[Refactor] no-cycle: Add caching of traversed paths to no-cycle

- This leads to about a 5x speed up

Signed-off-by: Sebastian Malton <sebastian@malton.name>

CHANGELOG.md

@@ -20,12 +20,13 @@ This change log adheres to standards from [Keep a CHANGELOG](https://keepachange
 - [`order`]: leave more space in rankings for consecutive path groups ([#2506], thanks [@Pearce-Ropion])
 
 ### Changed
-- [Tests] `named`: Run all TypeScript test ([#2427], thanks [@ProdigySim])
+- [Tests] [`named`]: Run all TypeScript test ([#2427], thanks [@ProdigySim])
 - [readme] note use of typescript in readme `import/extensions` section ([#2440], thanks [@OutdatedVersion])
-- [Docs] `order`: use correct default value ([#2392], thanks [@hyperupcall])
+- [Docs] [`order`]: use correct default value ([#2392], thanks [@hyperupcall])
 - [meta] replace git.io link in comments with the original URL ([#2444], thanks [@liby])
 - [Docs] remove global install in readme ([#2412], thanks [@aladdin-add])
 - [readme] clarify `eslint-import-resolver-typescript` usage ([#2503], thanks [@JounQin])
+- [Refactor] [`no-cycle`]: Improve performance by using caching ([#2419], thanks [@nokel81])
 
 ## [2.26.0] - 2022-04-05
 
@@ -1004,6 +1005,7 @@ for info on changes for earlier releases.
 [#2466]: https://github.com/import-js/eslint-plugin-import/pull/2466
 [#2440]: https://github.com/import-js/eslint-plugin-import/pull/2440
 [#2427]: https://github.com/import-js/eslint-plugin-import/pull/2427
+[#2419]: https://github.com/import-js/eslint-plugin-import/pull/2419
 [#2417]: https://github.com/import-js/eslint-plugin-import/pull/2417
 [#2411]: https://github.com/import-js/eslint-plugin-import/pull/2411
 [#2399]: https://github.com/import-js/eslint-plugin-import/pull/2399

src/rules/no-cycle.js

@@ -9,6 +9,8 @@ import { isExternalModule } from '../core/importType';
 import moduleVisitor, { makeOptionsSchema } from 'eslint-module-utils/moduleVisitor';
 import docsUrl from '../docsUrl';
 
+const traversed = new Set();
+
 // todo: cache cycles / deep relationships for faster repeat evaluation
 module.exports = {
   meta: {
@@ -40,8 +42,8 @@ module.exports = {
       },
     })],
   },
-
-  create(context) {
+  _traversed: traversed,
+  create: (context) => {
     const myPath = context.getPhysicalFilename ? context.getPhysicalFilename() : context.getFilename();
     if (myPath === '<text>') return {}; // can't cycle-check a non-file
 
@@ -87,7 +89,6 @@ module.exports = {
       }
 
       const untraversed = [{ mget: () => imported, route:[] }];
-      const traversed = new Set();
       function detectCycle({ mget, route }) {
         const m = mget();
         if (m == null) return;

tests/src/rules/no-cycle.js

@@ -2,6 +2,7 @@ import { parsers, test as _test, testFilePath, testVersion as _testVersion } fro
 
 import { RuleTester } from 'eslint';
 import flatMap from 'array.prototype.flatmap';
+import { beforeEach } from 'mocha';
 
 const ruleTester = new RuleTester();
 const rule = require('rules/no-cycle');
@@ -17,6 +18,10 @@ const testVersion = (specifier, t) => _testVersion(specifier, () => Object.assig
 
 const testDialects = ['es6'];
 
+beforeEach(() => {
+  rule._traversed.clear();
+});
+
 ruleTester.run('no-cycle', rule, {
   valid: [].concat(
     // this rule doesn't care if the cycle length is 0