node: Use JSON for control commands

radicle-node/src/control.rs

@@ -5,15 +5,15 @@ use std::io::LineWriter;
 use std::os::unix::net::UnixListener;
 use std::os::unix::net::UnixStream;
 use std::path::PathBuf;
+use std::str::FromStr;
 use std::{io, net};
 
 use radicle::node::Handle;
 use serde_json as json;
 
 use crate::identity::Id;
-use crate::node;
-use crate::node::FetchResult;
 use crate::node::NodeId;
+use crate::node::{Command, CommandName, CommandResult, FetchResult};
 use crate::runtime;
 
 #[derive(thiserror::Error, Debug)]
@@ -44,7 +44,7 @@ pub fn listen<H: Handle<Error = runtime::HandleError, FetchResult = FetchResult>
                         handle.shutdown().ok();
                         break;
                     }
-                    writeln!(stream, "error: {e}").ok();
+                    CommandResult::error(e).to_writer(&mut stream).ok();
 
                     stream.flush().ok();
                     stream.shutdown(net::Shutdown::Both).ok();
@@ -62,6 +62,8 @@ pub fn listen<H: Handle<Error = runtime::HandleError, FetchResult = FetchResult>
 enum CommandError {
     #[error("invalid command argument `{0}`, {1}")]
     InvalidCommandArg(String, Box<dyn std::error::Error>),
+    #[error("invalid command arguments `{0:?}`")]
+    InvalidCommandArgs(Vec<String>),
     #[error("unknown command `{0}`")]
     UnknownCommand(String),
     #[error("serialization failed: {0}")]
@@ -83,151 +85,97 @@ fn command<H: Handle<Error = runtime::HandleError, FetchResult = FetchResult>>(
     let mut line = String::new();
 
     reader.read_line(&mut line)?;
+    let input = line.trim_end();
 
-    let cmd = line.trim_end();
+    log::debug!(target: "control", "Received `{input}` on control socket");
+    let cmd: Command = json::from_str(input)?;
 
-    log::debug!(target: "control", "Received `{cmd}` on control socket");
+    match cmd.name {
+        CommandName::Fetch => {
+            let (rid, nid): (Id, NodeId) = parse::args(cmd)?;
+            fetch(rid, nid, LineWriter::new(stream), handle)?;
+        }
+        CommandName::Seeds => {
+            let rid: Id = parse::arg(cmd)?;
+            let seeds = handle.seeds(rid)?;
 
-    // TODO: refactor to include helper
+            json::to_writer(writer, &seeds)?;
-    match cmd.split_once(' ') {
+        }
-        Some(("fetch", args)) => {
+        CommandName::TrackRepo => {
-            if let Some((rid, node)) = args.split_once(' ') {
+            let rid: Id = parse::arg(cmd)?;
-                let rid: Id = rid
+
-                    .parse()
+            match handle.track_repo(rid) {
-                    .map_err(|e| CommandError::InvalidCommandArg(rid.to_owned(), Box::new(e)))?;
+                Ok(updated) => {
-                let node: NodeId = node
+                    CommandResult::Okay { updated }.to_writer(writer)?;
+                }
+                Err(e) => {
+                    return Err(CommandError::Runtime(e));
+                }
+            }
+        }
+        CommandName::UntrackRepo => {
+            let rid: Id = parse::arg(cmd)?;
+
+            match handle.untrack_repo(rid) {
+                Ok(updated) => {
+                    CommandResult::Okay { updated }.to_writer(writer)?;
+                }
+                Err(e) => {
+                    return Err(CommandError::Runtime(e));
+                }
+            }
+        }
+        CommandName::TrackNode => {
+            let (node, alias) = match cmd.args.as_slice() {
+                [node] => (node.as_str(), None),
+                [node, alias] => (node.as_str(), Some(alias.to_owned())),
+                _ => return Err(CommandError::InvalidCommandArgs(cmd.args)),
+            };
+            let nid = node
                 .parse()
                 .map_err(|e| CommandError::InvalidCommandArg(node.to_owned(), Box::new(e)))?;
 
-                fetch(rid, node, LineWriter::new(stream), handle)?;
+            match handle.track_node(nid, alias) {
+                Ok(updated) => {
+                    CommandResult::Okay { updated }.to_writer(writer)?;
+                }
+                Err(e) => {
+                    return Err(CommandError::Runtime(e));
                 }
             }
-        Some(("seeds", arg)) => {
+        }
-            let rid: Id = arg
+        CommandName::UntrackNode => {
-                .parse()
+            let nid: NodeId = parse::arg(cmd)?;
-                .map_err(|e| CommandError::InvalidCommandArg(arg.to_owned(), Box::new(e)))?;
 
-            for seed in handle.seeds(rid)? {
+            match handle.untrack_node(nid) {
-                writeln!(writer, "{seed}")?;
-            }
-        }
-        Some(("track-repo", arg)) => match arg.parse() {
-            Ok(id) => match handle.track_repo(id) {
                 Ok(updated) => {
-                    if updated {
+                    CommandResult::Okay { updated }.to_writer(writer)?;
-                        writeln!(writer, "{}", node::RESPONSE_OK)?;
-                    } else {
-                        writeln!(writer, "{}", node::RESPONSE_NOOP)?;
-                    }
                 }
                 Err(e) => {
                     return Err(CommandError::Runtime(e));
                 }
-            },
-            Err(err) => {
-                return Err(CommandError::InvalidCommandArg(
-                    arg.to_owned(),
-                    Box::new(err),
-                ));
-            }
-        },
-        Some(("untrack-repo", arg)) => match arg.parse() {
-            Ok(id) => match handle.untrack_repo(id) {
-                Ok(updated) => {
-                    if updated {
-                        writeln!(writer, "{}", node::RESPONSE_OK)?;
-                    } else {
-                        writeln!(writer, "{}", node::RESPONSE_NOOP)?;
             }
         }
-                Err(e) => {
+        CommandName::AnnounceRefs => {
-                    return Err(CommandError::Runtime(e));
+            let rid: Id = parse::arg(cmd)?;
-                }
-            },
-            Err(err) => {
-                return Err(CommandError::InvalidCommandArg(
-                    arg.to_owned(),
-                    Box::new(err),
-                ));
-            }
-        },
-        Some(("track-node", args)) => {
-            let (peer, alias) = if let Some((peer, alias)) = args.split_once(' ') {
-                (peer, Some(alias.to_owned()))
-            } else {
-                (args, None)
-            };
-            match peer.parse() {
-                Ok(id) => match handle.track_node(id, alias) {
-                    Ok(updated) => {
-                        if updated {
-                            writeln!(writer, "{}", node::RESPONSE_OK)?;
-                        } else {
-                            writeln!(writer, "{}", node::RESPONSE_NOOP)?;
-                        }
-                    }
-                    Err(e) => {
-                        return Err(CommandError::Runtime(e));
-                    }
-                },
-                Err(err) => {
-                    return Err(CommandError::InvalidCommandArg(
-                        args.to_owned(),
-                        Box::new(err),
-                    ));
-                }
-            }
-        }
-        Some(("untrack-node", arg)) => match arg.parse() {
-            Ok(id) => match handle.untrack_node(id) {
-                Ok(updated) => {
-                    if updated {
-                        writeln!(writer, "{}", node::RESPONSE_OK)?;
-                    } else {
-                        writeln!(writer, "{}", node::RESPONSE_NOOP)?;
-                    }
-                }
-                Err(e) => {
-                    return Err(CommandError::Runtime(e));
-                }
-            },
-            Err(err) => {
-                return Err(CommandError::InvalidCommandArg(
-                    arg.to_owned(),
-                    Box::new(err),
-                ));
-            }
-        },
-        Some(("announce-refs", arg)) => match arg.parse() {
-            Ok(id) => {
-                if let Err(e) = handle.announce_refs(id) {
-                    return Err(CommandError::Runtime(e));
-                }
-                writeln!(writer, "{}", node::RESPONSE_OK)?;
-            }
-            Err(err) => {
-                return Err(CommandError::InvalidCommandArg(
-                    arg.to_owned(),
-                    Box::new(err),
-                ));
-            }
-        },
-        Some((cmd, _)) => return Err(CommandError::UnknownCommand(cmd.to_owned())),
 
-        // Commands with no arguments.
+            if let Err(e) = handle.announce_refs(rid) {
-        None => match cmd {
+                return Err(CommandError::Runtime(e));
-            "status" => {
-                writeln!(writer, "{}", node::RESPONSE_OK).ok();
             }
-            "routing" => match handle.routing() {
+            CommandResult::ok().to_writer(writer).ok();
+        }
+        CommandName::Status => {
+            CommandResult::ok().to_writer(writer).ok();
+        }
+        CommandName::Routing => match handle.routing() {
             Ok(c) => {
                 for (id, seed) in c.iter() {
-                        writeln!(writer, "{id} {seed}",)?;
+                    writeln!(writer, "{id} {seed}")?;
                 }
             }
             Err(e) => return Err(CommandError::Runtime(e)),
         },
-            "inventory" => match handle.inventory() {
+        CommandName::Inventory => match handle.inventory() {
             Ok(c) => {
                 for id in c.iter() {
                     writeln!(writer, "{id}")?;
@@ -235,13 +183,12 @@ fn command<H: Handle<Error = runtime::HandleError, FetchResult = FetchResult>>(
             }
             Err(e) => return Err(CommandError::Runtime(e)),
         },
-            "shutdown" => {
+        CommandName::Shutdown => {
             return Err(CommandError::Shutdown);
         }
         _ => {
             return Err(CommandError::UnknownCommand(line));
         }
-        },
     }
     Ok(())
 }
@@ -263,6 +210,45 @@ fn fetch<W: Write, H: Handle<Error = runtime::HandleError, FetchResult = FetchRe
     Ok(())
 }
 
+mod parse {
+    use super::*;
+
+    pub(super) fn arg<T: FromStr>(cmd: Command) -> Result<T, CommandError>
+    where
+        <T as FromStr>::Err: std::error::Error + 'static,
+    {
+        let [arg]: [String; 1] = cmd
+            .args
+            .clone()
+            .try_into()
+            .map_err(|_| CommandError::InvalidCommandArgs(cmd.args))?;
+
+        arg.parse()
+            .map_err(|e| CommandError::InvalidCommandArg(arg, Box::new(e)))
+    }
+
+    pub(super) fn args<S: FromStr, T: FromStr>(cmd: Command) -> Result<(S, T), CommandError>
+    where
+        <S as FromStr>::Err: std::error::Error + 'static,
+        <T as FromStr>::Err: std::error::Error + 'static,
+    {
+        let [arg1, arg2]: [String; 2] = cmd
+            .args
+            .clone()
+            .try_into()
+            .map_err(|_| CommandError::InvalidCommandArgs(cmd.args))?;
+
+        let arg1 = arg1
+            .parse()
+            .map_err(|e| CommandError::InvalidCommandArg(arg1, Box::new(e)))?;
+        let arg2 = arg2
+            .parse()
+            .map_err(|e| CommandError::InvalidCommandArg(arg2, Box::new(e)))?;
+
+        Ok((arg1, arg2))
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::io::prelude::*;
@@ -290,15 +276,22 @@ mod tests {
         });
 
         for proj in &projs {
-            let mut buf = [0; 2];
+            let stream = loop {
-            let mut stream = loop {
                 if let Ok(stream) = UnixStream::connect(&socket) {
                     break stream;
                 }
             };
-            writeln!(&stream, "announce-refs {proj}").unwrap();
+            writeln!(
-            stream.read_exact(&mut buf).unwrap();
+                &stream,
-            assert_eq!(&buf, &[b'o', b'k']);
+                "{}",
+                json::to_string(&Command::new(CommandName::AnnounceRefs, [proj])).unwrap()
+            )
+            .unwrap();
+
+            let stream = BufReader::new(stream);
+            let line = stream.lines().next().unwrap().unwrap();
+
+            assert_eq!(line, json::json!({ "status": "ok" }).to_string());
         }
 
         for proj in &projs {

radicle-node/src/runtime/handle.rs

@@ -1,5 +1,5 @@
 use std::fmt;
-use std::io::{self, Write};
+use std::io;
 use std::os::unix::net::UnixStream;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
@@ -10,7 +10,7 @@ use thiserror::Error;
 
 use crate::crypto::Signer;
 use crate::identity::Id;
-use crate::node::FetchResult;
+use crate::node::{Command, FetchResult};
 use crate::profile::Home;
 use crate::service;
 use crate::service::{CommandError, QueryState};
@@ -221,7 +221,7 @@ impl<G: Signer + EcSign + 'static> radicle::node::Handle for Handle<G> {
         // control thread gracefully. Since the control thread may have called this function,
         // the control socket may already be disconnected. Ignore errors.
         UnixStream::connect(self.home.socket())
-            .and_then(|mut sock| sock.write_all(b"shutdown"))
+            .and_then(|sock| Command::SHUTDOWN.to_writer(sock))
             .ok();
 
         self.controller.shutdown().map_err(|_| Error::NotConnected)

radicle/src/node.rs

@@ -1,14 +1,14 @@
 mod features;
 
-use std::io::{BufRead, BufReader, Write};
+use std::io::{BufRead, BufReader};
 use std::os::unix::net::UnixStream;
 use std::path::{Path, PathBuf};
-use std::str::FromStr;
+use std::{fmt, io, net};
-use std::{io, net};
 
 use amplify::WrapperMut;
 use crossbeam_channel as chan;
 use cyphernet::addr::{HostName, NetAddr};
+use serde::de::DeserializeOwned;
 use serde::{Deserialize, Serialize};
 use serde_json as json;
 
@@ -22,10 +22,58 @@ pub use features::Features;
 pub const DEFAULT_SOCKET_NAME: &str = "radicle.sock";
 /// Default radicle protocol port.
 pub const DEFAULT_PORT: u16 = 8776;
-/// Response on node socket indicating that a command was carried out successfully.
+
-pub const RESPONSE_OK: &str = "ok";
+/// Result of a command, on the node control socket.
-/// Response on node socket indicating that a command had no effect.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub const RESPONSE_NOOP: &str = "noop";
+#[serde(tag = "status")]
+pub enum CommandResult {
+    /// Response on node socket indicating that a command was carried out successfully.
+    #[serde(rename = "ok")]
+    Okay {
+        /// Whether the command had any effect.
+        #[serde(default, skip_serializing_if = "crate::serde_ext::is_default")]
+        updated: bool,
+    },
+    /// Response on node socket indicating that an error occured.
+    Error {
+        /// The reason for the error.
+        reason: String,
+    },
+}
+
+impl CommandResult {
+    /// Create an "updated" response.
+    pub fn updated() -> Self {
+        Self::Okay { updated: true }
+    }
+
+    /// Create an "ok" response.
+    pub fn ok() -> Self {
+        Self::Okay { updated: false }
+    }
+
+    /// Create an error result.
+    pub fn error(err: impl std::error::Error) -> Self {
+        Self::Error {
+            reason: err.to_string(),
+        }
+    }
+
+    /// Write this command result to a stream, including a terminating LF character.
+    pub fn to_writer(&self, mut w: impl io::Write) -> io::Result<()> {
+        json::to_writer(&mut w, self).map_err(|_| io::ErrorKind::InvalidInput)?;
+        w.write_all(b"\n")
+    }
+}
+
+impl From<CommandResult> for Result<bool, Error> {
+    fn from(value: CommandResult) -> Self {
+        match value {
+            CommandResult::Okay { updated } => Ok(updated),
+            CommandResult::Error { reason } => Err(Error::Node(reason)),
+        }
+    }
+}
 
 /// Peer public protocol address.
 #[derive(Wrapper, WrapperMut, Clone, Eq, PartialEq, Debug, From)]
@@ -54,6 +102,82 @@ impl From<net::SocketAddr> for Address {
     }
 }
 
+/// Command name.
+#[derive(Debug, Copy, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum CommandName {
+    /// Announce repository references for given repository to peers.
+    AnnounceRefs,
+    /// Connect to node with the given address.
+    Connect,
+    /// Lookup seeds for the given repository in the routing table.
+    Seeds,
+    /// Fetch the given repository from the network.
+    Fetch,
+    /// Track the given repository.
+    TrackRepo,
+    /// Untrack the given repository.
+    UntrackRepo,
+    /// Track the given node.
+    TrackNode,
+    /// Untrack the given node.
+    UntrackNode,
+    /// Get the node's inventory.
+    Inventory,
+    /// Get the node's routing table.
+    Routing,
+    /// Get the node's status.
+    Status,
+    /// Shutdown the node.
+    Shutdown,
+}
+
+impl fmt::Display for CommandName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // SAFETY: The enum can always be converted to a value.
+        #[allow(clippy::unwrap_used)]
+        let val = json::to_value(self).unwrap();
+        // SAFETY: The value is always a string.
+        #[allow(clippy::unwrap_used)]
+        let s = val.as_str().unwrap();
+
+        write!(f, "{s}")
+    }
+}
+
+/// Commands sent to the node via the control socket.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Command {
+    /// Command name.
+    #[serde(rename = "cmd")]
+    pub name: CommandName,
+    /// Command arguments.
+    #[serde(rename = "args")]
+    pub args: Vec<String>,
+}
+
+impl Command {
+    /// Shutdown command.
+    pub const SHUTDOWN: Self = Self {
+        name: CommandName::Shutdown,
+        args: vec![],
+    };
+
+    /// Create a new command.
+    pub fn new<T: ToString>(name: CommandName, args: impl IntoIterator<Item = T>) -> Self {
+        Self {
+            name,
+            args: args.into_iter().map(|a| a.to_string()).collect(),
+        }
+    }
+
+    /// Write this command to a stream, including a terminating LF character.
+    pub fn to_writer(&self, mut w: impl io::Write) -> io::Result<()> {
+        json::to_writer(&mut w, self).map_err(|_| io::ErrorKind::InvalidInput)?;
+        w.write_all(b"\n")
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(tag = "status", rename_all = "kebab-case")]
 pub enum FetchResult {
@@ -85,20 +209,30 @@ impl<S: ToString> From<Result<Vec<RefUpdate>, S>> for FetchResult {
     }
 }
 
+/// Error returned by [`Handle`] functions.
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
     #[error("failed to connect to node: {0}")]
     Connect(#[from] io::Error),
-    #[error("received invalid response for `{cmd}` command: '{response}'")]
+    #[error("failed to call node: {0}")]
-    InvalidResponse { cmd: &'static str, response: String },
+    Call(#[from] CallError),
+    #[error("node: {0}")]
+    Node(String),
+    #[error("received empty response for `{cmd}` command")]
+    EmptyResponse { cmd: CommandName },
+}
+
+/// Error returned by [`Node::call`] iterator.
+#[derive(thiserror::Error, Debug)]
+pub enum CallError {
+    #[error("i/o: {0}")]
+    Io(#[from] io::Error),
     #[error("received invalid json in response for `{cmd}` command: '{response}': {error}")]
     InvalidJson {
-        cmd: &'static str,
+        cmd: CommandName,
         response: String,
         error: json::Error,
     },
-    #[error("received empty response for `{cmd}` command")]
-    EmptyResponse { cmd: &'static str },
 }
 
 /// A handle to send commands to the node or request information.
@@ -157,24 +291,24 @@ impl Node {
     }
 
     /// Call a command on the node.
-    pub fn call<A: ToString>(
+    pub fn call<A: ToString, T: DeserializeOwned>(
         &self,
-        cmd: &str,
+        name: CommandName,
-        args: &[A],
+        args: impl IntoIterator<Item = A>,
-    ) -> Result<impl Iterator<Item = Result<String, io::Error>>, io::Error> {
+    ) -> Result<impl Iterator<Item = Result<T, CallError>>, io::Error> {
         let stream = UnixStream::connect(&self.socket)?;
-        let args = args
+        Command::new(name, args).to_writer(&stream)?;
-            .iter()
-            .map(ToString::to_string)
-            .collect::<Vec<_>>()
-            .join(" ");
 
-        if args.is_empty() {
+        Ok(BufReader::new(stream).lines().map(move |l| {
-            writeln!(&stream, "{cmd}")?;
+            let l = l?;
-        } else {
+            let v = json::from_str(&l).map_err(|e| CallError::InvalidJson {
-            writeln!(&stream, "{cmd} {args}")?;
+                cmd: name,
-        }
+                response: l,
-        Ok(BufReader::new(stream).lines())
+                error: e,
+            })?;
+
+            Ok(v)
+        }))
     }
 }
 
@@ -184,13 +318,13 @@ impl Handle for Node {
     type FetchResult = FetchResult;
 
     fn is_running(&self) -> bool {
-        let Ok(mut lines) = self.call::<&str>("status", &[]) else {
+        let Ok(mut lines) = self.call::<&str, CommandResult>(CommandName::Status, []) else {
             return false;
         };
-        let Some(Ok(line)) = lines.next() else {
+        let Some(Ok(result)) = lines.next() else {
             return false;
         };
-        line == RESPONSE_OK
+        matches!(result, CommandResult::Okay { .. })
     }
 
     fn connect(&mut self, _node: NodeId, _addr: Address) -> Result<(), Error> {
@@ -198,113 +332,73 @@ impl Handle for Node {
     }
 
     fn seeds(&mut self, id: Id) -> Result<Vec<NodeId>, Error> {
-        self.call("seeds", &[id.urn()])?
+        let seeds: Vec<NodeId> =
-            .map(|line| {
+            self.call(CommandName::Seeds, [id.urn()])?
-                let line = line?;
+                .next()
-                let node = NodeId::from_str(&line).map_err(|_| Error::InvalidResponse {
+                .ok_or(Error::EmptyResponse {
-                    cmd: "seeds",
+                    cmd: CommandName::Seeds,
-                    response: line,
+                })??;
-                })?;
+
-                Ok(node)
+        Ok(seeds)
-            })
-            .collect()
     }
 
     fn fetch(&mut self, id: Id, from: NodeId) -> Result<Self::FetchResult, Error> {
         let result = self
-            .call("fetch", &[id.urn(), from.to_human()])?
+            .call(CommandName::Fetch, [id.urn(), from.to_human()])?
             .next()
-            .ok_or(Error::EmptyResponse { cmd: "fetch" })??;
+            .ok_or(Error::EmptyResponse {
-        let lookup = json::from_str(&result).map_err(|e| Error::InvalidJson {
+                cmd: CommandName::Fetch,
-            cmd: "fetch",
+            })??;
-            response: result,
-            error: e,
-        })?;
 
-        Ok(lookup)
+        Ok(result)
     }
 
     fn track_node(&mut self, id: NodeId, alias: Option<String>) -> Result<bool, Error> {
         let id = id.to_human();
-        let mut line = if let Some(alias) = alias.as_deref() {
+        let args = if let Some(alias) = alias.as_deref() {
-            self.call("track-node", &[id.as_str(), alias])
+            vec![id.as_str(), alias]
         } else {
-            self.call("track-node", &[id.as_str()])
+            vec![id.as_str()]
-        }?;
+        };
-        let line = line
-            .next()
-            .ok_or(Error::EmptyResponse { cmd: "track-node" })??;
 
-        log::debug!("node: {}", line);
+        let mut line = self.call(CommandName::TrackNode, args)?;
+        let response: CommandResult = line.next().ok_or(Error::EmptyResponse {
+            cmd: CommandName::TrackNode,
+        })??;
 
-        match line.as_str() {
+        response.into()
-            RESPONSE_OK => Ok(true),
-            RESPONSE_NOOP => Ok(false),
-            _ => Err(Error::InvalidResponse {
-                cmd: "track-node",
-                response: line,
-            }),
-        }
     }
 
     fn track_repo(&mut self, id: Id) -> Result<bool, Error> {
-        let mut line = self.call("track-repo", &[id.urn()])?;
+        let mut line = self.call(CommandName::TrackRepo, [id.urn()])?;
-        let line = line
+        let response: CommandResult = line.next().ok_or(Error::EmptyResponse {
-            .next()
+            cmd: CommandName::TrackRepo,
-            .ok_or(Error::EmptyResponse { cmd: "track-repo" })??;
+        })??;
 
-        log::debug!("node: {}", line);
+        response.into()
-
-        match line.as_str() {
-            RESPONSE_OK => Ok(true),
-            RESPONSE_NOOP => Ok(false),
-            _ => Err(Error::InvalidResponse {
-                cmd: "track-repo",
-                response: line,
-            }),
-        }
     }
 
     fn untrack_node(&mut self, id: NodeId) -> Result<bool, Error> {
-        let mut line = self.call("untrack-node", &[id])?;
+        let mut line = self.call(CommandName::UntrackNode, [id])?;
-        let line = line.next().ok_or(Error::EmptyResponse {
+        let response: CommandResult = line.next().ok_or(Error::EmptyResponse {
-            cmd: "untrack-node",
+            cmd: CommandName::UntrackNode,
         })??;
 
-        log::debug!("node: {}", line);
+        response.into()
-
-        match line.as_str() {
-            RESPONSE_OK => Ok(true),
-            RESPONSE_NOOP => Ok(false),
-            _ => Err(Error::InvalidResponse {
-                cmd: "untrack-node",
-                response: line,
-            }),
-        }
     }
 
     fn untrack_repo(&mut self, id: Id) -> Result<bool, Error> {
-        let mut line = self.call("untrack-repo", &[id.urn()])?;
+        let mut line = self.call(CommandName::UntrackRepo, [id.urn()])?;
-        let line = line.next().ok_or(Error::EmptyResponse {
+        let response: CommandResult = line.next().ok_or(Error::EmptyResponse {
-            cmd: "untrack-repo",
+            cmd: CommandName::UntrackRepo,
         })??;
 
-        log::debug!("node: {}", line);
+        response.into()
-
-        match line.as_str() {
-            RESPONSE_OK => Ok(true),
-            RESPONSE_NOOP => Ok(false),
-            _ => Err(Error::InvalidResponse {
-                cmd: "untrack-repo",
-                response: line,
-            }),
-        }
     }
 
     fn announce_refs(&mut self, id: Id) -> Result<(), Error> {
-        for line in self.call("announce-refs", &[id.urn()])? {
+        for line in self.call(CommandName::AnnounceRefs, [id.urn()])? {
-            let line = line?;
+            line?;
-            log::debug!("node: {}", line);
         }
         Ok(())
     }
@@ -325,3 +419,13 @@ impl Handle for Node {
         todo!();
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_command_name_display() {
+        assert_eq!(CommandName::TrackNode.to_string(), "track-node");
+    }
+}

radicle/src/serde_ext.rs

@@ -23,3 +23,8 @@ pub mod string {
             .map_err(de::Error::custom)
     }
 }
+
+/// Return true if the given value is the default for that type.
+pub fn is_default<T: Default + PartialEq>(t: &T) -> bool {
+    t == &T::default()
+}