chore: fix dialyzer issues

apps/app/lib/app/accounts/avatars.ex

@@ -5,6 +5,11 @@ defmodule App.Accounts.Avatars do
   Uses Gravatar as the default avatar provider.
   """
 
+  @type entity() :: %{
+          :email => binary(),
+          optional(atom()) => any()
+        }
+
   @doc """
   Get the avatar URL for an entity. Currently, only entities with an `:email`
   field are supported.
@@ -15,7 +20,7 @@ defmodule App.Accounts.Avatars do
       "https://www.gravatar.com/avatar/7671d949664fc1fbce03b4ee41c509a4"
 
   """
-  @spec avatar_url(%{email: binary()}) :: String.t()
+  @spec avatar_url(entity()) :: String.t()
   def avatar_url(%{email: email}) do
     gravatar_email_url(email)
   end

apps/app/lib/app/balance.ex

@@ -6,6 +6,7 @@ defmodule App.Balance do
   alias App.Repo
 
   alias App.Transfers
+  alias App.Books.BookMember
 
   @doc """
   Compute the `:balance` field of book members.

apps/app/lib/app/balance/balance_config.ex

@@ -126,14 +126,14 @@ defmodule App.Balance.BalanceConfig do
   @type id :: integer()
 
   @type t :: %__MODULE__{
-          id: id(),
+          id: id() | nil,
           annual_income: non_neg_integer() | nil,
-          owner: User.t(),
-          owner_id: User.id(),
-          created_for: :user | :book_member,
-          start_date_of_validity: DateTime.t(),
-          inserted_at: NaiveDateTime.t(),
-          updated_at: NaiveDateTime.t()
+          owner: User.t() | Ecto.Association.NotLoaded.t(),
+          owner_id: User.id() | nil,
+          created_for: :user | :book_member | nil,
+          start_date_of_validity: DateTime.t() | nil,
+          inserted_at: NaiveDateTime.t() | nil,
+          updated_at: NaiveDateTime.t() | nil
         }
 
   @derive {Inspect, only: [:id, :owner, :owner_id]}

apps/app/lib/app/books.ex

@@ -54,7 +54,7 @@ defmodule App.Books do
   end
 
   # Returns a query that fetches all books a user belongs to.
-  @spec books_of_user_query(Auth.User.t()) :: Ecto.Query.t()
+  @spec books_of_user_query(User.t()) :: Ecto.Query.t()
   defp books_of_user_query(%User{} = user) do
     from [book: book] in Book.base_query(),
       join: member in BookMember,

apps/app/lib/app/books/book.ex

@@ -13,7 +13,7 @@ defmodule App.Books.Book do
   @type t :: %__MODULE__{
           id: id(),
           name: String.t(),
-          closed_at: NaiveDateTime.t(),
+          closed_at: NaiveDateTime.t() | nil,
           deleted_at: NaiveDateTime.t(),
           default_balance_params: TransferParams.t(),
           inserted_at: NaiveDateTime.t(),

apps/app/lib/app/books/book_member.ex

@@ -14,21 +14,21 @@ defmodule App.Books.BookMember do
   @type id :: integer()
 
   @type t :: %__MODULE__{
-          id: id(),
-          book_id: Book.id(),
-          book: Book.t(),
-          role: :creator | :member,
-          user_id: User.id() | nil,
-          user: User.t() | nil,
-          deleted_at: NaiveDateTime.t(),
-          nickname: String.t(),
+          id: id() | nil,
+          book_id: Book.id() | nil,
+          book: Book.t() | Ecto.Association.NotLoaded.t(),
+          role: :creator | :member | nil,
+          user_id: User.id() | Ecto.Association.NotLoaded.t() | nil,
+          user: User.t() | Ecto.Association.NotLoaded.t() | nil,
+          deleted_at: NaiveDateTime.t() | nil,
+          nickname: String.t() | nil,
           display_name: String.t() | nil,
           email: String.t() | nil,
-          balance_config: BalanceConfig.t() | nil,
           balance_config_id: BalanceConfig.id() | nil,
+          balance_config: BalanceConfig.t() | Ecto.Association.NotLoaded.t() | nil,
           balance: Money.t() | {:error, reasons :: [String.t()]} | nil,
-          inserted_at: NaiveDateTime.t(),
-          updated_at: NaiveDateTime.t()
+          inserted_at: NaiveDateTime.t() | nil,
+          updated_at: NaiveDateTime.t() | nil
         }
 
   schema "book_members" do

apps/app/lib/app/books/members.ex

@@ -128,7 +128,7 @@ defmodule App.Books.Members do
   @doc """
   Link an existing book member to a user.
   """
-  @spec link_book_member_to_user(BookMember.t(), User.t()) :: BookMember.t()
+  @spec link_book_member_to_user(BookMember.t(), User.t()) :: :ok
   def link_book_member_to_user(book_member, user) do
     {:ok, _results} =
       Ecto.Multi.new()