fix(shell): run sidecar with dots in filename, closes #2310

.changes/fix-sidecar-dots.md

@@ -0,0 +1,6 @@
+---
+"shell": patch
+"shell-js": patch
+---
+
+Fix sidecar with dots in the filename not working on Windows.

plugins/shell/src/commands.rs

@@ -115,7 +115,12 @@ fn prepare_cmd<R: Runtime>(
     let mut command = if options.sidecar {
         let program = PathBuf::from(program);
         let program_as_string = program.display().to_string();
-        let program_no_ext_as_string = program.with_extension("").display().to_string();
+        let has_extension = program.extension().is_some_and(|ext| ext == "exe");
+        let program_no_ext_as_string = if has_extension {
+            program.with_extension("").display().to_string()
+        } else {
+            program_as_string.clone()
+        };
         let configured_sidecar = window
             .config()
             .bundle

plugins/shell/src/process/mod.rs

@@ -118,9 +118,23 @@ pub struct Output {
 fn relative_command_path(command: &Path) -> crate::Result<PathBuf> {
     match platform::current_exe()?.parent() {
         #[cfg(windows)]
-        Some(exe_dir) => Ok(exe_dir.join(command).with_extension("exe")),
+        Some(exe_dir) => {
+            let mut command_path = exe_dir.join(command);
+            let already_exe = command_path.extension().is_some_and(|ext| ext == "exe");
+            if !already_exe {
+                // do not use with_extension to retain dots in the command filename
+                command_path.as_mut_os_string().push(".exe");
+            }
+            Ok(command_path)
+        }
         #[cfg(not(windows))]
-        Some(exe_dir) => Ok(exe_dir.join(command)),
+        Some(exe_dir) => {
+            let mut command_path = exe_dir.join(command);
+            if command_path.extension().is_some_and(|ext| ext == "exe") {
+                command_path.set_extension("");
+            }
+            Ok(command_path)
+        }
         None => Err(crate::Error::CurrentExeHasNoParent),
     }
 }
@@ -133,6 +147,10 @@ impl From<Command> for StdCommand {
 
 impl Command {
     pub(crate) fn new<S: AsRef<OsStr>>(program: S) -> Self {
+        log::debug!(
+            "Creating sidecar {}",
+            program.as_ref().to_str().unwrap_or("")
+        );
         let mut command = StdCommand::new(program);
 
         command.stdout(Stdio::piped());
@@ -451,9 +469,33 @@ fn spawn_pipe_reader<F: Fn(Vec<u8>) -> CommandEvent + Send + Copy + 'static>(
 // tests for the commands functions.
 #[cfg(test)]
 mod tests {
-    #[cfg(not(windows))]
     use super::*;
 
+    #[test]
+    fn relative_command_path_resolves() {
+        let cwd_parent = platform::current_exe()
+            .unwrap()
+            .parent()
+            .unwrap()
+            .to_owned();
+        assert_eq!(
+            relative_command_path(Path::new("Tauri.Example")).unwrap(),
+            cwd_parent.join(if cfg!(windows) {
+                "Tauri.Example.exe"
+            } else {
+                "Tauri.Example"
+            })
+        );
+        assert_eq!(
+            relative_command_path(Path::new("Tauri.Example.exe")).unwrap(),
+            cwd_parent.join(if cfg!(windows) {
+                "Tauri.Example.exe"
+            } else {
+                "Tauri.Example"
+            })
+        );
+    }
+
     #[cfg(not(windows))]
     #[test]
     fn test_cmd_spawn_output() {