Add non-exhaustive Debug output for structs

Author: daxpedda

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Updated `syn` to v2.
+- `Debug` output of structs that skip fields appears `non_exhaustive` now.
 
 ### Deprecated
 - The `crate` attribute now takes a path instead of a path inside a string

Cargo.toml

@@ -43,11 +43,6 @@ pretty_assertions = "1"
 trybuild = { version = "1.0.18", default-features = false }
 zeroize_ = { version = "1.5", package = "zeroize", default-features = false }
 
-[[test]]
-name = "util"
-path = "tests/util.rs"
-test = false
-
 [package.metadata.docs.rs]
 all-features = true
 targets = []

src/trait_/debug.rs

@@ -50,11 +50,17 @@ impl TraitImpl for Debug {
 					.iter_field_ident(**trait_)
 					.map(|field| field.to_string());
 
+				let finish = if data.any_skip_trait(**trait_) {
+					quote! { finish_non_exhaustive }
+				} else {
+					quote! { finish }
+				};
+
 				quote! {
 					#self_pattern => {
 						let mut __builder = ::core::fmt::Formatter::debug_struct(__f, #debug_name);
 						#(::core::fmt::DebugStruct::field(&mut __builder, #debug_fields, #self_ident);)*
-						::core::fmt::DebugStruct::finish(&mut __builder)
+						::core::fmt::DebugStruct::#finish(&mut __builder)
 					}
 				}
 			}

tests/skip.rs

@@ -1,9 +1,9 @@
 #![allow(clippy::clone_on_copy)]
 
-// Necessary for rustfmt.
-#[path = "util.rs"]
 #[macro_use]
 mod util;
+#[path = "skip/debug.rs"]
+mod debug;
 #[path = "skip/field.rs"]
 mod field;
 #[path = "skip/field_trait.rs"]

tests/skip/debug.rs

@@ -0,0 +1,37 @@
+use derive_where::derive_where;
+
+use crate::util::{AssertDebug, Wrapper};
+
+#[test]
+fn all() {
+	#[derive_where(Debug)]
+	#[derive_where(skip_inner)]
+	struct Test<T> {
+		a: Wrapper<T>,
+	}
+
+	let test_1 = Test { a: 42.into() };
+
+	let _ = AssertDebug(&test_1);
+
+	assert_eq!(format!("{:?}", test_1), "Test { .. }");
+}
+
+#[test]
+fn partial() {
+	#[derive_where(Debug)]
+	struct Test<T> {
+		#[derive_where(skip)]
+		a: Wrapper<T>,
+		b: Wrapper<T>,
+	}
+
+	let test_1 = Test {
+		a: 42.into(),
+		b: 42.into(),
+	};
+
+	let _ = AssertDebug(&test_1);
+
+	assert_eq!(format!("{:?}", test_1), "Test { b: 42, .. }");
+}