Enforce Optimistic Sync Conditions & CLI Tests (v2) (#3050)

## Description

This PR adds a single, trivial commit (f5d2b27d78) atop #2986 to resolve a tests compile error. The original author (@ethDreamer) is AFK so I'm getting this one merged ☺️ 

Please see #2986 for more information about the other, significant changes in this PR.


Co-authored-by: Mark Mackey <mark@sigmaprime.io>
Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>

common/clap_utils/src/lib.rs

@@ -6,6 +6,7 @@ use ethereum_types::U256 as Uint256;
 use ssz::Decode;
 use std::path::PathBuf;
 use std::str::FromStr;
+use types::{ChainSpec, Config, EthSpec};
 
 pub mod flags;
 
@@ -52,6 +53,12 @@ pub fn get_eth2_network_config(cli_args: &ArgMatches) -> Result<Eth2NetworkConfi
             .terminal_block_hash_activation_epoch = epoch;
     }
 
+    if let Some(slots) = parse_optional(cli_args, "safe-slots-to-import-optimistically")? {
+        eth2_network_config
+            .config
+            .safe_slots_to_import_optimistically = slots;
+    }
+
     Ok(eth2_network_config)
 }
 
@@ -157,3 +164,29 @@ pub fn parse_ssz_optional<T: Decode>(
         })
         .transpose()
 }
+
+/// Writes configs to file if `dump-config` or `dump-chain-config` flags are set
+pub fn check_dump_configs<S, E>(
+    matches: &ArgMatches,
+    config: S,
+    spec: &ChainSpec,
+) -> Result<(), String>
+where
+    S: serde::Serialize,
+    E: EthSpec,
+{
+    if let Some(dump_path) = parse_optional::<PathBuf>(matches, "dump-config")? {
+        let mut file = std::fs::File::create(dump_path)
+            .map_err(|e| format!("Failed to open file for writing config: {:?}", e))?;
+        serde_json::to_writer(&mut file, &config)
+            .map_err(|e| format!("Error serializing config: {:?}", e))?;
+    }
+    if let Some(dump_path) = parse_optional::<PathBuf>(matches, "dump-chain-config")? {
+        let chain_config = Config::from_chain_spec::<E>(spec);
+        let mut file = std::fs::File::create(dump_path)
+            .map_err(|e| format!("Failed to open file for writing chain config: {:?}", e))?;
+        serde_yaml::to_writer(&mut file, &chain_config)
+            .map_err(|e| format!("Error serializing config: {:?}", e))?;
+    }
+    Ok(())
+}