usable backend for terminal launch

src-tauri/src/config.rs

@@ -1,4 +1,5 @@
 use std::net::Ipv4Addr;
+use std::ffi::OsString;
 use std::path::PathBuf;
 
 use auto_launch::AutoLaunchBuilder;
@@ -15,7 +16,7 @@ pub struct TermConfig {
     // we call it exec because it isn't always the actual path,
     // in some cases it's just the name and relies on path-searching
     pub exec: PathBuf,
-    pub args: Vec<String>,
+    pub args: Vec<OsString>,
 }
 
 
@@ -31,7 +32,8 @@ pub struct AppConfig {
     pub start_minimized: bool,
     #[serde(default = "default_start_on_login")]
     pub start_on_login: bool,
-    pub terminal: Option<TermConfig>,
+    #[serde(default = "default_term_config")]
+    pub terminal: TermConfig,
 }
 
 
@@ -43,7 +45,7 @@ impl Default for AppConfig {
             rehide_ms: default_rehide_ms(),
             start_minimized: default_start_minimized(),
             start_on_login: default_start_on_login(),
-            terminal: None,
+            terminal: default_term_config(),
         }
     }
 }
@@ -128,6 +130,44 @@ fn default_listen_port() -> u16 {
     }
 }
 
+
+fn default_term_config() -> TermConfig {
+    #[cfg(windows)]
+    {
+        if let Ok(path) = which::which("pwsh.exe") {
+            return TermConfig {
+                name: exe.into(),
+                exec: "conhost.exe".into(),
+                args: vec![path.into_os_string()]
+            };
+        }
+        return TermConfig {
+            name: "powershell.exe".into(),
+            exec: "conhost.exe".into(),
+            args: vec!["powershell.exe".into()]
+        };
+    }
+
+    #[cfg(unix)]
+    {
+        for bin in ["gnome-terminal", "konsole"] {
+            if let Ok(_) = which::which(bin) {
+                return TermConfig {
+                    name: bin.into(),
+                    exec: bin.into(),
+                    args: vec![],
+                }
+            }
+        }
+        return TermConfig {
+            name: "gnome-terminal".into(),
+            exec: "gnome-terminal".into(),
+            args: vec![],
+        };
+    }
+}
+
+
 fn default_listen_addr() -> Ipv4Addr { Ipv4Addr::LOCALHOST }
 fn default_rehide_ms() -> u64 { 1000 }
 // start minimized and on login only in production mode

src-tauri/src/credentials.rs

@@ -81,6 +81,16 @@ impl Session {
             Session::Empty => Err(GetSessionError::CredentialsEmpty),
         }
     }
+
+    pub fn try_get(
+        &self
+    ) -> Result<(&BaseCredentials, &SessionCredentials), GetCredentialsError> {
+        match self {
+            Self::Empty => Err(GetCredentialsError::Empty),
+            Self::Locked(_) => Err(GetCredentialsError::Locked),
+            Self::Unlocked{ ref base, ref session } => Ok((base, session))
+        }
+    }
 }
 
 

src-tauri/src/errors.rs

@@ -1,5 +1,6 @@
 use std::error::Error;
 use std::convert::AsRef;
+use std::ffi::OsString;
 use std::sync::mpsc;
 use strum_macros::AsRefStr;
 
@@ -216,7 +217,7 @@ pub enum RequestError {
 }
 
 
-// Errors encountered while running a subprocess (via creddy exec)
+// Errors encountered while running a subprocess via creddy exec
 #[derive(Debug, ThisError, AsRefStr)]
 pub enum ExecError {
     #[error("Please specify a command")]
@@ -237,6 +238,18 @@ pub enum CliError {
 }
 
 
+// Errors encountered while trying to launch a child process
+#[derive(Debug, ThisError, AsRefStr)]
+pub enum LaunchError {
+    #[error("Executable not found: {0:?}")]
+    ExeNotFound(OsString),
+    #[error("Failed to execute command: {0}")]
+    ExecutionFailed(#[from] std::io::Error),
+    #[error(transparent)]
+    GetCredentials(#[from] GetCredentialsError),
+}
+
+
 // =========================
 // Serialize implementations
 // =========================
@@ -327,3 +340,18 @@ impl Serialize for UnlockError {
         map.end()
     }
 }
+
+
+impl Serialize for LaunchError {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("code", self.as_ref())?;
+        map.serialize_entry("msg", &format!("{self}"))?;
+
+        match self {
+            LaunchError::GetCredentials(src) => map.serialize_entry("source", &src)?,
+            _ => serialize_upstream_err(self, &mut map)?,
+        }
+        map.end()
+    }
+}

src-tauri/src/ipc.rs

@@ -82,9 +82,6 @@ pub async fn save_config(config: AppConfig, app_state: State<'_, AppState>) -> R
 
 
 #[tauri::command]
-pub async fn launch_terminal(base: bool) -> bool {
-    match terminal::launch(base).await {
-        Ok(_) => true,
-        Err(_) => false,
-    }
+pub async fn launch_terminal(base: bool) -> Result<(), LaunchError> {
+    terminal::launch(base).await
 }

src-tauri/src/terminal.rs

@@ -3,39 +3,25 @@ use std::process::Command;
 use tauri::Manager;
 
 use crate::app::APP;
-use crate::config::TermConfig;
-use crate::credentials::Session;
 use crate::errors::*;
 use crate::state::AppState;
 
 
-pub async fn launch(use_base: bool) -> Result<(), ExecError> {
-    // we may have multiple candidates, because we might be on unix and
-    // we don't have a good way of detecting for sure what default to use
+pub async fn launch(use_base: bool) -> Result<(), LaunchError> {
     let state = APP.get().unwrap().state::<AppState>();
-    let config = state.config.read().await;
-    let _ = match config.terminal {
-        Some(ref term) => launch_term(term, use_base).await,
-        None => launch_default(use_base).await,
-    }?;
-    Ok(())
-}
-
-
-async fn launch_term(term: &TermConfig, use_base: bool) -> Result<(), std::io::Error> {
     // do all this in a block so we don't hold the lock any longer than necessary
-    let mut cmd = Command::new(&term.exec);
-    cmd.args(&term.args);
+    let mut cmd = {
+        let config = state.config.read().await;
+        let mut cmd = Command::new(&config.terminal.exec);
+        cmd.args(&config.terminal.args);
+        cmd
+    };
+
+    // similarly
     {
-        // note: if called from launch(), there is already a lock being held on state.config
-        // don't read that here or we will deadlock
         let state = APP.get().unwrap().state::<AppState>();
         let app_session = state.session.read().await;
-        let (base_creds, session_creds) = match *app_session {
-            Session::Locked(_) | Session::Empty => todo!(),
-            Session::Unlocked{ref base, ref session} => (base, session),
-        };
-
+        let (base_creds, session_creds) = app_session.try_get()?;
         if use_base {
             cmd.env("AWS_ACCESS_KEY_ID", &base_creds.access_key_id);
             cmd.env("AWS_SECRET_ACCESS_KEY", &base_creds.secret_access_key);
@@ -47,51 +33,16 @@ async fn launch_term(term: &TermConfig, use_base: bool) -> Result<(), std::io::E
         }
     }
 
-    let _ = cmd.spawn()?;
-    Ok(())
-}
-
-
-async fn launch_default(use_base: bool) -> Result<(), std::io::Error> {
-    let defaults = default_terms();
-    let last_idx = defaults.len() - 1;
-    for (i, candidate) in defaults.iter().enumerate() {
-        match launch_term(candidate, use_base).await {
-            Ok(_) => return Ok(()),
-            Err(e) => {
-                if std::io::ErrorKind::NotFound == e.kind() && i < last_idx {
-                    continue;
-                }
-                return Err(e);
+    match cmd.spawn() {
+        Ok(_) => Ok(()),
+        Err(e) => {
+            use std::io::ErrorKind::*;
+            if let NotFound = e.kind() {
+                Err(LaunchError::ExeNotFound(cmd.get_program().to_owned()))
+            }
+            else {
+                Err(LaunchError::from(e))
             }
         }
     }
-    // we only continue the loop if there are further iterations left, so this is safe
-    unreachable!() 
 }
-
-
-pub fn default_terms() -> Vec<TermConfig> {
-    #[cfg(windows)]
-    return vec![
-        TermConfig {
-            name: "powershell.exe".into(),
-            exec: "conhost.exe".into(),
-            args: vec!["powershell.exe".into()]
-        }
-    ];
-
-    #[cfg(unix)]
-    return vec![
-        TermConfig {
-            name: "gnome-terminal".into(),
-            exec: "gnome-terminal".into(),
-            args: vec![],
-        },
-        TermConfig {
-            name: "konsole".into(), 
-            exec: "konsole".into(),
-            args: vec![],
-        },
-    ];
-}