test: update tests, add eslint rules

tests/helpers/InMemoryFileSystem.ts

@@ -1,14 +1,14 @@
 import { IFileSystem } from "@/ports";
 
 export class InMemoryFileSystem implements IFileSystem {
-	private files = new Map<string, string>();
+	#files = new Map<string, string>();
 
 	reset(): void {
-		this.files.clear();
+		this.#files.clear();
 	}
 
 	async readFile(path: string): Promise<string> {
-		const content = this.files.get(path);
+		const content = this.#files.get(path);
 		if (content === undefined) {
 			throw new Error(`ENOENT: no such file: ${path}`);
 		}
@@ -16,17 +16,17 @@ export class InMemoryFileSystem implements IFileSystem {
 	}
 
 	async writeFile(path: string, content: string): Promise<void> {
-		this.files.set(path, content);
+		this.#files.set(path, content);
 	}
 
 	async deleteFile(path: string): Promise<void> {
-		this.files.delete(path);
+		this.#files.delete(path);
 	}
 
 	async readdir(path: string): Promise<string[]> {
 		const prefix = path.endsWith("/") || path.endsWith("\\") ? path : path + "/";
 		const seen = new Set<string>();
-		for (const key of this.files.keys()) {
+		for (const key of this.#files.keys()) {
 			if (key.startsWith(prefix)) {
 				const relative = key.slice(prefix.length);
 				const top = relative.split(/[/\\]/)[0];