add an error if you try to add a url that exists.

cli/src/commands.rs

@@ -42,7 +42,12 @@ fn json_printing(site: &Site) -> Result<(), Error> {
 	}
 }
 
-fn filter_site(site: &Site, json: bool, seperator: &Option<char>, group: &PrintGroup) -> Result<(), Error> {
+fn filter_site(
+	site: &Site,
+	json: bool,
+	seperator: &Option<char>,
+	group: &PrintGroup,
+) -> Result<(), Error> {
 	if json {
 		json_printing(site)?;
 		return Ok(());
@@ -69,7 +74,10 @@ pub(crate) fn print(
 	if let Some(filter) = filter {
 		names.retain(|f| &f.url == filter);
 		if names.len() == 0 {
-			return Err(Error { status: ErrorStatus::NotFoundError, data: "this url was not found in names.json".into() }) 
+			return Err(Error {
+				status: ErrorStatus::NotFoundError,
+				data: "this url was not found in names.json".into(),
+			});
 		}
 		return filter_site(&names[0], json, seperator, group);
 	}
@@ -95,6 +103,15 @@ pub(crate) fn add(path: &Path, url: &String, name: &Option<String>) -> Result<()
 	let names_file = names::read_names_file(path)?;
 	let mut names = names::load_names(names_file)?;
 
+	if names.iter().any(|site| site.url.contains(url)) {
+		return Err(Error {
+			status: ErrorStatus::AlreadyExistsError,
+			data:
+				"this url already exists in names.json. you can't have more then 1 of the same url."
+					.into(),
+		});
+	}
+
 	let site = Site {
 		url: url.to_string(),
 		name: name.to_owned(),

shared/src/errors.rs

@@ -4,7 +4,8 @@ pub enum ErrorStatus {
 	ParsingError,
 	DirectoriesError,
 	LoggerInitializationError,
-	NotFoundError
+	NotFoundError,
+	AlreadyExistsError
 }
 
 pub struct Error {