perf(linter): avoid iteration when checking import is AllButDefault or SideEffect in eslint/no-duplicate-imports (#12093)

Sysix · Sysix · commit 04e2de52d817 · 2025-07-06T13:09:02.000Z
Avoid the 3 iterations

```
    let namespace = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Namespace));
    let named = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Named));
    let default = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Default));
```

when the `ImportType` is `SideEffect` or `AllButDefault`. Their results are not needed for the two types.
diff --git a/crates/oxc_linter/src/rules/eslint/no_duplicate_imports.rs b/crates/oxc_linter/src/rules/eslint/no_duplicate_imports.rs
@@ -303,6 +303,14 @@ fn can_merge_imports(
     current_type: &ImportType,
     existing: &[(ImportType, Span, ModuleType)],
 ) -> bool {
+    if *current_type == ImportType::AllButDefault {
+        return false;
+    }
+
+    if *current_type == ImportType::SideEffect {
+        return !existing.is_empty();
+    }
+
     let namespace = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Namespace));
     let named = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Named));
     let default = existing.iter().find(|(t, _, _)| matches!(t, ImportType::Default));
@@ -333,8 +341,7 @@ fn can_merge_imports(
             has_namespace || has_default
         }
         ImportType::Default => has_default || has_namespace || has_named,
-        ImportType::SideEffect => !existing.is_empty(),
-        ImportType::AllButDefault => false,
+        _ => unreachable!("other ImportType values should be already checked"),
     }
 }
 
