write)
+      allow(subject).to receive(:created?).and_return(true)
+      expect(db).to receive(:has_key?).with(:foo).and_return(false)
+      subject.stub(:db).and_return(db)
+    end
+
+    it "sets the value in the `CacheStoreDatabase`" do
+      expect(db).to_not have_key(:foo)
+      subject.set(:foo, "bar")
+    end
+  end
+
+  describe "#get" do
+    context "database created" do
+      let(:db) { double("db", :[] => "bar") }
+
+      before(:each) do
+        allow(subject).to receive(:created?).and_return(true)
+        expect(db).to receive(:has_key?).with(:foo).and_return(true)
+        subject.stub(:db).and_return(db)
+      end
+
+      it "gets value in the `CacheStoreDatabase` corresponding to the key" do
+        expect(db).to have_key(:foo)
+        expect(subject.get(:foo)).to equal("bar")
+      end
+    end
+
+    context "database not created" do
+      let(:db) { double("db", :[] => nil) }
+
+      before(:each) do
+        allow(subject).to receive(:created?).and_return(false)
+        subject.stub(:db).and_return(db)
+      end
+
+      it "does not get value in the `CacheStoreDatabase` corresponding to key" do
+        expect(subject.get(:foo)).to_not be("bar")
+      end
+
+      it "does not call `db[]` if `CacheStoreDatabase.created?` is `false`" do
+        expect(db).not_to receive(:[])
+        subject.get(:foo)
+      end
+    end
+  end
+
+  describe "#delete" do
+    context "database created" do
+      let(:db) { double("db", :[] => { foo: "bar" }) }
+
+      before(:each) do
+        allow(subject).to receive(:created?).and_return(true)
+        subject.stub(:db).and_return(db)
+      end
+
+      it "deletes value in the `CacheStoreDatabase` corresponding to the key" do
+        expect(db).to receive(:delete).with(:foo)
+        subject.delete(:foo)
+      end
+    end
+
+    context "database not created" do
+      let(:db) { double("db", delete: nil) }
+
+      before(:each) do
+        allow(subject).to receive(:created?).and_return(false)
+        subject.stub(:db).and_return(db)
+      end
+
+      it "does not call `db.delete` if `CacheStoreDatabase.created?` is `false`" do
+        expect(db).not_to receive(:delete)
+        subject.delete(:foo)
+      end
+    end
+  end
+
+  describe "#close_if_open!" do
+    context "database open" do
+      before(:each) do
+        subject.instance_variable_set(:@db, instance_double("db", close: nil))
+      end
+
+      it "does not raise an error when `close` is called on the database" do
+        expect { subject.close_if_open! }.to_not raise_error(NoMethodError)
+      end
+    end
+
+    context "database not open" do
+      before(:each) do
+        subject.instance_variable_set(:@db, nil)
+      end
+
+      it "does not raise an error when `close` is called on the database" do
+        expect { subject.close_if_open! }.to_not raise_error(NoMethodError)
+      end
+    end
+  end
+
+  describe "#created?" do
+    let(:cache_path) { "path/to/homebrew/cache/sample.db" }
+
+    before(:each) do
+      subject.stub(:cache_path).and_return(cache_path)
+    end
+
+    context "`File.exist?(cache_path)` returns `true`" do
+      before(:each) do
+        allow(File).to receive(:exist?).with(cache_path).and_return(true)
+      end
+
+      it "returns `true`" do
+        expect(subject.created?).to be(true)
+      end
+    end
+
+    context "`File.exist?(cache_path)` returns `false`" do
+      before(:each) do
+        allow(File).to receive(:exist?).with(cache_path).and_return(false)
+      end
+
+      it "returns `false`" do
+        expect(subject.created?).to be(false)
+      end
+    end
+  end
+end
diff --git a/Library/Homebrew/test/linkage_cache_store_spec.rb b/Library/Homebrew/test/linkage_cache_store_spec.rb
new file mode 100644
index 0000000000..cfd3cc7f93
--- /dev/null
+++ b/Library/Homebrew/test/linkage_cache_store_spec.rb
@@ -0,0 +1,88 @@
+require "test/support/fixtures/testball"
+require "linkage_cache_store"
+
+describe LinkageCacheStore do
+  let(:keg_name) { "keg_name" }
+  let(:database) { double("database") }
+
+  subject { LinkageCacheStore.new(keg_name, database) }
+
+  describe "#keg_exists?" do
+    context "`keg_name` exists in cache" do
+      before(:each) do
+        expect(database).to receive(:get).with(keg_name).and_return("")
+      end
+
+      it "returns `true`" do
+        expect(subject.keg_exists?).to be(true)
+      end
+    end
+
+    context "`keg_name` does not exist in cache" do
+      before(:each) do
+        expect(database).to receive(:get).with(keg_name).and_return(nil)
+      end
+
+      it "returns `false`" do
+        expect(subject.keg_exists?).to be(false)
+      end
+    end
+  end
+
+  describe "#update!" do
+    context "a `value` is a `Hash`" do
+      it "sets the cache for the `keg_name`" do
+        expect(database).to receive(:set).with(keg_name, anything)
+        subject.update!(a_value: { key: ["value"] })
+      end
+    end
+
+    context "a `value` is an `Array`" do
+      it "sets the cache for the `keg_name`" do
+        expect(database).to receive(:set).with(keg_name, anything)
+        subject.update!(a_value: ["value"])
+      end
+    end
+
+    context "a `value` is not an `Array` or `Hash`" do
+      it "raises a `TypeError` if a `value` is not an `Array` or `Hash`" do
+        expect { subject.update!(key: 1) }.to raise_error(TypeError)
+      end
+    end
+  end
+
+  describe "#flush_cache!" do
+    it "calls `delete` on the `database` with `keg_name` as parameter" do
+      expect(database).to receive(:delete).with(keg_name)
+      subject.flush_cache!
+    end
+  end
+
+  describe "#fetch_type" do
+    context "`HASH_LINKAGE_TYPES.include?(type)`" do
+      before(:each) do
+        expect(database).to receive(:get).with(keg_name).and_return(nil)
+      end
+
+      it "returns a `Hash` of values" do
+        expect(subject.fetch_type(:brewed_dylibs)).to be_an_instance_of(Hash)
+      end
+    end
+
+    context "`ARRAY_LINKAGE_TYPES.include?(type)`" do
+      before(:each) do
+        expect(database).to receive(:get).with(keg_name).and_return(nil)
+      end
+
+      it "returns an `Array` of values" do
+        expect(subject.fetch_type(:system_dylibs)).to be_an_instance_of(Array)
+      end
+    end
+
+    context "`type` not in `HASH_LINKAGE_TYPES` or `ARRAY_LINKAGE_TYPES`" do
+      it "raises a `TypeError` if the `type` is not supported" do
+        expect { subject.fetch_type(:bad_type) }.to raise_error(TypeError)
+      end
+    end
+  end
+end