Calls to the API are checked for scope.

- Move the `Oauth2::AccessTokenValidationService` class to
  `AccessTokenValidationService`, since it is now being used for
  personal access token validation as well.

- Each API endpoint declares the scopes it accepts (if any). Currently,
  the top level API module declares the `api` scope, and the `Users` API
  module declares the `read_user` scope (for GET requests).

- Move the `find_user_by_private_token` from the API `Helpers` module to
  the `APIGuard` module, to avoid littering `Helpers` with more
  auth-related methods to support `find_user_by_private_token`

1 files changed, 42 insertions, 0 deletions

diff --git a/spec/services/access_token_validation_service_spec.rb b/spec/services/access_token_validation_service_spec.rb
new file mode 100644
index 00000000000..8808934fa24
--- /dev/null
+++ b/spec/services/access_token_validation_service_spec.rb
@@ -0,0 +1,42 @@
+require 'spec_helper'
+
+describe AccessTokenValidationService, services: true do
+
+  describe ".sufficient_scope?" do
+    it "returns true if the required scope is present in the token's scopes" do
+      token = double("token", scopes: [:api, :read_user])
+
+      expect(described_class.sufficient_scope?(token, [:api])).to be(true)
+    end
+
+    it "returns true if more than one of the required scopes is present in the token's scopes" do
+      token = double("token", scopes: [:api, :read_user, :other_scope])
+
+      expect(described_class.sufficient_scope?(token, [:api, :other_scope])).to be(true)
+    end
+
+    it "returns true if the list of required scopes is an exact match for the token's scopes" do
+      token = double("token", scopes: [:api, :read_user, :other_scope])
+
+      expect(described_class.sufficient_scope?(token, [:api, :read_user, :other_scope])).to be(true)
+    end
+
+    it "returns true if the list of required scopes contains all of the token's scopes, in addition to others" do
+      token = double("token", scopes: [:api, :read_user])
+
+      expect(described_class.sufficient_scope?(token, [:api, :read_user, :other_scope])).to be(true)
+    end
+
+    it 'returns true if the list of required scopes is blank' do
+      token = double("token", scopes: [])
+
+      expect(described_class.sufficient_scope?(token, [])).to be(true)
+    end
+
+    it "returns false if there are no scopes in common between the required scopes and the token scopes" do
+      token = double("token", scopes: [:api, :read_user])
+
+      expect(described_class.sufficient_scope?(token, [:other_scope])).to be(false)
+    end
+  end
+end