1 files changed, 36 insertions, 0 deletions
diff --git a/spec/support/helpers/stub_env.rb b/spec/support/helpers/stub_env.rb
new file mode 100644
index 00000000000..36b90fc68d6
--- /dev/null
+++ b/spec/support/helpers/stub_env.rb
@@ -0,0 +1,36 @@
+# Inspired by https://github.com/ljkbennett/stub_env/blob/master/lib/stub_env/helpers.rb
+module StubENV
+  def stub_env(key_or_hash, value = nil)
+    init_stub unless env_stubbed?
+
+    if key_or_hash.is_a? Hash
+      key_or_hash.each { |k, v| add_stubbed_value(k, v) }
+    else
+      add_stubbed_value key_or_hash, value
+    end
+  end
+
+  private
+
+  STUBBED_KEY = '__STUBBED__'.freeze
+
+  def add_stubbed_value(key, value)
+    allow(ENV).to receive(:[]).with(key).and_return(value)
+    allow(ENV).to receive(:key?).with(key).and_return(true)
+    allow(ENV).to receive(:fetch).with(key).and_return(value)
+    allow(ENV).to receive(:fetch).with(key, anything()) do |_, default_val|
+      value || default_val
+    end
+  end
+
+  def env_stubbed?
+    ENV[STUBBED_KEY]
+  end
+
+  def init_stub
+    allow(ENV).to receive(:[]).and_call_original
+    allow(ENV).to receive(:key?).and_call_original
+    allow(ENV).to receive(:fetch).and_call_original
+    add_stubbed_value(STUBBED_KEY, true)
+  end
+end