panic on unknown CLI arguments

Currently silently ignores which is not helpful ...

crates/notedeck/src/app.rs

@@ -7,6 +7,7 @@ use egui::ThemePreference;
 use enostr::RelayPool;
 use nostrdb::{Config, Ndb, Transaction};
 use std::cell::RefCell;
+use std::collections::BTreeSet;
 use std::path::Path;
 use std::rc::Rc;
 use tracing::{error, info};
@@ -29,6 +30,7 @@ pub struct Notedeck {
     app: Option<Rc<RefCell<dyn App>>>,
     zoom: ZoomHandler,
     app_size: AppSizeHandler,
+    unrecognized_args: BTreeSet<String>,
 }
 
 fn margin_top(narrow: bool) -> f32 {
@@ -106,7 +108,9 @@ impl Notedeck {
         #[cfg(feature = "profiling")]
         setup_profiling();
 
-        let parsed_args = Args::parse(args);
+        // Skip the first argument, which is the program name.
+        let args_to_parse: Vec<String> = args[1..].to_vec();
+        let (parsed_args, unrecognized_args) = Args::parse(&args_to_parse);
 
         let data_path = parsed_args
             .datapath
@@ -203,6 +207,7 @@ impl Notedeck {
             app: None,
             zoom,
             app_size,
+            unrecognized_args,
         }
     }
 
@@ -236,4 +241,8 @@ impl Notedeck {
     pub fn theme(&self) -> ThemePreference {
         self.theme.load()
     }
+
+    pub fn unrecognized_args(&self) -> &BTreeSet<String> {
+        &self.unrecognized_args
+    }
 }

crates/notedeck/src/args.rs

@@ -1,3 +1,5 @@
+use std::collections::BTreeSet;
+
 use enostr::{Keypair, Pubkey, SecretKey};
 use tracing::error;
 
@@ -18,7 +20,9 @@ pub struct Args {
 }
 
 impl Args {
-    pub fn parse(args: &[String]) -> Self {
+    // parse arguments, return set of unrecognized args
+    pub fn parse(args: &[String]) -> (Self, BTreeSet<String>) {
+        let mut unrecognized_args = BTreeSet::new();
         let mut res = Args {
             relays: vec![],
             is_mobile: None,
@@ -112,11 +116,13 @@ impl Args {
                 res.use_keystore = false;
             } else if arg == "--relay-debug" {
                 res.relay_debug = true;
+            } else {
+                unrecognized_args.insert(arg.clone());
             }
 
             i += 1;
         }
 
-        res
+        (res, unrecognized_args)
     }
 }