From 1e4f683e6ecc040207b87636d16ddbabea10f477 Mon Sep 17 00:00:00 2001
From: camc314 <18101008+camc314@users.noreply.github.com>
Date: Mon, 2 Feb 2026 14:58:46 +0000
Subject: [PATCH] refactor(linter): extract shared config setting logic
 (#18856)

---
 apps/oxlint/src/js_config.rs             | 32 +++-----
 crates/oxc_linter/src/config/oxlintrc.rs | 97 ++++++++++++++++++------
 2 files changed, 84 insertions(+), 45 deletions(-)

diff --git a/apps/oxlint/src/js_config.rs b/apps/oxlint/src/js_config.rs
index 5183b4a8c329c..8cf50cdf4645a 100644
--- a/apps/oxlint/src/js_config.rs
+++ b/apps/oxlint/src/js_config.rs
@@ -106,29 +106,15 @@ fn parse_js_config_response(json: &str) -> Result<Vec<JsConfigResult>, Vec<OxcDi
 
                     oxlintrc.path.clone_from(&path);
 
-                    if let Some(config_dir) = oxlintrc.path.parent() {
-                        if let Some(external_plugins) = &mut oxlintrc.external_plugins {
-                            *external_plugins = std::mem::take(external_plugins)
-                                .into_iter()
-                                .map(|mut entry| {
-                                    entry.config_dir = config_dir.to_path_buf();
-                                    entry
-                                })
-                                .collect();
-                        }
-
-                        for override_config in oxlintrc.overrides.iter_mut() {
-                            if let Some(external_plugins) = &mut override_config.external_plugins {
-                                *external_plugins = std::mem::take(external_plugins)
-                                    .into_iter()
-                                    .map(|mut entry| {
-                                        entry.config_dir = config_dir.to_path_buf();
-                                        entry
-                                    })
-                                    .collect();
-                            }
-                        }
-                    }
+                    let Some(config_dir_parent) = oxlintrc.path.parent() else {
+                        errors.push(OxcDiagnostic::error(format!(
+                            "Config path has no parent directory: {}",
+                            entry.path
+                        )));
+                        return (configs, errors);
+                    };
+                    let config_dir = config_dir_parent.to_path_buf();
+                    oxlintrc.set_config_dir(&config_dir);
                     configs.push(JsConfigResult { path, config: oxlintrc });
 
                     (configs, errors)
diff --git a/crates/oxc_linter/src/config/oxlintrc.rs b/crates/oxc_linter/src/config/oxlintrc.rs
index 8d0610e4ea17f..7e05be107dbf2 100644
--- a/crates/oxc_linter/src/config/oxlintrc.rs
+++ b/crates/oxc_linter/src/config/oxlintrc.rs
@@ -171,28 +171,9 @@ impl Oxlintrc {
         config.path = path.to_path_buf();
 
         #[expect(clippy::missing_panics_doc)]
-        let config_dir = config.path.parent().unwrap();
-        if let Some(external_plugins) = &mut config.external_plugins {
-            *external_plugins = std::mem::take(external_plugins)
-                .into_iter()
-                .map(|mut entry| {
-                    entry.config_dir = config_dir.to_path_buf();
-                    entry
-                })
-                .collect();
-        }
-
-        for override_config in config.overrides.iter_mut() {
-            if let Some(external_plugins) = &mut override_config.external_plugins {
-                *external_plugins = std::mem::take(external_plugins)
-                    .into_iter()
-                    .map(|mut entry| {
-                        entry.config_dir = config_dir.to_path_buf();
-                        entry
-                    })
-                    .collect();
-            }
-        }
+        let config_dir =
+            config.path.parent().expect("config path should have a parent directory").to_path_buf();
+        config.set_config_dir(&config_dir);
 
         Ok(config)
     }
@@ -278,6 +259,34 @@ impl Oxlintrc {
             extends: self.extends.clone(),
         }
     }
+
+    /// Update the configuration directory for all external plugin entries in this config
+    /// and in its overrides. The underlying `HashSet` is rebuilt because `config_dir`
+    /// participates in the `Hash`/`Eq` implementation of each entry, so changing it
+    /// requires rehashing the set.
+    pub fn set_config_dir(&mut self, config_dir: &Path) {
+        if let Some(external_plugins) = &mut self.external_plugins {
+            *external_plugins = std::mem::take(external_plugins)
+                .into_iter()
+                .map(|mut entry| {
+                    entry.config_dir = config_dir.to_path_buf();
+                    entry
+                })
+                .collect();
+        }
+
+        for override_config in self.overrides.iter_mut() {
+            if let Some(external_plugins) = &mut override_config.external_plugins {
+                *external_plugins = std::mem::take(external_plugins)
+                    .into_iter()
+                    .map(|mut entry| {
+                        entry.config_dir = config_dir.to_path_buf();
+                        entry
+                    })
+                    .collect();
+            }
+        }
+    }
 }
 
 fn is_json_ext(ext: &str) -> bool {
@@ -456,4 +465,48 @@ mod test {
         let merged = config1.merge(config2);
         assert_eq!(merged.schema, Some("schema2.json".to_string()));
     }
+
+    #[test]
+    fn test_set_config_dir() {
+        let mut config: Oxlintrc = serde_json::from_str(
+            r#"{
+                "jsPlugins": ["./plugin1.ts", { "name": "custom", "specifier": "./plugin2.ts" }],
+                "overrides": [{ "files": ["*.test.ts"], "jsPlugins": ["./override-plugin.ts"] }]
+            }"#,
+        )
+        .unwrap();
+
+        // Verify initial state - config_dir should be empty PathBuf
+        let top_level_plugins = config.external_plugins.as_ref().unwrap();
+        assert_eq!(top_level_plugins.len(), 2);
+        for entry in top_level_plugins {
+            assert_eq!(entry.config_dir, PathBuf::new());
+        }
+
+        let override_plugins =
+            config.overrides.iter().next().unwrap().external_plugins.as_ref().unwrap();
+        assert_eq!(override_plugins.len(), 1);
+        for entry in override_plugins {
+            assert_eq!(entry.config_dir, PathBuf::new());
+        }
+
+        // Call set_config_dir
+        let new_config_dir = PathBuf::from("/project/config");
+        config.set_config_dir(&new_config_dir);
+
+        // Assert that all top-level plugins have the new config_dir
+        let top_level_plugins = config.external_plugins.as_ref().unwrap();
+        assert_eq!(top_level_plugins.len(), 2);
+        for entry in top_level_plugins {
+            assert_eq!(entry.config_dir, new_config_dir);
+        }
+
+        // Assert that all override plugins have the new config_dir
+        let override_plugins =
+            config.overrides.iter().next().unwrap().external_plugins.as_ref().unwrap();
+        assert_eq!(override_plugins.len(), 1);
+        for entry in override_plugins {
+            assert_eq!(entry.config_dir, new_config_dir);
+        }
+    }
 }