add tests

test/models/user_test.rb

@@ -1,7 +1,34 @@
 require "test_helper"
 
 class UserTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "should be valid with an email and password" do
+    user = User.new(email: "test@example.com", password: "password")
+    assert user.valid?
+  end
+
+  test "should be invalid without an email" do
+    user = User.new(password: "password")
+    assert_not user.valid?
+  end
+
+  test "should be invalid with a duplicate email" do
+    User.create(email: "test@example.com", password: "password")
+    user = User.new(email: "test@example.com", password: "password")
+    assert_not user.valid?
+  end
+
+  test "should have a default role of contributor" do
+    user = User.new(email: "test@example.com", password: "password")
+    assert user.contributor?
+  end
+
+  test "can be a reviewer" do
+    user = User.new(email: "test@example.com", password: "password", role: :reviewer)
+    assert user.reviewer?
+  end
+
+  test "can be an admin" do
+    user = User.new(email: "test@example.com", password: "password", role: :admin)
+    assert user.admin?
+  end
 end