Merge pull request #2 from N4D1K-lgtm/dev

fix: Corrected derived `From` implementation

README.md

@@ -141,9 +141,8 @@ assert!(settings.debug)
 - The `prefix` is applied per field or for the entire struct, but is ignored if `#[config(key = "_")]` is used.
 - All configuration structs must implement [`Default`](https://doc.rust-lang.org/std/default/trait.Default.html).
 - Custom types used in configuration struct fields must implement [`Deserialize`](https://docs.rs/serde/latest/serde/trait.Deserialize.html),
-  [`Clone`](https://doc.rust-lang.org/std/clone/trait.Clone.html),
-  [`Debug`](https://doc.rust-lang.org/std/fmt/trait.Debug.html) and
-  [`Default`](https://doc.rust-lang.org/std/default/trait.Default.html).
+  [`Clone`](https://doc.rust-lang.org/std/clone/trait.Clone.html), and
+  [`Debug`](https://doc.rust-lang.org/std/fmt/trait.Debug.html).
 - [`Option`](https://doc.rust-lang.org/std/option/enum.Option.html) is not currently compatible with `#[config(nest)]`
   on types that implement [`Confgr`](https://docs.rs/confgr/latest/confgr/core/trait.Confgr.html).
 

crates/confgr_derive/src/convert.rs

@@ -22,7 +22,7 @@ pub fn generate_conversion_impl(
             }
         } else {
             quote! {
-                #field_name: #LAYER_PARAMETER.#field_name.unwrap_or_default(),
+                #field_name: #LAYER_PARAMETER.#field_name.unwrap_or_else(|| #name::default().#field_name),
             }
         }
     });

crates/confgr_derive/src/merge.rs

@@ -67,7 +67,7 @@ pub fn generate_layer(
         #[automatically_derived]
         impl Default for #layer_name {
            fn default() -> Self {
-            #name::default().into()
+                #name::default().into()
             }
         }
 

tests/foreign.rs

@@ -0,0 +1,33 @@
+use confgr::prelude::*;
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize, Clone)]
+struct NonDefaultType {
+    value: String,
+}
+
+fn default_non_default_type() -> NonDefaultType {
+    NonDefaultType {
+        value: "default_value".to_string(),
+    }
+}
+
+#[derive(Config)]
+struct TestConfig {
+    #[config(skip)]
+    foreign_type: NonDefaultType,
+}
+
+impl Default for TestConfig {
+    fn default() -> Self {
+        Self {
+            foreign_type: default_non_default_type(),
+        }
+    }
+}
+
+#[test]
+fn test_non_default_foreign_type_is_valid() {
+    let config = TestConfig::load_config();
+    assert_eq!(config.foreign_type.value, "default_value");
+}