Add unit test for gem installer

Change-Id: Ibf4a53b9f687882f84932433cc3d45e084e3a29e
Signed-off-by: Maxime Brugidou <m.brugidou@criteo.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/spec/unit/cookbook/gem_installer_spec.rb b/spec/unit/cookbook/gem_installer_spec.rb
new file mode 100644
index 0000000000..69b714d977
--- /dev/null
+++ b/spec/unit/cookbook/gem_installer_spec.rb
@@ -0,0 +1,70 @@
+require "spec_helper"
+require "bundler/dsl"
+
+describe Chef::Cookbook::GemInstaller do
+  let(:cookbook_collection) do
+    {
+      test: double(
+        :cookbook,
+        metadata: double(
+          :metadata,
+          gems: [["httpclient"], ["nokogiri"]]
+        )
+      ),
+      test2: double(
+        :cookbook,
+        metadata: double(
+          :metadata,
+          gems: [["httpclient", ">= 2.0"]]
+        )
+      ),
+      test3: double(
+        :cookbook,
+        metadata: double(
+          :metadata,
+          gems: [["httpclient", ">= 1.0"]]
+        )
+      ),
+    }
+  end
+
+  let(:gem_installer) do
+    described_class.new(cookbook_collection, Chef::EventDispatch::Dispatcher.new)
+  end
+
+  let(:gemfile) do
+    StringIO.new
+  end
+
+  let(:shell_out) do
+    double(:shell_out, stdout: "")
+  end
+
+  let(:bundler_dsl) do
+    b = Bundler::Dsl.new
+    b.instance_eval(gemfile.string)
+    b
+  end
+
+  before(:each) do
+    # Prepare mocks: using a StringIO instead of a File
+    expect(Dir).to receive(:mktmpdir).and_yield("")
+    expect(File).to receive(:open).and_yield(gemfile)
+    expect(gemfile).to receive(:path).and_return("")
+    expect(IO).to receive(:read).and_return("")
+    expect(gem_installer).to receive(:shell_out!).and_return(shell_out)
+
+  end
+
+  it "generates a valid Gemfile" do
+    expect { gem_installer.install }.to_not raise_error
+
+    expect { bundler_dsl }.to_not raise_error
+  end
+
+  it "generate a Gemfile with all constraints" do
+    expect { gem_installer.install }.to_not raise_error
+
+    expect(bundler_dsl.dependencies.find { |d| d.name == "httpclient" }.requirements_list.length).to eql(2)
+  end
+end