Add the "nil" type

Closes dashbitco#108.
starbelly · Feb 17, 2023 · 5a0b0a9 · 5a0b0a9
1 parent be87ca1
commit 5a0b0a9
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Showing 3 changed files with 40 additions and 7 deletions.
diff --git a/lib/nimble_options.ex b/lib/nimble_options.ex
@@ -122,6 +122,8 @@ defmodule NimbleOptions do
 
     * `:reference` - A reference (see `t:reference/0`).
 
+    * `nil` - The value `nil` itself. Available since v0.6.0.
+
     * `:mfa` - A named function in the format `{module, function, arity}` where
       `arity` is a list of arguments. For example, `{MyModule, :my_fun, [arg1, arg2]}`.
 
@@ -169,7 +171,7 @@ defmodule NimbleOptions do
       same position. For example, to describe 3-element tuples with an atom, a string, and
       a list of integers you would use the type `{:tuple, [:atom, :string, {:list, :integer}]}`.
       *Available since v0.4.1*.
-      
+
     * `{:struct, struct_name}` - An instance of the struct type given.
 
   ## Example
@@ -285,7 +287,8 @@ defmodule NimbleOptions do
     :boolean,
     :timeout,
     :pid,
-    :reference
+    :reference,
+    nil
   ]
 
   @typedoc """
@@ -763,6 +766,18 @@ defmodule NimbleOptions do
     end
   end
 
+  defp validate_type(nil, key, value) do
+    if is_nil(value) do
+      {:ok, value}
+    else
+      error_tuple(
+        key,
+        value,
+        "invalid value for #{render_key(key)}: expected nil, got: #{inspect(value)}"
+      )
+    end
+  end
+
   defp validate_type({:custom, mod, fun, args}, key, value) do
     case apply(mod, fun, [value | args]) do
       {:ok, value} ->
@@ -927,10 +942,6 @@ defmodule NimbleOptions do
     end
   end
 
-  defp validate_type(nil, key, value) do
-    validate_type(:any, key, value)
-  end
-
   defp validate_type(_type, _key, value) do
     {:ok, value}
   end

diff --git a/lib/nimble_options/docs.ex b/lib/nimble_options/docs.ex
@@ -229,6 +229,9 @@ defmodule NimbleOptions.Docs do
       {:non_empty_keyword_list, _keys} ->
         quote(do: keyword())
 
+      nil ->
+        quote(do: nil)
+
       :map ->
         quote(do: map())
 

diff --git a/test/nimble_options_test.exs b/test/nimble_options_test.exs
@@ -41,7 +41,7 @@ defmodule NimbleOptionsTest do
 
       Available types: :any, :keyword_list, :non_empty_keyword_list, :map, :atom, \
       :integer, :non_neg_integer, :pos_integer, :float, :mfa, :mod_arg, :string, :boolean, :timeout, \
-      :pid, :reference, {:fun, arity}, {:in, choices}, {:or, subtypes}, {:custom, mod, fun, args}, \
+      :pid, :reference, nil, {:fun, arity}, {:in, choices}, {:or, subtypes}, {:custom, mod, fun, args}, \
       {:list, subtype}, {:tuple, list_of_subtypes}, {:map, key_type, value_type}, {:struct, struct_name} \
       (in options [:stages])\
       """
@@ -597,6 +597,25 @@ defmodule NimbleOptionsTest do
              }
     end
 
+    test "valid nil" do
+      schema = [name: [type: nil, required: true]]
+      opts = [name: nil]
+      assert NimbleOptions.validate(opts, schema) == {:ok, opts}
+    end
+
+    test "invalid nil" do
+      schema = [name: [type: nil, required: true]]
+      opts = [name: :not_nil]
+
+      assert NimbleOptions.validate(opts, schema) ==
+               {:error,
+                %ValidationError{
+                  key: :name,
+                  value: :not_nil,
+                  message: "invalid value for :name option: expected nil, got: :not_nil"
+                }}
+    end
+
     test "valid {:in, choices}" do
       schema = [batch_mode: [type: {:in, [:flush, :bulk]}]]