perf(linter): improve noImportCycles performance (#7454)

arendjr · web-flow · commit ac171839a316 · 2025-09-09T19:07:34.000+02:00
diff --git a/.changeset/cynical-cyclops-cycles.md b/.changeset/cynical-cyclops-cycles.md
@@ -0,0 +1,7 @@
+---
+"@biomejs/biome": patch
+---
+
+Greatly improved performance of `noImportCycles` by eliminating allocations.
+
+In one repository, the total runtime of Biome with only `noImportCycles` enabled went from ~23s down to ~4s.
diff --git a/crates/biome_js_analyze/src/lint/nursery/no_import_cycles.rs b/crates/biome_js_analyze/src/lint/nursery/no_import_cycles.rs
@@ -6,6 +6,7 @@ use biome_console::markup;
 use biome_diagnostics::Severity;
 use biome_js_syntax::AnyJsImportLike;
 use biome_module_graph::{JsImportPath, JsImportPhase, JsModuleInfo};
+use biome_resolver::ResolvedPath;
 use biome_rowan::AstNode;
 use biome_rule_options::no_import_cycles::NoImportCyclesOptions;
 use camino::{Utf8Path, Utf8PathBuf};
@@ -154,7 +155,7 @@ declare_lint_rule! {
 
 impl Rule for NoImportCycles {
     type Query = ResolvedImports<AnyJsImportLike>;
-    type State = Box<[Box<str>]>;
+    type State = Vec<String>;
     type Signals = Option<Self::State>;
     type Options = NoImportCyclesOptions;
 
@@ -227,10 +228,10 @@ fn find_cycle(
     ctx: &RuleContext<NoImportCycles>,
     start_path: &Utf8Path,
     mut module_info: JsModuleInfo,
-) -> Option<Box<[Box<str>]>> {
+) -> Option<Vec<String>> {
     let options = ctx.options();
     let mut seen = FxHashSet::default();
-    let mut stack: Vec<(Box<str>, JsModuleInfo)> = Vec::new();
+    let mut stack: Vec<(ResolvedPath, JsModuleInfo)> = Vec::new();
 
     'outer: loop {
         for JsImportPath {
@@ -252,17 +253,21 @@ fn find_cycle(
 
             if path == ctx.file_path() {
                 // Return all the paths from `start_path` to `resolved_path`:
-                let paths = Some(start_path.as_str())
+                let paths = Some(start_path.to_string())
                     .into_iter()
-                    .map(Box::from)
-                    .chain(stack.into_iter().map(|(path, _)| path))
-                    .chain(Some(Box::from(path.as_str())))
+                    .chain(
+                        stack
+                            .iter()
+                            .filter_map(|(path, _)| path.as_path())
+                            .map(ToString::to_string),
+                    )
+                    .chain(Some(path.to_string()))
                     .collect();
                 return Some(paths);
             }
 
             if let Some(next_module_info) = ctx.module_info_for_path(path) {
-                stack.push((path.as_str().into(), module_info));
+                stack.push((resolved_path.clone(), module_info));
                 module_info = next_module_info;
                 continue 'outer;
             }
