Add initial model tests with starter fixtures for User, Family, and Account (#281)

* Add initial user fixture

* Add initial tests for  the User model

* Add initial tests for Family and a valid Account

* Pass rubocop

test/models/user_test.rb

@@ -1,7 +1,46 @@
 require "test_helper"
 
 class UserTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  def setup
+    @user = users(:bob)
+  end
+
+  test "should be valid" do
+    assert @user.valid?, @user.errors.full_messages.to_sentence
+  end
+
+  # email
+  test "email must be present" do
+    potential_user = User.new(
+      email: "david@davidbowie.com",
+      password_digest: BCrypt::Password.create("password"),
+      first_name: "David",
+      last_name: "Bowie"
+    )
+    potential_user.email = "     "
+    assert_not potential_user.valid?
+  end
+
+  test "has email address" do
+    assert_equal "bob@bobdylan.com", @user.email
+  end
+
+  test "can update email" do
+    @user.update(email: "new_email@example.com")
+    assert_equal "new_email@example.com", @user.email
+  end
+
+  test "email addresses must be unique" do
+    duplicate_user = @user.dup
+    duplicate_user.email = @user.email.upcase
+    @user.save
+    assert_not duplicate_user.valid?
+  end
+
+  test "email addresses are be saved as lower-case" do
+    mixed_case_email = "Foo@ExAMPle.CoM"
+    @user.email = mixed_case_email
+    @user.save
+    assert_equal mixed_case_email.downcase, @user.reload.email
+  end
 end