Save jest experimentation

.eslintrc.json

@@ -2,7 +2,8 @@
 	"env": {
 		"node": true,
 		"commonjs": true,
-		"es2021": true
+		"es2021": true,
+		"jest": true
 	},
 	"extends": "eslint:recommended",
 	"parserOptions": {

.gitignore

@@ -118,3 +118,5 @@ dist
 *.torrent
 torrents/
 config.js
+output/
+input/

__mocks__/fs.js

@@ -0,0 +1,32 @@
+"use strict";
+
+const path = require("path");
+
+const fs = jest.createMockFromModule("fs");
+
+// This is a custom function that our tests can use during setup to specify
+// what the files on the "mock" filesystem should look like when any of the
+// `fs` APIs are used.
+let mockFiles = Object.create(null);
+function __setMockFiles(newMockFiles) {
+	mockFiles = Object.create(null);
+	for (const file in newMockFiles) {
+		const dir = path.dirname(file);
+
+		if (!mockFiles[dir]) {
+			mockFiles[dir] = [];
+		}
+		mockFiles[dir].push(path.basename(file));
+	}
+}
+
+// A custom version of `readdirSync` that reads from the special mocked out
+// file list set via __setMockFiles
+function readdirSync(directoryPath) {
+	return mockFiles[directoryPath] || [];
+}
+
+fs.__setMockFiles = __setMockFiles;
+fs.readdirSync = readdirSync;
+
+module.exports = fs;

__mocks__/path.js

@@ -0,0 +1,13 @@
+"use strict";
+
+const path = jest.createMockFromModule("path");
+
+// A custom version of `readdirSync` that reads from the special mocked out
+// file list set via __setMockFiles
+function join(...args) {
+	return args.join("/");
+}
+
+path.join = join;
+
+module.exports = path;