Undo some CLI flag breakages (#5902)

* Undo some CLI breakages

* Update CLI book docs

beacon_node/src/cli.rs

@@ -1101,6 +1101,8 @@ pub fn cli_app() -> Command {
                        [Enabled by default].")
                 .action(ArgAction::Set)
                 .default_value("true")
+                .num_args(0..=1)
+                .default_missing_value("true")
                 .display_order(0)
         )
         .arg(

book/src/help_bn.md

@@ -356,7 +356,7 @@ Options:
       --slasher-backend <DATABASE>
           Set the database backend to be used by the slasher. [possible values:
           lmdb, disabled]
-      --slasher-broadcast <slasher-broadcast>
+      --slasher-broadcast [<slasher-broadcast>]
           Broadcast slashings found by the slasher to the rest of the network
           [Enabled by default]. [default: true]
       --slasher-chunk-size <EPOCHS>

lighthouse/tests/beacon_node.rs

@@ -2178,6 +2178,21 @@ fn slasher_broadcast_flag_no_default() {
         });
 }
 #[test]
+fn slasher_broadcast_flag_no_argument() {
+    CommandLineTest::new()
+        .flag("slasher", None)
+        .flag("slasher-max-db-size", Some("1"))
+        .flag("slasher-broadcast", None)
+        .run_with_zero_port()
+        .with_config(|config| {
+            let slasher_config = config
+                .slasher
+                .as_ref()
+                .expect("Unable to parse Slasher config");
+            assert!(slasher_config.broadcast);
+        });
+}
+#[test]
 fn slasher_broadcast_flag_true() {
     CommandLineTest::new()
         .flag("slasher", None)

lighthouse/tests/validator_client.rs

@@ -593,14 +593,24 @@ fn wrong_broadcast_flag() {
 }
 
 #[test]
-fn latency_measurement_service() {
+fn disable_latency_measurement_service() {
     CommandLineTest::new()
         .flag("disable-latency-measurement-service", None)
         .run()
         .with_config(|config| {
             assert!(!config.enable_latency_measurement_service);
         });
 }
+#[test]
+fn latency_measurement_service() {
+    // This flag is DEPRECATED so has no effect, but should still be accepted.
+    CommandLineTest::new()
+        .flag("latency-measurement-service", Some("false"))
+        .run()
+        .with_config(|config| {
+            assert!(config.enable_latency_measurement_service);
+        });
+}
 
 #[test]
 fn validator_registration_batch_size() {

validator_client/src/cli.rs

@@ -406,6 +406,15 @@ pub fn cli_app() -> Command {
                 .help_heading(FLAG_HEADER)
                 .display_order(0)
         )
+        .arg(
+            Arg::new("latency-measurement-service")
+                .long("latency-measurement-service")
+                .help("DEPRECATED")
+                .action(ArgAction::Set)
+                .help_heading(FLAG_HEADER)
+                .display_order(0)
+                .hide(true)
+        )
         .arg(
             Arg::new("validator-registration-batch-size")
                 .long("validator-registration-batch-size")

validator_client/src/config.rs

@@ -412,6 +412,17 @@ impl Config {
         config.enable_latency_measurement_service =
             !cli_args.get_flag("disable-latency-measurement-service");
 
+        if cli_args
+            .get_one::<String>("latency-measurement-service")
+            .is_some()
+        {
+            warn!(
+                log,
+                "latency-measurement-service flag";
+                "note" => "deprecated flag has no effect and should be removed"
+            );
+        }
+
         config.validator_registration_batch_size =
             parse_required(cli_args, "validator-registration-batch-size")?;
         if config.validator_registration_batch_size == 0 {