1 files changed, 49 insertions, 0 deletions

diff --git a/lib/src/lints/manual_inherit_from.rs b/lib/src/lints/manual_inherit_from.rs
new file mode 100644
index 0000000..055cba2
--- /dev/null
+++ b/lib/src/lints/manual_inherit_from.rs
@@ -0,0 +1,49 @@
+use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+
+use if_chain::if_chain;
+use macros::lint;
+use rnix::{
+    types::{KeyValue, Ident, Select, TypedNode, TokenWrapper},
+    NodeOrToken, SyntaxElement, SyntaxKind,
+};
+
+#[lint(
+    name = "manual inherit from",
+    note = "Assignment instead of inherit from",
+    code = 4,
+    match_with = SyntaxKind::NODE_KEY_VALUE
+)]
+struct ManualInherit;
+
+impl Rule for ManualInherit {
+    fn validate(&self, node: &SyntaxElement) -> Option<Report> {
+        if_chain! {
+            if let NodeOrToken::Node(key_value_node) = node;
+            if let Some(key_value_stmt) = KeyValue::cast(key_value_node.clone());
+            if let Some(key_path) = key_value_stmt.key();
+            if let Some(key_node) = key_path.path().next();
+            if let Some(key) = Ident::cast(key_node);
+
+            if let Some(value_node) = key_value_stmt.value();
+            if let Some(value) = Select::cast(value_node);
+            if let Some(index_node) = value.index();
+            if let Some(index) = Ident::cast(index_node);
+
+            if key.as_str() == index.as_str();
+
+            then {
+                let at = node.text_range();
+                let replacement = {
+                    let set = value.set()?;
+                    make::inherit_from_stmt(set, &[key]).node().clone() 
+                };
+                let message = format!("The assignment `{}` is better written with `inherit`", node);
+                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+            } else {
+                None
+            }
+        }
+    }
+}
+
+