add tests

test/models/entry_version_test.rb

@@ -1,7 +1,36 @@
 require "test_helper"
 
 class EntryVersionTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "should be valid with all attributes" do
+    version = EntryVersion.new(
+      entry: entries(:one),
+      user: users(:one),
+      changes_made: { "fi" => "uusi sana" }
+    )
+    assert version.valid?
+  end
+
+  test "should be invalid without changes_made" do
+    version = EntryVersion.new(
+      entry: entries(:one),
+      user: users(:one)
+    )
+    assert_not version.valid?
+  end
+
+  test "should be invalid without an entry" do
+    version = EntryVersion.new(
+      user: users(:one),
+      changes_made: { "fi" => "uusi sana" }
+    )
+    assert_not version.valid?
+  end
+
+  test "should be invalid without a user" do
+    version = EntryVersion.new(
+      entry: entries(:one),
+      changes_made: { "fi" => "uusi sana" }
+    )
+    assert_not version.valid?
+  end
 end