feat: cache realpath and realpathSync methods

Author: alexander-akait

lib/CachedInputFileSystem.js

@@ -577,6 +577,19 @@ module.exports = class CachedInputFileSystem {
 		this.readlinkSync = /** @type {SyncFileSystem["readlinkSync"]} */ (
 			readlinkSync
 		);
+
+		this._realpathBackend = createBackend(
+			duration,
+			this.fileSystem.realpath,
+			this.fileSystem.realpath,
+			this.fileSystem
+		);
+		const realpath = this._realpathBackend.provide;
+		this.realpath = /** @type {FileSystem["realpath"]} */ (realpath);
+		const realpathSync = this._realpathBackend.provideSync;
+		this.realpathSync = /** @type {SyncFileSystem["realpathSync"]} */ (
+			realpathSync
+		);
 	}
 
 	/**
@@ -589,5 +602,6 @@ module.exports = class CachedInputFileSystem {
 		this._readFileBackend.purge(what);
 		this._readlinkBackend.purge(what);
 		this._readJsonBackend.purge(what);
+		this._realpathBackend.purge(what);
 	}
 };

lib/Resolver.js

@@ -65,6 +65,7 @@ const {
  * @property {(function(string, FileSystemCallback<Buffer | string>): void) & function(string, object, FileSystemCallback<Buffer | string>): void} readlink
  * @property {(function(string, FileSystemCallback<FileSystemStats>): void) & function(string, object, FileSystemCallback<Buffer | string>): void=} lstat
  * @property {(function(string, FileSystemCallback<FileSystemStats>): void) & function(string, object, FileSystemCallback<Buffer | string>): void} stat
+ * @property {(function(string, FileSystemCallback<FileSystemStats>): void) & function(string, object, FileSystemCallback<Buffer | string>): void} realpath
  */
 
 /**
@@ -75,6 +76,7 @@ const {
  * @property {function(string, object=): Buffer | string} readlinkSync
  * @property {function(string, object=): FileSystemStats=} lstatSync
  * @property {function(string, object=): FileSystemStats} statSync
+ * @property {function(string, object=): string | Buffer} realpathSync
  */
 
 /**