inline the list and list_items migrations for dwyl/app#271

src/mvp/16-lists.md

@@ -1,8 +1,8 @@
 # Lists
 
-Our **MVP `App`** already has 
+Our **MVP App** already has 
 much of the basic functionality we need/want 
-but it's sorely lacking 
+but is sorely lacking 
 a way to **_organize_ `items`** 
 into distinct projects/areas.
 Let's fix that by introducing `lists`!
@@ -44,14 +44,60 @@ that will make the `App` more _useful_ both to individuals and teams.
 
 Create the `lists` and `list_items` tables
 with the following 
-[**`mix phx.gen.schema`**](https://hexdocs.pm/phoenix/Mix.Tasks.Phx.Gen.Schema.html)
+[`mix phx.gen.schema`](https://hexdocs.pm/phoenix/Mix.Tasks.Phx.Gen.Schema.html)
 commands:
 
 ```sh
 mix phx.gen.schema List lists person_id:integer status:integer text:string
 mix phx.gen.schema ListItems list_items item_id:references:items list_id:references:lists person_id:integer position:float
 ```
 
+Those two commands will create the following migrations:
+
+[`20230416001029_create_lists.exs`](https://github.com/dwyl/mvp/blob/fa0b79eebbe582e3b24213a2c657d0fc343782c9/priv/repo/migrations/20230416001029_create_lists.exs)
+
+```elixir
+defmodule App.Repo.Migrations.CreateLists do
+  use Ecto.Migration
+
+  def change do
+    create table(:lists) do
+      add :text, :string
+      add :person_id, :integer
+      add :status, :integer
+
+      timestamps()
+    end
+  end
+end
+```
+
+[`20230416001045_create_list_items.exs`](https://github.com/dwyl/mvp/blob/54aff67d172ad372c5ee1ffd9c41f24b093b78d4/priv/repo/migrations/20230416001045_create_list_items.exs)
+
+```elixir
+defmodule App.Repo.Migrations.CreateListItems do
+  use Ecto.Migration
+
+  def change do
+    create table(:list_items) do
+      add :person_id, :integer
+      add :position, :float
+      add :item_id, references(:items, on_delete: :nothing)
+      add :list_id, references(:lists, on_delete: :nothing)
+
+      timestamps()
+    end
+
+    create index(:list_items, [:item_id])
+    create index(:list_items, [:list_id])
+  end
+end
+```
+
+The Database tables these migrations create 
+are very simple.
+
+
 Once we run `mix ecto.migrate`,
 we have the following database
 ERD:
@@ -65,7 +111,7 @@ to build the `lists` features. 🎉
 ## Create Tests (TDD)
 
 The `gen.schema` command only creates the migration files
-and the corresponding schema in the 
+and the corresponding schema files in the 
 [`lib/app`](https://github.com/dwyl/mvp/tree/main/lib/app) 
 directory of our `Phoenix App`.
 It does not create any `CRUD` functions or tests.
@@ -76,6 +122,14 @@ We _manually_ created the following test files:
 + test/app/list_test.exs
 + test/app/list_items_test.exs
 
+Inside the test files we have all the tests necessary 
+to build the _baseline_ `lists` features. 
+e.g:
+
+```elixir
+
+```
+
 > **TODO**: hyperlink these two files, once they are merged into `main`.
 
 Rather than _duplicating_ large blocks of test code here,
@@ -110,16 +164,20 @@ def create_list(attrs) do
 end
 ```
 
+The `attrs` are just
+`person_id` the `id` of the `person` creating the list, 
+`text` the name/description of the list 
+and `status` (optional).
+
 If you are new to the `PaperTrail` package and the benefits it offers,
 we wrote a quick intro:
 [dwyl/phoenix-papertrail-demo](https://github.com/dwyl/phoenix-papertrail-demo)
 
 The gist is this: it gives us version history for records in our database
-without significant query overhead. 
+without any query overhead. 
 
 ## `add_list_item/4`
 
-
 `add_list_item/4` as you would expect,
 adds an `item` to a `list` for the given `person_id`
 
@@ -140,7 +198,7 @@ The first 3 arguments are self-explanatory;
 the final one, `position` is there to help us _order_ the `list`!
 As you may have noticed in the `mix gen.schema` command above
 for the `list_items` table, the `position` field is a `Float`. 
-e.g: `1.0` 
+e.g: `1.0`. 
 We have very deliberately chosen a `Float` not an `Integer`
 so that we can use this for easy append-only positional sorting. 
 More on this later in the "Reordering" chapter. 
@@ -152,4 +210,3 @@ see:
 
 
 
-