feat: implement resolver caching improvements

Author: kuoruan

package.json

@@ -11,7 +11,13 @@
     "types": "./lib/index.d.ts"
   },
   "description": "The next resolver for `eslint-plugin-import` or `eslint-plugin-import-x`",
-  "keywords": ["eslint", "eslint-plugin-import", "eslint-plugin-import-x", "eslint-import-resolver", "oxc-resolver"],
+  "keywords": [
+    "eslint",
+    "eslint-plugin-import",
+    "eslint-plugin-import-x",
+    "eslint-import-resolver",
+    "oxc-resolver"
+  ],
   "repository": "https://github.com/kuoruan/eslint-import-resolver-next",
   "license": "MIT",
   "files": [
@@ -30,7 +36,8 @@
   "dependencies": {
     "fast-glob": "^3.3.2",
     "js-yaml": "^4.1.0",
-    "oxc-resolver": "^2.0.1"
+    "oxc-resolver": "^2.0.1",
+    "stable-hash": "^0.0.4"
   },
   "devDependencies": {
     "@babel/eslint-parser": "^7.24.7",

pnpm-lock.yaml

@@ -13,6 +13,7 @@ import {
   cleanModulePath,
   findClosestPackageRoot,
   findPackages,
+  hashObject,
   normalizeAlias,
   normalizeConfigFileOptions,
   normalizePackageGlobOptions,
@@ -52,7 +53,8 @@ function resolveRelativePath(
 }
 
 const pathToPackagesMap = new Map<string, string[]>();
-let resolver: ResolverFactory | null = null;
+
+const resolverCache = new Map<string, ResolverFactory>();
 
 export default function resolve(
   modulePath: string,
@@ -138,24 +140,24 @@ export default function resolve(
     }
   }
 
-  if (!resolver) {
-    resolver = new ResolverFactory({
-      alias: resolveAlias,
-      tsconfig: configFileOptions,
-      roots: resolveRoots,
-      ...restOptions,
-    });
-  } else {
-    const oldResolver = resolver;
+  const specificOptions = {
+    alias: resolveAlias,
+    tsconfig: configFileOptions,
+    roots: resolveRoots,
+  } as const;
+
+  const hashKey = hashObject(specificOptions);
 
-    resolver = oldResolver.cloneWithOptions({
-      alias: resolveAlias,
-      tsconfig: configFileOptions,
-      roots: resolveRoots,
+  let resolver: ResolverFactory;
+  if (resolverCache.has(hashKey)) {
+    resolver = resolverCache.get(hashKey)!;
+  } else {
+    resolver = new ResolverFactory({
+      ...specificOptions,
       ...restOptions,
     });
 
-    oldResolver.clearCache();
+    resolverCache.set(hashKey, resolver);
   }
 
   const result = resolver.sync(path.dirname(sourceFile), modulePath);

src/resolve.ts

@@ -1,7 +1,9 @@
+import crypto from "crypto";
 import fastGlob from "fast-glob";
 import fs from "fs";
 import yaml from "js-yaml";
 import path from "path";
+import stableHash from "stable-hash";
 
 import {
   defaultConfigFileOptions,
@@ -146,6 +148,12 @@ export function sortPaths(paths: string[]): string[] {
   });
 }
 
+/**
+ * Read a yaml file.
+ *
+ * @param filePath {string} - the file path to read
+ * @returns {T | null} - the parsed yaml file
+ */
 export function readYamlFile<T>(filePath: string): T | null {
   if (!fs.existsSync(filePath)) {
     return null;
@@ -161,6 +169,13 @@ export function readYamlFile<T>(filePath: string): T | null {
   return doc;
 }
 
+/**
+ * Normalize package glob options.
+ *
+ * @param opts {PackageOptions | string[]} - the package options
+ * @param root {string} - the root path
+ * @returns {PackageGlobOptions} - the normalized package glob options
+ */
 export function normalizePackageGlobOptions(
   opts: PackageOptions | string[],
   root: string,
@@ -201,6 +216,13 @@ export function normalizePackageGlobOptions(
   };
 }
 
+/**
+ * Find the closest package from the source file.
+ *
+ * @param sourceFile {string} - the source file
+ * @param paths {string[]} - the paths to search
+ * @returns {string | undefined} - the closest package root
+ */
 export function findClosestPackageRoot(
   sourceFile: string,
   paths: string[],
@@ -291,3 +313,13 @@ export function normalizeAlias(
     {} as Record<string, string[]>,
   );
 }
+
+/**
+ * Get the hash of an object.
+ *
+ * @param obj {unknown} - the object to hash
+ * @returns - the hash of the object
+ */
+export function hashObject(obj: unknown): string {
+  return crypto.createHash("sha256").update(stableHash(obj)).digest("hex");
+}