Add function for installing Josh

Author: Kobzol

Cargo.lock

@@ -8,3 +8,4 @@ anyhow = "1"
 clap = { version = "4", features = ["derive"] }
 toml = "0.8"
 serde = { version = "1", features = ["derive"] }
+which = "8"

Cargo.toml

@@ -1,19 +1,19 @@
 use anyhow::Context;
 use clap::Parser;
-use rustc_josh_sync::JoshConfig;
+use josh_sync::JoshConfig;
 
 const DEFAULT_CONFIG_PATH: &str = "josh-sync.toml";
 
 #[derive(clap::Parser)]
 struct Args {
     #[clap(subcommand)]
-    cmd: Command
+    cmd: Command,
 }
 
 #[derive(clap::Parser)]
 enum Command {
     /// Initialize a config file for this repository.
-    Init
+    Init,
 }
 
 fn main() -> anyhow::Result<()> {

src/bin/josh_sync.rs

@@ -0,0 +1,26 @@
+use crate::utils::check_output;
+use std::path::PathBuf;
+
+pub struct JoshProxy {
+    path: PathBuf,
+}
+
+impl JoshProxy {
+    /// Tries to figure out if `josh-proxy` is installed.
+    pub fn lookup() -> Option<Self> {
+        which::which("josh-proxy").ok().map(|path| Self { path })
+    }
+}
+
+fn install_josh() -> Option<JoshProxy> {
+    check_output(&[
+        "cargo",
+        "install",
+        "--locked",
+        "--git",
+        "https://github.com/josh-project/josh",
+        "--tag",
+        "r24.10.04",
+    ]);
+    JoshProxy::lookup()
+}

src/josh.rs

@@ -1,11 +1,14 @@
+pub mod josh;
+mod utils;
+
 #[derive(serde::Serialize, serde::Deserialize)]
 pub struct JoshConfig {
     #[serde(default = "default_org")]
     pub org: String,
     pub repo: String,
     /// Last SHA of rust-lang/rust that was pulled into this subtree.
     #[serde(default)]
-    pub upstream_sha: Option<String>
+    pub upstream_sha: Option<String>,
 }
 
 fn default_org() -> String {

src/lib.rs

@@ -0,0 +1,24 @@
+use std::process::{Command, Stdio};
+
+/// Run a command from an array, collecting its output.
+pub fn check_output<'a, Args: AsRef<[&'a str]>>(l: Args) -> String {
+    let l = l.as_ref();
+    check_output_cfg(l[0], |c| c.args(&l[1..]))
+}
+
+/// [`read`] with configuration. All shell helpers print the command and pass stderr.
+fn check_output_cfg(prog: &str, f: impl FnOnce(&mut Command) -> &mut Command) -> String {
+    let mut cmd = Command::new(prog);
+    cmd.stderr(Stdio::inherit());
+    f(&mut cmd);
+    eprintln!("+ {cmd:?}");
+    let out = cmd.output().expect("command failed");
+    let stdout = String::from_utf8_lossy(out.stdout.trim_ascii()).to_string();
+    if !out.status.success() {
+        panic!(
+            "Command `{cmd:?}` failed with exit code {:?}. STDOUT:\n{stdout}",
+            out.status.code()
+        );
+    }
+    stdout
+}