Use json_comments crate to skip config file comments

Cargo.toml

@@ -124,6 +124,7 @@ indicatif = { version = "0.15.0", features = ["with_rayon"] }
 insta = { version = "1.26.0", features = ["json", "yaml"] }
 itertools = "0.10.0"
 itoa = "1.0"
+json_comments = "0.2.1"
 libc = "0.2.81"
 libfuzzer-sys = { version = "0.4", features = ["arbitrary-derive"] }
 log = "0.4"

core/chain-configs/Cargo.toml

@@ -14,6 +14,7 @@ description = "This crate provides typed interfaces to the NEAR Genesis and Chai
 anyhow.workspace = true
 chrono.workspace = true
 derive_more.workspace = true
+json_comments.workspace = true
 num-rational.workspace = true
 once_cell.workspace = true
 serde.workspace = true

core/chain-configs/src/genesis_config.rs

@@ -35,6 +35,7 @@ use near_primitives::{
     },
     version::ProtocolVersion,
 };
+use json_comments::StripComments;
 
 const MAX_GAS_PRICE: Balance = 10_000_000_000_000_000_000_000;
 
@@ -271,7 +272,9 @@ impl GenesisConfig {
     pub fn from_file<P: AsRef<Path>>(path: P) -> anyhow::Result<Self> {
         let file = File::open(path).with_context(|| "Could not open genesis config file.")?;
         let reader = BufReader::new(file);
-        let genesis_config: GenesisConfig = serde_json::from_reader(reader)
+        // Strip the comments from the input (use `as_bytes()` to get a `Read`).
+        let stripped = StripComments::new(reader);
+        let genesis_config: GenesisConfig = serde_json::from_reader(stripped)
             .with_context(|| "Failed to deserialize the genesis records.")?;
         Ok(genesis_config)
     }

nearcore/Cargo.toml

@@ -20,6 +20,7 @@ futures.workspace = true
 hyper-tls.workspace = true
 hyper.workspace = true
 indicatif.workspace = true
+json_comments.workspace = true
 num-rational.workspace = true
 once_cell.workspace = true
 rand.workspace = true

nearcore/src/config.rs

@@ -11,6 +11,7 @@ use near_primitives::test_utils::create_test_signer;
 use near_primitives::time::Clock;
 use num_rational::Rational32;
 use serde::{Deserialize, Serialize};
+use json_comments::StripComments;
 #[cfg(test)]
 use tempfile::tempdir;
 use tracing::{info, warn};
@@ -391,8 +392,10 @@ impl Config {
         let contents = std::fs::read_to_string(path)
             .with_context(|| format!("Failed to read config from {}", path.display()))?;
         let mut unrecognised_fields = Vec::new();
+        let mut contents_without_comments = String::new();
+        StripComments::new(contents.as_bytes()).read_to_string(&mut contents_without_comments).unwrap();
         let config: Config = serde_ignored::deserialize(
-            &mut serde_json::Deserializer::from_str(&contents),
+            &mut serde_json::Deserializer::from_str(&contents_without_comments),
             |field| {
                 let field = field.to_string();
                 // TODO(mina86): Remove this deprecation notice some time by the

nearcore/src/dyn_config.rs

@@ -4,6 +4,7 @@ use near_dyn_configs::{UpdateableConfigLoaderError, UpdateableConfigs};
 use near_o11y::log_config::LogConfig;
 use serde::Deserialize;
 use std::path::{Path, PathBuf};
+use json_comments::StripComments;
 
 const LOG_CONFIG_FILENAME: &str = "log_config.json";
 
@@ -59,13 +60,18 @@ where
     for<'a> T: Deserialize<'a>,
 {
     match std::fs::read_to_string(path) {
-        Ok(config_str) => match serde_json::from_str::<T>(&config_str) {
-            Ok(config) => {
-                tracing::info!(target: "neard", config=?config, "Changing the config {path:?}.");
-                return Ok(Some(config));
+        Ok(config_str) => {
+            // Strip the comments from the input (use `as_bytes()` to get a `Read`).
+            let stripped = StripComments::new(config_str.as_bytes());
+
+            match serde_json::from_reader(stripped) {
+                Ok(config) => {
+                    tracing::info!(target: "neard", config=?config, "Changing the config {path:?}.");
+                    return Ok(Some(config));
+                }
+                Err(err) => Err(UpdateableConfigLoaderError::Parse { file: path.to_path_buf(), err }),
             }
-            Err(err) => Err(UpdateableConfigLoaderError::Parse { file: path.to_path_buf(), err }),
-        },
+       },
         Err(err) => match err.kind() {
             std::io::ErrorKind::NotFound => {
                 tracing::info!(target: "neard", ?err, "Reset the config {path:?} because the config file doesn't exist.");