adding file name validation

src/services/fileNameValidation.ts

@@ -0,0 +1,28 @@
+export function validateFileName(fileName: string): string {
+  if (!fileName || fileName.trim() === "") {
+    return "Name cannot be empty";
+  }
+
+  const invalidChars = [":", "/", "\\", "*", "?", '"', "<", ">", "|"];
+
+  for (const char of fileName) {
+    if (invalidChars.includes(char)) {
+      return `Name contains invalid character: "${char}". Please avoid: ${invalidChars.join(
+        " "
+      )}`;
+    }
+  }
+
+  if (fileName !== fileName.trimEnd()) {
+    return "Name cannot end with whitespace";
+  }
+
+  return "";
+}
+
+export function assertValidFileName(fileName: string): void {
+  const error = validateFileName(fileName);
+  if (error) {
+    throw new Error(error);
+  }
+}