remote-helper: Add `no-sync` push option

This is mainly useful for scripting, when for eg. you want to push
multiple things and sync only once, at the end.

radicle-cli/examples/git/git-push.md

@@ -28,12 +28,14 @@ hint: See the 'Note about fast-forwards' in 'git push --help' for details.
 
 And that we can with `+`:
 
-``` (stderr) RAD_SOCKET=/dev/null
-$ git push rad +HEAD:alice/1
+``` (stderr)
+$ git push -o no-sync rad +HEAD:alice/1
 To rad://z42hL2jL4XNk6K8oHQaSWfMgCL7ji/z6MknSLrJoTcukLrE435hVNQT4JUhbvWLX4kUzqkEStBU8Vi
  + 87fa120...145e1e6 HEAD -> alice/1 (forced update)
 ```
 
+Notice that we used the `-o no-sync` push option to disable syncing after the push.
+
 ```
 $ git branch -r -vv
   rad/alice/1 145e1e6 Alice's amended commit

radicle-remote-helper/src/lib.rs

@@ -53,6 +53,12 @@ pub enum Error {
     List(#[from] list::Error),
 }
 
+#[derive(Debug, Default)]
+pub struct Options {
+    /// Don't sync after push.
+    no_sync: bool,
+}
+
 /// Run the radicle remote helper using the given profile.
 pub fn run(profile: radicle::Profile) -> Result<(), Error> {
     let url: Url = {
@@ -80,6 +86,7 @@ pub fn run(profile: radicle::Profile) -> Result<(), Error> {
 
     let stdin = io::stdin();
     let mut line = String::new();
+    let mut opts = Options::default();
 
     loop {
         let tokens = read_line(&stdin, &mut line)?;
@@ -94,8 +101,16 @@ pub fn run(profile: radicle::Profile) -> Result<(), Error> {
             ["option", "verbosity"] => {
                 println!("ok");
             }
-            ["option", "push-option", _opt] => {
+            ["option", "push-option", opt] => {
+                match *opt {
+                    "sync" => opts.no_sync = false,
+                    "no-sync" => opts.no_sync = true,
+                    _ => {
                         println!("unsupported");
+                        continue;
+                    }
+                }
+                println!("ok");
             }
             ["option", "progress", ..] => {
                 println!("unsupported");
@@ -115,6 +130,7 @@ pub fn run(profile: radicle::Profile) -> Result<(), Error> {
                     &stored,
                     &profile,
                     &stdin,
+                    &opts,
                 )
                 .map_err(Error::from);
             }

radicle-remote-helper/src/push.rs

@@ -19,7 +19,7 @@ use radicle::Profile;
 use radicle::{git, rad};
 use radicle_cli::terminal as cli;
 
-use crate::read_line;
+use crate::{read_line, Options};
 
 /// Default timeout for syncing to the network after a push.
 const DEFAULT_SYNC_TIMEOUT: time::Duration = time::Duration::from_secs(9);
@@ -117,6 +117,7 @@ pub fn run(
     stored: &storage::git::Repository,
     profile: &Profile,
     stdin: &io::Stdin,
+    opts: &Options,
 ) -> Result<(), Error> {
     // Don't allow push if either of these conditions is true:
     //
@@ -195,6 +196,7 @@ pub fn run(
         stored.sign_refs(&signer)?;
         stored.set_head()?;
 
+        if !opts.no_sync {
             // Connect to local node and announce refs to the network.
             // If our node is not running, we simply skip this step, as the
             // refs will be announced eventually, when the node restarts.
@@ -204,6 +206,7 @@ pub fn run(
                 sync(stored.id, node).ok();
             }
         }
+    }
 
     // Done.
     println!();