Quote arguments when executing in a shell (#118)

* Quote arguments when executing in a shell

Fixes #107

* Parse quotes in `tmux_arguments`

This makes it possible to encode spaces in arguments. Maybe the config
value should be an array instead?

* Print error causes

Co-authored-by: Thomas Schönauer <37108907+DottoDev@users.noreply.github.com>

Cargo.lock

@@ -1606,6 +1606,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
 
+[[package]]
+name = "shell-words"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24188a676b6ae68c3b2cb3a01be17fbf7240ce009799bb56d5b1409051e78fde"
+
 [[package]]
 name = "shellexpand"
 version = "2.1.2"
@@ -1943,6 +1949,7 @@ dependencies = [
  "self_update",
  "semver",
  "serde",
+ "shell-words",
  "shellexpand",
  "strum 0.24.1",
  "sys-info",

Cargo.toml

@@ -44,6 +44,7 @@ futures = "0.3"
 regex = "1.5"
 sys-info = "0.9"
 semver = "1.0"
+shell-words = "1.1.0"
 
 [target.'cfg(target_os = "macos")'.dependencies]
 notify-rust = "4.5"

src/config.rs

@@ -4,7 +4,6 @@ use std::fs::write;
 use std::path::PathBuf;
 use std::process::Command;
 use std::{env, fs};
-
 use anyhow::Result;
 use clap::{ArgEnum, Parser};
 use directories::BaseDirs;
@@ -626,8 +625,16 @@ impl Config {
     }
 
     /// Extra Tmux arguments
-    pub fn tmux_arguments(&self) -> &Option<String> {
+    pub fn tmux_arguments(&self) -> anyhow::Result<Vec<String>> {
-        &self.config_file.tmux_arguments
+        let args = &self.config_file.tmux_arguments.as_deref().unwrap_or_default();
+        shell_words::split(args)
+            // The only time the parse failed is in case of a missing close quote.
+            // The error message looks like this:
+            //     Error: Failed to parse `tmux_arguments`: `'foo`
+            //
+            //     Caused by:
+            //         missing closing quote
+            .with_context(|| format!("Failed to parse `tmux_arguments`: `{args}`"))
     }
 
     /// Prompt for a key before exiting

src/executor.rs

@@ -194,11 +194,12 @@ impl DryCommand {
         print!(
             "Dry running: {} {}",
             self.program.to_string_lossy(),
+            shell_words::join(
                 self.args
                     .iter()
                     .map(|a| String::from(a.to_string_lossy()))
                     .collect::<Vec<String>>()
-                .join(" ")
+            )
         );
         match &self.directory {
             Some(dir) => println!(" in {}", dir.to_string_lossy()),

src/main.rs

@@ -79,7 +79,7 @@ fn run() -> Result<()> {
     if config.run_in_tmux() && env::var("TOPGRADE_INSIDE_TMUX").is_err() {
         #[cfg(unix)]
         {
-            tmux::run_in_tmux(config.tmux_arguments());
+            tmux::run_in_tmux(config.tmux_arguments()?);
         }
     }
 
@@ -524,7 +524,10 @@ fn main() {
                     .is_some());
 
             if !skip_print {
-                println!("Error: {}", error);
+                // The `Debug` implementation of `anyhow::Result` prints a multi-line
+                // error message that includes all the 'causes' added with
+                // `.with_context(...)` calls.
+                println!("Error: {:?}", error);
             }
             exit(1);
         }

src/steps/powershell.rs

@@ -79,6 +79,7 @@ impl Powershell {
         println!("Updating modules...");
         ctx.run_type()
             .execute(powershell)
+            // This probably doesn't need `shell_words::join`.
             .args(["-NoProfile", "-Command", &cmd.join(" ")])
             .check_run()
     }

src/steps/remote/ssh.rs

@@ -24,7 +24,7 @@ pub fn ssh_step(ctx: &ExecutionContext, hostname: &str) -> Result<()> {
         #[cfg(unix)]
         {
             prepare_async_ssh_command(&mut args);
-            crate::tmux::run_command(ctx, &args.join(" "))?;
+            crate::tmux::run_command(ctx, &shell_words::join(args))?;
             Err(SkipStep(String::from("Remote Topgrade launched in Tmux")).into())
         }
 

src/steps/tmux.rs

@@ -29,12 +29,10 @@ struct Tmux {
 }
 
 impl Tmux {
-    fn new(args: &Option<String>) -> Self {
+    fn new(args: Vec<String>) -> Self {
         Self {
             tmux: which("tmux").expect("Could not find tmux"),
-            args: args
+            args: if args.is_empty() { None } else { Some(args) },
-                .as_ref()
-                .map(|args| args.split_whitespace().map(String::from).collect()),
         }
     }
 
@@ -75,7 +73,7 @@ impl Tmux {
     }
 }
 
-pub fn run_in_tmux(args: &Option<String>) -> ! {
+pub fn run_in_tmux(args: Vec<String>) -> ! {
     let command = {
         let mut command = vec![
             String::from("env"),
@@ -83,10 +81,10 @@ pub fn run_in_tmux(args: &Option<String>) -> ! {
             String::from("TOPGRADE_INSIDE_TMUX=1"),
         ];
         command.extend(env::args());
-        command.join(" ")
+        shell_words::join(command)
     };
 
-    let tmux = Tmux::new(args);
+    let tmux = Tmux::new(args.clone());
 
     if !tmux.has_session("topgrade").expect("Error detecting a tmux session") {
         tmux.new_session("topgrade").expect("Error creating a tmux session");
@@ -108,7 +106,7 @@ pub fn run_in_tmux(args: &Option<String>) -> ! {
 }
 
 pub fn run_command(ctx: &ExecutionContext, command: &str) -> Result<()> {
-    Tmux::new(ctx.config().tmux_arguments())
+    Tmux::new(ctx.config().tmux_arguments()?)
         .build()
         .args(["new-window", "-a", "-t", "topgrade:1", command])
         .env_remove("TMUX")