Add support for -w/--wrapper

.github/workflows/ci.yml

@@ -41,8 +41,10 @@ jobs:
       uses: dtolnay/rust-toolchain@stable
       with:
         toolchain: ${{ matrix.rust }}
-    - name: Install just
-      uses: taiki-e/install-action@just
+    - name: Setup homebrew
+      uses: Homebrew/actions/setup-homebrew@master
+    - name: Install hyperfine and just
+      run: brew install hyperfine just
     - name: Install rust-script
       run: cargo install --path .
     - name: Test examples

Cargo.toml

@@ -28,6 +28,7 @@ log = "0.4"
 pulldown-cmark = "0.9"
 regex = "1"
 sha1 = "0.10"
+shell-words = "1"
 tempfile = "3"
 toml = "0.7"
 

docs/README.md

@@ -107,6 +107,7 @@ Useful command-line arguments:
 - `--force`: Force the script to be rebuilt.  Useful if you want to force a recompile with a different toolchain.
 - `--package`: Generate the Cargo package and print the path to it - but don't compile or run it. Effectively "unpacks" the script into a Cargo package.
 - `--test`: Compile and run tests.
+- `--wrapper`: Add a wrapper around the executable. Can be used to run debugging with e.g. `rust-script --wrapper rust-lldb my-script.rs` or benchmarking with `rust-script --wrapper "hyperfine --runs 100" my-script.rs`
 
 ## Executable Scripts
 

examples/fib.ers

@@ -0,0 +1,13 @@
+#!/usr/bin/env rust-script
+
+fn fib(n: i32) -> i32 {
+  match n {
+    1 | 2 => 1,
+    _ => fib(n-1) + fib(n-2)
+  }
+}
+
+fn main() {
+  assert_eq!(fib(30), 832040);
+}
+

examples/test-examples.sh

@@ -11,3 +11,14 @@ assert_equals() {
 assert_equals "result: 3" "$(just -f justfile/Justfile)"
 assert_equals "hello, rust" "$(./hello.ers)"
 assert_equals "hello, rust" "$(./hello-without-main.ers)"
+
+HYPERFINE_OUTPUT=$(rust-script --wrapper "hyperfine --runs 99" fib.ers)
+
+case "$HYPERFINE_OUTPUT" in
+  *"99 runs"*)
+    ;;
+  *)
+    echo "Hyperfine output: $HYPERFINE_OUTPUT"
+    exit 1
+    ;;
+esac

src/arguments.rs

@@ -25,6 +25,7 @@ pub struct Args {
     pub install_file_association: bool,
     #[cfg(windows)]
     pub uninstall_file_association: bool,
+    pub wrapper: Option<String>,
 }
 
 impl Args {
@@ -75,7 +76,7 @@ impl Args {
                 .help("Base path for resolving dependencies")
                 .short('b')
                 .long("base-path")
-                .num_args(1..=1)
+                .num_args(1)
             )
             .arg(Arg::new("cargo-output")
                 .help("Show output from cargo when building")
@@ -163,6 +164,12 @@ impl Args {
                 .num_args(1)
                 // Benchmarking currently requires nightly:
                 .conflicts_with("bench")
+            )
+            .arg(Arg::new("wrapper")
+                .help("Wrapper injected before the command to run, e.g. 'rust-lldb' or 'hyperfine --runs 100'")
+                .long("wrapper")
+                .short('w')
+                .num_args(1)
             );
 
         #[cfg(windows)]
@@ -240,6 +247,7 @@ impl Args {
             install_file_association: m.get_flag("install-file-association"),
             #[cfg(windows)]
             uninstall_file_association: m.get_flag("uninstall-file-association"),
+            wrapper: m.get_one::<String>("wrapper").map(Into::into),
         }
     }
 }

src/main.rs

@@ -183,15 +183,14 @@ fn try_main() -> MainResult<i32> {
         return Ok(0);
     }
 
+    let mut cmd = action.command_to_execute(&args.script_args, args.wrapper)?;
     #[cfg(unix)]
     {
-        let mut cmd = action.cargo(&args.script_args)?;
         let err = cmd.exec();
         Err(MainError::from(err))
     }
     #[cfg(not(unix))]
     {
-        let mut cmd = action.cargo(&args.script_args)?;
         let exit_code = cmd.status().map(|st| st.code().unwrap_or(1))?;
         Ok(exit_code)
     }
@@ -332,7 +331,11 @@ impl InputAction {
         self.pkg_path.join("Cargo.toml")
     }
 
-    fn cargo(&self, script_args: &[String]) -> MainResult<Command> {
+    fn command_to_execute(
+        &self,
+        script_args: &[String],
+        wrapper: Option<String>,
+    ) -> MainResult<Command> {
         let release_mode = !self.debug && !matches!(self.build_kind, BuildKind::Bench);
 
         let built_binary_path = platform::binary_cache_path()
@@ -351,9 +354,25 @@ impl InputAction {
         let manifest_path = self.manifest_path();
 
         let execute_command = || {
-            let mut cmd = Command::new(&built_binary_path);
-            cmd.args(script_args.iter());
-            cmd
+            if let Some(wrapper) = wrapper {
+                let wrapper_words = shell_words::split(&wrapper).unwrap();
+                if wrapper_words.is_empty() {
+                    return MainResult::Err(MainError::OtherBorrowed(
+                        "The wrapper cannot be empty",
+                    ));
+                }
+                let mut cmd = Command::new(&wrapper_words[0]);
+                if wrapper_words.len() > 1 {
+                    cmd.args(wrapper_words[1..].iter());
+                }
+                cmd.arg(&built_binary_path);
+                cmd.args(script_args.iter());
+                Ok(cmd)
+            } else {
+                let mut cmd = Command::new(&built_binary_path);
+                cmd.args(script_args.iter());
+                Ok(cmd)
+            }
         };
 
         if matches!(self.build_kind, BuildKind::Normal) && !self.force_compile {
@@ -376,7 +395,7 @@ impl InputAction {
                                 && built_binary_time.cmp(&manifest_mtime).is_ge()
                             {
                                 debug!("Keeping old binary");
-                                return Ok(execute_command());
+                                return execute_command();
                             } else {
                                 debug!("Old binary too old - rebuilding");
                             }
@@ -423,7 +442,7 @@ impl InputAction {
 
         if matches!(self.build_kind, BuildKind::Normal) {
             if cmd.status()?.code() == Some(0) {
-                cmd = execute_command();
+                cmd = execute_command()?;
             } else {
                 return Err(MainError::OtherOwned("Could not execute cargo".to_string()));
             }