Ensure post owner doesn't change when a post is modified

app/controllers/posts_controller.rb

@@ -226,7 +226,7 @@ def post_from_form(params)
     time = params[:post][:time]
     post.datetime = DateTime.parse("#{date} #{time}")
     post.content = params[:post][:content]
-    post.author = current_user
+    post.author = current_user unless !!post.author
     post
   end
 

test/system/editing_posts_test.rb

@@ -0,0 +1,58 @@
+require "application_system_test_case"
+require_relative 'systemtest_helpers.rb'
+
+class EditingPostsTest < ApplicationSystemTestCase
+  test_users = {
+    washington: {email: "[email protected]", pass: "georgepass"}, # admin
+    jackson: {email: "[email protected]", pass: "jacksonpass"},      # publisher
+    lincoln: {email: "[email protected]", pass: "lincolnpass"}     # subscriber
+  }
+
+  test "publisher and admin can edit their own posts" do
+    [test_users[:washington], test_users[:jackson]].each do |test_user|
+      log_in_with test_user
+      click_on "New Post Button"
+      m = "#{rand} I cannot tell a lie!"
+      fill_in "post_content", with: m
+      click_on "Save Post"
+      assert_text m # page previw shows post content
+      click_on "Home"
+      assert_text m # recent posts page also shows content of new post"
+      ## Find edit button
+      ## click edit button
+      ## change post content
+      ## validate new post content is saved
+      click_on "Logout"
+    end
+  end
+
+  test "admin editing a post doesn't change ownership of the post" do
+    log_in_with test_users[:jackson] #publisher
+    click_on "New Post Button"
+    m = "#{rand} I cannot tell a lie"
+    fill_in "post_content", with: m
+    click_on "Save Post"
+    assert_text m # page previw shows post content
+    post_url = current_url
+    click_on "Logout"
+
+    log_in_with test_users[:washington] #admin
+      visit post_url
+      click_on "Edit"
+      m2 = "#{rand} what a lie"
+      fill_in "post_content", with: m2
+      click_on "Save Post"
+      assert_text m2
+    click_on "Logout"
+
+    log_in_with test_users[:jackson] #publisher
+      visit post_url
+      click_on "Edit"
+      m3 = "#{rand} no lies here"
+      fill_in "post_content", with: m3
+      click_on "Save Post"
+      assert_text m3
+    click_on "Logout"
+
+  end
+end