Add a Gitlab::Git::Env to store Git-specific env thread-safely

Signed-off-by: Rémy Coutable <remy@rymai.me>

1 files changed, 102 insertions, 0 deletions

diff --git a/spec/lib/gitlab/git/env_spec.rb b/spec/lib/gitlab/git/env_spec.rb
new file mode 100644
index 00000000000..d9df99bfe05
--- /dev/null
+++ b/spec/lib/gitlab/git/env_spec.rb
@@ -0,0 +1,102 @@
+require 'spec_helper'
+
+describe Gitlab::Git::Env do
+  describe "#set" do
+    context 'with RequestStore.store disabled' do
+      before do
+        allow(RequestStore).to receive(:active?).and_return(false)
+      end
+
+      it 'does not store anything' do
+        described_class.set(GIT_OBJECT_DIRECTORY: 'foo')
+
+        expect(described_class.all).to be_empty
+      end
+    end
+
+    context 'with RequestStore.store enabled' do
+      before do
+        allow(RequestStore).to receive(:active?).and_return(true)
+      end
+
+      it 'whitelist some `GIT_*` variables and stores them using RequestStore' do
+        described_class.set(
+          GIT_OBJECT_DIRECTORY: 'foo',
+          GIT_ALTERNATE_OBJECT_DIRECTORIES: 'bar',
+          GIT_EXEC_PATH: 'baz',
+          PATH: '~/.bin:/bin')
+
+        expect(described_class[:GIT_OBJECT_DIRECTORY]).to eq('foo')
+        expect(described_class[:GIT_ALTERNATE_OBJECT_DIRECTORIES]).to eq('bar')
+        expect(described_class[:GIT_EXEC_PATH]).to be_nil
+        expect(described_class[:bar]).to be_nil
+      end
+    end
+  end
+
+  describe "#all" do
+    context 'with RequestStore.store enabled' do
+      before do
+        allow(RequestStore).to receive(:active?).and_return(true)
+        described_class.set(
+          GIT_OBJECT_DIRECTORY: 'foo',
+          GIT_ALTERNATE_OBJECT_DIRECTORIES: 'bar')
+      end
+
+      it 'returns an env hash' do
+        expect(described_class.all).to eq({
+          'GIT_OBJECT_DIRECTORY' => 'foo',
+          'GIT_ALTERNATE_OBJECT_DIRECTORIES' => 'bar'
+        })
+      end
+    end
+  end
+
+  describe "#[]" do
+    context 'with RequestStore.store enabled' do
+      before do
+        allow(RequestStore).to receive(:active?).and_return(true)
+      end
+
+      before do
+        described_class.set(
+          GIT_OBJECT_DIRECTORY: 'foo',
+          GIT_ALTERNATE_OBJECT_DIRECTORIES: 'bar')
+      end
+
+      it 'returns a stored value for an existing key' do
+        expect(described_class[:GIT_OBJECT_DIRECTORY]).to eq('foo')
+      end
+
+      it 'returns nil for an non-existing key' do
+        expect(described_class[:foo]).to be_nil
+      end
+    end
+  end
+
+  describe 'thread-safety' do
+    context 'with RequestStore.store enabled' do
+      before do
+        allow(RequestStore).to receive(:active?).and_return(true)
+        described_class.set(GIT_OBJECT_DIRECTORY: 'foo')
+      end
+
+      it 'is thread-safe' do
+        another_thread = Thread.new do
+          described_class.set(GIT_OBJECT_DIRECTORY: 'bar')
+
+          Thread.stop
+          described_class[:GIT_OBJECT_DIRECTORY]
+        end
+
+        # Ensure another_thread runs first
+        sleep 0.1 until another_thread.stop?
+
+        expect(described_class[:GIT_OBJECT_DIRECTORY]).to eq('foo')
+
+        another_thread.run
+        expect(another_thread.value).to eq('bar')
+      end
+    end
+  end
+end