add doc and refactor

lib/container.ex

@@ -87,15 +87,16 @@ defmodule Testcontainers.Container do
   Sets a file or the directory on the _host machine_ to be mounted into a _container_.
   """
   def with_bind_mount(%__MODULE__{} = config, host_src, container_dest, options \\ "ro")
-      when is_binary(host_src) and is_binary(container_dest) do
+      when is_binary(host_src) and is_binary(container_dest) and is_binary(options) do
     new_bind_mount = %{host_src: host_src, container_dest: container_dest, options: options}
     %__MODULE__{config | bind_mounts: [new_bind_mount | config.bind_mounts]}
   end
 
   @doc """
   Sets a volume to be mounted into a container on target path
   """
-  def with_bind_volume(%__MODULE__{} = config, volume, container_dest, read_only \\ false) do
+  def with_bind_volume(%__MODULE__{} = config, volume, container_dest, read_only \\ false)
+      when is_binary(volume) and is_binary(container_dest) and is_boolean(read_only) do
     new_bind_volume = %{
       volume: volume,
       container_dest: container_dest,

lib/container/mysql_container.ex

@@ -194,33 +194,36 @@ defmodule Testcontainers.MySqlContainer do
             "Image #{config.image} is not compatible with #{MySqlContainer.default_image()}"
       end
 
-      port_fn =
-        case config.port do
-          {exposed_port, host_port} ->
-            fn container -> with_fixed_port(container, exposed_port, host_port) end
-
-          port ->
-            fn container -> with_exposed_port(container, port) end
-        end
-
-      maybe_persisntent_volume_fn =
-        case config.persistent_volume do
-          nil -> fn container -> container end
-          volume -> fn container -> container |> with_bind_volume(volume, "/var/lib/mysql") end
-        end
-
       new(config.image)
-      |> Kernel.then(port_fn)
+      |> then(MySqlContainer.container_port_fun(config.port))
       |> with_environment(:MYSQL_USER, config.user)
       |> with_environment(:MYSQL_PASSWORD, config.password)
       |> with_environment(:MYSQL_DATABASE, config.database)
-      |> Kernel.then(maybe_persisntent_volume_fn)
+      |> then(MySqlContainer.container_volume_fun(config.persistent_volume))
       |> with_environment(:MYSQL_RANDOM_ROOT_PASSWORD, "yes")
       |> with_waiting_strategy(
         LogWaitStrategy.new(~r/.*port: 3306  MySQL Community Server.*/, config.wait_timeout)
       )
     end
   end
+
+  @doc false
+  def container_port_fun(nil), do: &Function.identity/1
+
+  def container_port_fun({exposed_port, host_port}) do
+    fn container -> Container.with_fixed_port(container, exposed_port, host_port) end
+  end
+
+  def container_port_fun(port) do
+    fn container -> Container.with_exposed_port(container, port) end
+  end
+
+  @doc false
+  def container_volume_fun(nil), do: &Function.identity/1
+
+  def container_volume_fun(volume) when is_binary(volume) do
+    fn container -> Container.with_bind_volume(container, volume, "/var/lib/mysql") end
+  end
 end
 
 defmodule Testcontainers.Container.MySqlContainer do

lib/container/postgres_container.ex

@@ -194,30 +194,12 @@ defmodule Testcontainers.PostgresContainer do
             "Image #{config.image} is not compatible with #{PostgresContainer.default_image()}"
       end
 
-      port_fn =
-        case config.port do
-          {exposed_port, host_port} ->
-            fn container -> with_fixed_port(container, exposed_port, host_port) end
-
-          port ->
-            fn container -> with_exposed_port(container, port) end
-        end
-
-      maybe_persisntent_volume_fn =
-        case config.persistent_volume do
-          nil ->
-            fn container -> container end
-
-          volume ->
-            fn container -> container |> with_bind_volume(volume, "/var/lib/postgresql/data") end
-        end
-
       new(config.image)
-      |> Kernel.then(port_fn)
+      |> then(PostgresContainer.container_port_fun(config.port))
       |> with_environment(:POSTGRES_USER, config.user)
       |> with_environment(:POSTGRES_PASSWORD, config.password)
       |> with_environment(:POSTGRES_DB, config.database)
-      |> Kernel.then(maybe_persisntent_volume_fn)
+      |> then(PostgresContainer.container_volume_fun(config.persistent_volume))
       |> with_waiting_strategy(
         CommandWaitStrategy.new(
           [
@@ -230,6 +212,24 @@ defmodule Testcontainers.PostgresContainer do
       )
     end
   end
+
+  @doc false
+  def container_port_fun(nil), do: &Function.identity/1
+
+  def container_port_fun({exposed_port, host_port}) do
+    fn container -> Container.with_fixed_port(container, exposed_port, host_port) end
+  end
+
+  def container_port_fun(port) do
+    fn container -> Container.with_exposed_port(container, port) end
+  end
+
+  @doc false
+  def container_volume_fun(nil), do: &Function.identity/1
+
+  def container_volume_fun(volume) when is_binary(volume) do
+    fn container -> Container.with_bind_volume(container, volume, "/var/lib/postgresql/data") end
+  end
 end
 
 defmodule Testcontainers.Container.PostgresContainer do

lib/ecto.ex

@@ -22,6 +22,7 @@ defmodule Testcontainers.Ecto do
     - `:password` (optional) - Determines the password for the Postgres user (defaults to "postgres").
     - `:database` (optional) - Specifies the name of the database to be created within the Postgres instance. If not provided, the default behavior is to create a database with the name derived from the application's atom, appended with "_test".
     - `:migrations_path` (optional) - Indicates the path to the migrations folder (defaults to "priv/repo/migrations").
+    - `:persistent_volume_name` (optional, EXPERIMENTAL) - Sets a named volume for the data in the database. This is an experimental option, and changes in database container image or other things that could invalidate the data, would make the container not start properly.
 
   ## Database Lifecycle in Testing
 
@@ -117,7 +118,7 @@ defmodule Testcontainers.Ecto do
     - `:password` (optional) - Determines the password for the Mysql user (defaults to "test").
     - `:database` (optional) - Specifies the name of the database to be created within the Mysql instance. If not provided, the default behavior is to create a database with the name derived from the application's atom, appended with "_test".
     - `:migrations_path` (optional) - Indicates the path to the migrations folder (defaults to "priv/repo/migrations").
-
+    - `:persistent_volume_name` (optional, EXPERIMENTAL) - Sets a named volume for the data in the database. This is an experimental option, and changes in database container image or other things that could invalidate the data, would make the container not start properly.
   ## Database Lifecycle in Testing
 
   It's important to note that the Mysql database initiated by this function will remain operational for the duration of the test process and is not explicitly shut down by the function. The database and its corresponding data are ephemeral, lasting only for the scope of the test session.