fix(downloads): open and reveal files on every platform

crates/ely_app/src/services/download_files.rs

@@ -27,17 +27,23 @@ pub enum DownloadFileError {
 impl DownloadFileAction {
     pub fn run(self, path: &Path) -> Result<(), DownloadFileError> {
         ensure_regular_file(path)?;
-        let status =
+        let mut command = self.command(path);
-            self.command(path).status().map_err(|source| DownloadFileError::LaunchFailed {
+        let launch_failed = |source| DownloadFileError::LaunchFailed {
             action: self.label(),
             path: path.to_path_buf(),
             source,
-            })?;
+        };
 
+        // Windows Explorer returns a nonzero exit code even when it opens
+        // the folder, so for Reveal there we only require that it launched.
+        if !self.exit_status_is_meaningful() {
+            return command.spawn().map(|_| ()).map_err(launch_failed);
+        }
+
+        let status = command.status().map_err(launch_failed)?;
         if status.success() {
             return Ok(());
         }
-
         Err(DownloadFileError::CommandFailed {
             action: self.label(),
             path: path.to_path_buf(),
@@ -45,18 +51,51 @@ impl DownloadFileAction {
         })
     }
 
+    /// The OS launcher for the current platform: `open` on macOS,
+    /// `cmd /C start` / `explorer /select,` on Windows, `xdg-open` on
+    /// Linux and other Unixes (revealing the containing folder, since
+    /// there is no portable "select in file manager").
     fn command(self, path: &Path) -> Command {
+        #[cfg(target_os = "macos")]
+        {
             let mut command = Command::new("/usr/bin/open");
+            match self {
+                Self::Open => command.arg(path),
+                Self::Reveal => command.arg("-R").arg(path),
+            };
+            command
+        }
+        #[cfg(target_os = "windows")]
+        {
             match self {
                 Self::Open => {
-                command.arg(path);
+                    let mut command = Command::new("cmd");
+                    command.arg("/C").arg("start").arg("").arg(path);
+                    command
                 }
                 Self::Reveal => {
-                command.arg("-R").arg(path);
+                    let mut select = std::ffi::OsString::from("/select,");
-            }
+                    select.push(path);
-        }
+                    let mut command = Command::new("explorer");
+                    command.arg(select);
                     command
                 }
+            }
+        }
+        #[cfg(not(any(target_os = "macos", target_os = "windows")))]
+        {
+            let mut command = Command::new("xdg-open");
+            match self {
+                Self::Open => command.arg(path),
+                Self::Reveal => command.arg(path.parent().unwrap_or(path)),
+            };
+            command
+        }
+    }
+
+    fn exit_status_is_meaningful(self) -> bool {
+        !(cfg!(target_os = "windows") && matches!(self, Self::Reveal))
+    }
 
     pub fn label(self) -> &'static str {
         match self {
@@ -72,3 +111,64 @@ fn ensure_regular_file(path: &Path) -> Result<(), DownloadFileError> {
         Ok(_) | Err(_) => Err(DownloadFileError::FileUnavailable { path: path.to_path_buf() }),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn program_and_args(action: DownloadFileAction, path: &Path) -> (String, Vec<String>) {
+        let command = action.command(path);
+        let program = command.get_program().to_string_lossy().into_owned();
+        let args = command.get_args().map(|arg| arg.to_string_lossy().into_owned()).collect();
+        (program, args)
+    }
+
+    #[test]
+    fn open_launches_the_platform_handler_for_the_file() {
+        let (program, args) = program_and_args(DownloadFileAction::Open, Path::new("/tmp/a.pdf"));
+        #[cfg(target_os = "macos")]
+        {
+            assert_eq!(program, "/usr/bin/open");
+            assert_eq!(args, vec!["/tmp/a.pdf"]);
+        }
+        #[cfg(target_os = "windows")]
+        {
+            assert_eq!(program, "cmd");
+            assert_eq!(args, vec!["/C", "start", "", "/tmp/a.pdf"]);
+        }
+        #[cfg(not(any(target_os = "macos", target_os = "windows")))]
+        {
+            assert_eq!(program, "xdg-open");
+            assert_eq!(args, vec!["/tmp/a.pdf"]);
+        }
+    }
+
+    #[test]
+    fn reveal_targets_the_file_or_its_containing_folder() {
+        let (program, args) = program_and_args(DownloadFileAction::Reveal, Path::new("/tmp/a.pdf"));
+        #[cfg(target_os = "macos")]
+        {
+            assert_eq!(program, "/usr/bin/open");
+            assert_eq!(args, vec!["-R", "/tmp/a.pdf"]);
+        }
+        #[cfg(target_os = "windows")]
+        {
+            assert_eq!(program, "explorer");
+            assert_eq!(args, vec!["/select,/tmp/a.pdf"]);
+        }
+        #[cfg(not(any(target_os = "macos", target_os = "windows")))]
+        {
+            assert_eq!(program, "xdg-open");
+            assert_eq!(args, vec!["/tmp"]);
+        }
+    }
+
+    #[test]
+    fn only_windows_reveal_skips_the_exit_status_check() {
+        assert!(DownloadFileAction::Open.exit_status_is_meaningful());
+        assert_eq!(
+            DownloadFileAction::Reveal.exit_status_is_meaningful(),
+            !cfg!(target_os = "windows"),
+        );
+    }
+}