Run the `create_notes` migration

This commit resolves the previous error:

Migrations are pending. To resolve this issue, run:

        rails db:migrate RAILS_ENV=test

Before running the suggested command, this commit introduces a NOT NULL database constraint to the notes.content column, preventing it from accepting NULL values. It’s important to make this modification to the generated migration before executing the migration.

To do so, this commit adds a null: false option to the Table#text declaration, then runs the migration:

rails db:migrate

To ensure that our NOT NULL database constraint is enforced, this commit introduces our first model test.

When we execute the test, it passes:

rails test test/models/note_test.rb

When our system tests are re-run, there is a new error:

Failure:
  UserDiscoversANoteTest#test_from_the_root [/Users/seanpdoyle/src/prix-fixe/test/system/user_discovers_a_note_test.rb:9]:
  expected to find text "Hello, World" in "Share a Note"


      db/migrate/20190506032859_create_notes.rb

diff --git a/db/migrate/20190506032859_create_notes.rb b/db/migrate/20190506032859_create_notes.rb
index f639221..b9a63af 100644
--- a/db/migrate/20190506032859_create_notes.rb
+++ b/db/migrate/20190506032859_create_notes.rb
@@ -1,7 +1,7 @@
 class CreateNotes < ActiveRecord::Migration[6.0]
   def change
     create_table :notes do |t|
-      t.text :content
+      t.text :content, null: false
 
       t.timestamps
     end


      db/schema.rb

diff --git a/db/schema.rb b/db/schema.rb
index 79b5c13..2558925 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,6 +10,12 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 0) do
+ActiveRecord::Schema.define(version: 2019_05_06_032859) do
+
+  create_table "notes", force: :cascade do |t|
+    t.text "content", null: false
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+  end
 
 end


      test/models/note_test.rb

diff --git a/test/models/note_test.rb b/test/models/note_test.rb
index 7bbab53..42a53e2 100644
--- a/test/models/note_test.rb
+++ b/test/models/note_test.rb
@@ -1,7 +1,11 @@
 require 'test_helper'
 
 class NoteTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "NOT NULL database constraint on notes.content" do
+    note = Note.new
+
+    exercise = -> { note.save! }
+
+    assert_raises(ActiveRecord::NotNullViolation, /content/, &exercise)
+  end
 end

Run the create_notes migration

Run the `create_notes` migration