docs: update docs for mix tasks

documentation/topics/development/migrations-and-tasks.md

@@ -6,32 +6,19 @@
 
 ## Tasks
 
-The available tasks are:
-
-- `mix ash_postgres.generate_migrations`
-- `mix ash_postgres.create`
-- `mix ash_postgres.drop`
-- `mix ash_postgres.migrate` (use `mix ash_postgres.migrate --tenants` to run tenant migrations)
-
-AshPostgres is built on top of ecto, so much of its behavior is pass-through/orchestration of that tooling.
+Ash comes with its own tasks, and AshPostgres exposes lower level tasks that you can use if necessary. This guide shows the process using `ash.*` tasks, and the `ash_postgres.*` tasks are illustrated at the bottom.
 
 ## Basic Workflow
 
 - Make resource changes
-- Run `mix ash_postgres.generate_migrations` to generate migrations and resource snapshots
-- Run `mix ash_postgres.migrate` to run those migrations
-- Run `mix ash_postgres.migrate --tenants` _as well_ if you have multi-tenant resources.
+- Run `mix ash.codegen --name add_a_combobulator` to generate migrations and resource snapshots
+- Run `mix ash.migrate` to run those migrations
 
-For more information on generating migrations, see the module documentation here:
-`Mix.Tasks.AshPostgres.GenerateMigrations`, or run `mix help ash_postgres.generate_migrations`
+For more information on generating migrations, run `mix help ash_postgres.generate_migrations` (the underlying task that is called by `mix ash.migrate`)
 
-For running your migrations, there is a mix task that will find all of the repos configured in your domains and run their
-migrations. It is a thin wrapper around `mix ecto.migrate`. Ours is called `mix ash_postgres.migrate`
-
-If you want to run or rollback individual migrations, use the corresponding
-
-For tenant migrations (see the multitenancy guides for more) generated by multitenant resources, make sure you are using
-`mix ash_postgres.generate_migrations`. It is not sufficient to run `mix ash_postgres.migrate --migrations_path tenant_migrations_path`. You will also need to define a `list_tenants/0` function in your repo module. See `AshPostgres.Repo` for more.
+> ### list_tenants/0 {: .info}
+>
+> If you have are using schema-based multitenancy, you will also need to define a `list_tenants/0` function in your repo module. See `AshPostgres.Repo` for more.
 
 ### Regenerating Migrations
 
@@ -44,28 +31,23 @@ Often, you will run into a situation where you want to make a slight change to a
 N_MIGRATIONS=$(git ls-files --others priv/repo/migrations | wc -l)
 
 # Rollback untracked migrations
-mix ecto.rollback -n $N_MIGRATIONS
+mix ash_postgres.rollback -n $N_MIGRATIONS
 
 # Delete untracked migrations and snapshots
 git ls-files --others priv/repo/migrations | xargs rm
 git ls-files --others priv/resource_snapshots | xargs rm
 
 # Regenerate migrations
-mix ash_postgres.generate_migrations
+mix ash.codegen --name $1
 
 # Run migrations if flag
 if echo $* | grep -e "-m" -q
 then
-  mix ecto.migrate
+  mix ash.migrate
 fi
 ```
 
-After saving this file to something like `regen.sh`, make it executable with `chmod +x regen.sh`. Now you can run it with `./regen.sh`. If you would like the migrations to automatically run after regeneration, add the `-m` flag: `./regen.sh -m`.
-
-## Multiple Repos
-
-If you are using multiple repos, you will likely need to use `mix ecto.migrate` and manage it separately for each repo, as the options would
-be applied to both repo, which wouldn't make sense.
+After saving this file to something like `regen.sh`, make it executable with `chmod +x regen.sh`. Now you can run it with `./regen.sh name_of_operation`. If you would like the migrations to automatically run after regeneration, add the `-m` flag: `./regen.sh name_of_operation -m`.
 
 ## Running Migrations in Production
 
@@ -164,3 +146,11 @@ Tasks that need to be executed in the released application (because mix is not p
   end
 end
 ```
+
+### AshPostgres-specific mix tasks
+
+- `mix ash_postgres.generate_migrations`
+- `mix ash_postgres.create`
+- `mix ash_postgres.drop`
+- `mix ash_postgres.migrate` (use `mix ash_postgres.migrate --tenants` to run tenant migrations)
+- `mix ash_postgres.rollback` (use `mix ash_postgres.rollback --tenants` to rollback tenant migrations)

lib/data_layer.ex

@@ -420,15 +420,18 @@ defmodule AshPostgres.DataLayer do
         |> Enum.map(fn {file, index} -> "#{index + 1}: #{file}" end)
 
       n =
-        Mix.shell().prompt("""
-        How many migrations should be rolled back#{for_repo}? (default: 0)
+        Mix.shell().prompt(
+          """
+          How many migrations should be rolled back#{for_repo}? (default: 0)
 
-        Last 20 migration names, with the input you must provide to
-        rollback up to *and including* that migration:
+          Last 20 migration names, with the input you must provide to
+          rollback up to *and including* that migration:
 
-        #{Enum.join(files, "\n")}
-        Rollback to:
-        """ |> String.trim_trailing())
+          #{Enum.join(files, "\n")}
+          Rollback to:
+          """
+          |> String.trim_trailing()
+        )
         |> String.trim()
         |> case do
           "" ->
@@ -484,7 +487,11 @@ defmodule AshPostgres.DataLayer do
               end
           end
 
-        Mix.Task.run("ash_postgres.rollback", args ++ ["--tenants", "-r", inspect(repo), "-n", to_string(n)])
+        Mix.Task.run(
+          "ash_postgres.rollback",
+          args ++ ["--tenants", "-r", inspect(repo), "-n", to_string(n)]
+        )
+
         Mix.Task.reenable("ash_postgres.rollback")
       end
     end
@@ -507,7 +514,23 @@ defmodule AshPostgres.DataLayer do
     # TODO: take args that we care about
     Mix.Task.run("ash_postgres.create", args)
     Mix.Task.run("ash_postgres.migrate", args)
-    Mix.Task.run("ash_postgres.migrate", ["--tenant" | args])
+
+    []
+    |> AshPostgres.Mix.Helpers.repos!(args)
+    |> Enum.all?(fn repo ->
+      []
+      |> AshPostgres.Mix.Helpers.tenant_migrations_path(repo)
+      |> Path.join("**/*.exs")
+      |> Path.wildcard()
+      |> Enum.empty?()
+    end)
+    |> case do
+      true ->
+        :ok
+
+      _ ->
+        Mix.Task.run("ash_postgres.migrate", ["--tenant" | args])
+    end
   end
 
   def tear_down(args) do