fix: find clashing linter names when part of merged linter

harper-core/src/linting/expr_linter.rs

@@ -113,6 +113,10 @@ where
     fn description(&self) -> &str {
         self.description()
     }
+
+    fn merged_linter_child_names(&self) -> Vec<&'static str> {
+        vec![]
+    }
 }
 
 pub fn run_on_chunk<'a>(

harper-core/src/linting/lint_group/mod.rs

@@ -332,21 +332,61 @@ impl LintGroup {
             || self.sentence_expr_linters.contains_key(name.as_ref())
     }
 
+    /// Check for clashes between a new linter and existing linters
+    /// Returns detailed clash information with counts for debugging
+    fn check_clashes(&self, name: &str, child_names: &[&str]) -> Option<Vec<String>> {
+        use hashbrown::HashMap;
+        let mut clash_counts = HashMap::new();
+
+        // Check direct name clash with existing `Linter`s or `ExprLinter`s
+        if self.contains_key(name) {
+            *clash_counts.entry(name.to_string()).or_insert(0) += 1;
+        }
+
+        // Check if new linter's name clashes with child names of existing linters
+        for existing_linter in self.linters.values() {
+            if existing_linter.merged_linter_child_names().contains(&name) {
+                *clash_counts.entry(name.to_string()).or_insert(0) += 1;
+            }
+        }
+
+        // Check if child names clash with existing linters
+        for &child_name in child_names {
+            if self.contains_key(child_name) {
+                *clash_counts.entry(child_name.to_string()).or_insert(0) += 1;
+            }
+        }
+
+        if clash_counts.is_empty() {
+            None
+        } else {
+            Some(
+                clash_counts
+                    .into_iter()
+                    .map(|(name, count)| format!("{name} (used {} times)", count + 1))
+                    .collect(),
+            )
+        }
+    }
+
     /// Add a [`Linter`] to the group, returning whether the operation was successful.
     /// If it returns `false`, it is because a linter with that key already existed in the group.
     pub fn add(&mut self, name: impl AsRef<str>, linter: impl Linter + 'static) -> bool {
-        if self.contains_key(&name) {
+        let name_str = name.as_ref();
+        let child_names = linter.merged_linter_child_names();
+
+        if let Some(clashes) = self.check_clashes(name_str, &child_names) {
             if self.clashing_linter_names.is_none() {
-                self.clashing_linter_names = Some(vec![name.as_ref().to_string()]);
+                self.clashing_linter_names = Some(clashes);
             } else if let Some(clashing_names) = &mut self.clashing_linter_names {
-                clashing_names.push(name.as_ref().to_string());
+                clashing_names.extend(clashes);
             }
-            false
-        } else {
-            self.linters
-                .insert(name.as_ref().to_string(), Box::new(linter));
-            true
+            return false;
         }
+
+        // No clashes found, add the linter
+        self.linters.insert(name_str.to_string(), Box::new(linter));
+        true
     }
 
     /// Add a chunk-based [`ExprLinter`] to the group, returning whether the operation was successful.
@@ -359,18 +399,22 @@ impl LintGroup {
         name: impl AsRef<str>,
         linter: impl ExprLinter<Unit = Chunk> + 'static,
     ) -> bool {
-        if self.contains_key(&name) {
+        let name_str = name.as_ref();
+        let child_names = linter.merged_linter_child_names();
+
+        if let Some(clashes) = self.check_clashes(name_str, &child_names) {
             if self.clashing_linter_names.is_none() {
-                self.clashing_linter_names = Some(vec![name.as_ref().to_string()]);
+                self.clashing_linter_names = Some(clashes);
             } else if let Some(clashing_names) = &mut self.clashing_linter_names {
-                clashing_names.push(name.as_ref().to_string());
+                clashing_names.extend(clashes);
             }
-            false
-        } else {
-            self.chunk_expr_linters
-                .insert(name.as_ref().to_string(), Box::new(linter) as _);
-            true
+            return false;
         }
+
+        // No clashes found, add the linter
+        self.chunk_expr_linters
+            .insert(name_str.to_string(), Box::new(linter) as _);
+        true
     }
 
     /// Add a sentence-based [`ExprLinter`] to the group, returning whether the operation was successful.
@@ -1180,8 +1224,9 @@ mod tests {
         if let Some(names) = &group.clashing_linter_names {
             if !names.is_empty() {
                 panic!(
-                    "⚠️ Found {} clashing linter names: {}",
+                    "⚠️ Found {} linter name clash{}: {}",
                     names.len(),
+                    if names.len() == 1 { "" } else { "es" },
                     names.join(", ")
                 );
             }

harper-core/src/linting/lint_group/structured_config/mod.rs

@@ -331,7 +331,7 @@ mod tests {
 
         assert!(
             missing_from_default_config.is_empty() && extra_in_default_config.is_empty(),
-            "default_config.json drifted from the registered rule set\nmissing from default_config.json: {:?}\nextra in default_config.json: {:?}\nDid you forget to add the missing rule(s) to default_config.json?",
+            "⚠️ default_config.json drifted from the registered rule set\nmissing from default_config.json: {:?}\nextra in default_config.json: {:?}\nDid you forget to add the missing rule(s) to default_config.json?\nOr are there any clashing linter names?",
             missing_from_default_config,
             extra_in_default_config,
         );

harper-core/src/linting/merge_linters.rs

@@ -34,6 +34,17 @@ macro_rules! merge_linters {
                     fn description(&self) -> &'static str {
                         $desc
                     }
+
+                    fn merged_linter_child_names(&self) -> Vec<&'static str> {
+                        let mut names = Vec::new();
+
+                        $(
+                            names.push(stringify!($linter));
+                            names.extend(self.[< $linter:snake >].merged_linter_child_names());
+                        )*
+
+                        names
+                    }
                 }
             }
         }

harper-core/src/linting/mod.rs

@@ -306,6 +306,14 @@ pub trait Linter: LSend {
     /// A user-facing description of what kinds of grammatical errors this rule looks for.
     /// It is usually shown in settings menus.
     fn description(&self) -> &str;
+
+    /// Get the names of all component linters.
+    /// For merged linters, this includes children, grandchildren, etc.
+    /// Non-merged linters should return an empty array.
+    /// This is used by LintGroup to detect name conflicts.
+    fn merged_linter_child_names(&self) -> Vec<&'static str> {
+        vec![]
+    }
 }
 
 /// A blanket-implemented trait that renders the Markdown description field of a linter to HTML.