TypeScript Conversion (#425)

Follows #424. Converts the upcoming 1.0.0 branch based on native browser-based traffic capture and recording to TypeScript. Fixes #426

---------
Co-authored-by: Tessa Walsh <tessa@bitarchivist.net>
Co-authored-by: emma <hi@emma.cafe>

src/util/file_reader.ts

@@ -0,0 +1,34 @@
+import fs from "fs";
+import path from "path";
+
+const MAX_DEPTH = 2;
+
+export function collectAllFileSources(fileOrDir: string, ext?: string, depth = 0) : string[] {
+  const resolvedPath = path.resolve(fileOrDir);
+
+  if (depth >= MAX_DEPTH) {
+    console.warn(`WARN: MAX_DEPTH of ${MAX_DEPTH} reached traversing "${resolvedPath}"`);
+    return [];
+  }
+
+  const stat = fs.statSync(resolvedPath);
+
+  if (stat.isFile() && (ext === null || path.extname(resolvedPath) === ext)) {
+    const contents = fs.readFileSync(resolvedPath);
+    return [`/* src: ${resolvedPath} */\n\n${contents}`];
+  }
+
+  if (stat.isDirectory()) {
+    const files = fs.readdirSync(resolvedPath);
+    return files.reduce((acc: string[], next: string) => {
+      const nextPath = path.join(fileOrDir, next);
+      return [...acc, ...collectAllFileSources(nextPath, ext, depth + 1)];
+    }, []);
+  }
+
+  if (depth === 0) {
+    console.warn(`WARN: The provided path "${resolvedPath}" is not a .js file or directory.`);
+  }
+
+  return [];
+}