From bca82b2b13ccf3e09dbc9ae6b6e408e12238ef5e Mon Sep 17 00:00:00 2001
From: Roman Heinrich <roman.heinrich@gmail.com>
Date: Wed, 13 Dec 2023 22:12:07 +0100
Subject: [PATCH] Feat: add `upsert` macro

---
 CHANGELOG.md                                  |  4 ++++
 lib/dryhard.ex                                | 22 +++++++++++++++++++
 .../20230320215000_dryhard_migrations.exs     |  1 +
 test/dryhard_test.exs                         |  7 ++++++
 4 files changed, 34 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b23741..e288a6b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v0.1.1 (2023-12-13)
+
+- add new macro: `upsert`. It allows providing `:on_conflict` options, defaults to `[on_conflict: :nothing]`
+
 ## v0.1.0 (2023-11-29)
 
 - mostly working, need a bit polish
diff --git a/lib/dryhard.ex b/lib/dryhard.ex
index f8e8d5f..d4e66bd 100644
--- a/lib/dryhard.ex
+++ b/lib/dryhard.ex
@@ -173,6 +173,28 @@ defmodule Dryhard do
     end
   end
 
+  defmacro upsert(config, changeset_fn, opts \\ [on_conflict: :nothing]) do
+    quote bind_quoted: [config: config, changeset_fn: changeset_fn, opts: opts] do
+      @doc """
+      Creates a single #{config.plural_name} record (ignores conflicts, like ID / uniq indexes)
+      Provide upsert options as documented here:
+        - https://hexdocs.pm/ecto/Ecto.Repo.html#c:insert/2-upserts
+
+      Defaults to:
+        `[on_conflict: :nothing]`
+
+      Params:
+        - attrs: map to pass into the changeset function
+      """
+      def unquote(:"upsert_#{config.singular_name}")(attrs) do
+        unquote(config.schema)
+        |> struct()
+        |> unquote(changeset_fn).(attrs)
+        |> unquote(config.repo).insert(unquote(opts))
+      end
+    end
+  end
+
   defmacro create(config, changeset_fn) do
     quote bind_quoted: [config: config, changeset_fn: changeset_fn] do
       @doc """
diff --git a/priv/repo/migrations/20230320215000_dryhard_migrations.exs b/priv/repo/migrations/20230320215000_dryhard_migrations.exs
index 4c93102..a24e62b 100644
--- a/priv/repo/migrations/20230320215000_dryhard_migrations.exs
+++ b/priv/repo/migrations/20230320215000_dryhard_migrations.exs
@@ -17,6 +17,7 @@ defmodule Dryhard.Repo.Migrations.CreateTables do
 
       timestamps()
     end
+    create unique_index(:users, [:username])
 
     create table(:posts) do
       add :user_id, references(:users)
diff --git a/test/dryhard_test.exs b/test/dryhard_test.exs
index f87f8d2..b6bbc17 100644
--- a/test/dryhard_test.exs
+++ b/test/dryhard_test.exs
@@ -22,6 +22,7 @@ defmodule DryhardTest do
     Dryhard.get(@resource)
     Dryhard.new(@resource)
     Dryhard.create(@resource, &User.changeset/2)
+    Dryhard.upsert(@resource, &User.changeset/2)
     Dryhard.change(@resource, &User.changeset/2)
     Dryhard.update(@resource, &User.changeset/2)
     Dryhard.delete(@resource)
@@ -74,6 +75,12 @@ defmodule DryhardTest do
     assert user1 == UserContext.get_user_by_username("user1")
   end
 
+  test "upsert_user works (ignore conflicts on inserts by default)" do
+    {:ok, user1} = UserContext.upsert_user(%{username: "user1"})
+    {:ok, _user1_duplicate} = UserContext.upsert_user(%{username: "user1"})
+    assert user1 == UserContext.get_user_by_username("user1")
+  end
+
   test "update_user works" do
     {:ok, user1} = UserContext.create_user(%{username: "user1"})
     assert user1 == UserContext.get_user_by_username("user1")