errors: Don't unwrap in `server::terminal_bytes` (#1876)

* server/terminal_bytes: Don't unwrap

and return `Result`s instead, where appropriate.

* changelog: Add PR #1876

Don't unwrap in `zellij_server::terminal_bytes`.

3 files changed, 40 insertions, 18 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 583ba8741..a37740d93 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * debugging: Remove calls to unwrap in `zellij_server::ui::*` (https://github.com/zellij-org/zellij/pull/1870)
 * debugging: Remove calls to unwrap in `zellij_server::pty_writer` (https://github.com/zellij-org/zellij/pull/1872)
 * docs(example): update the format of the themes for the example directory (https://github.com/zellij-org/zellij/pull/1877)
+* debugging: Remove calls to unwrap in `zellij_server::terminal_bytes` (https://github.com/zellij-org/zellij/pull/1876)
 
 ## [0.32.0] - 2022-10-25
 
diff --git a/zellij-server/src/pty.rs b/zellij-server/src/pty.rs
index 03f87fd7a..bb5beb5dd 100644
--- a/zellij-server/src/pty.rs
+++ b/zellij-server/src/pty.rs
@@ -455,20 +455,23 @@ impl Pty {
             .ok_or_else(|| SpawnTerminalError::GenericSpawnError("os input is none"))?
             .spawn_terminal(terminal_action, quit_cb, self.default_editor.clone())?;
         let terminal_bytes = task::spawn({
-            let err_context = || format!("failed to run async task for terminal {terminal_id}");
+            let err_context =
+                |terminal_id: u32| format!("failed to run async task for terminal {terminal_id}");
             let senders = self.bus.senders.clone();
             let os_input = self
                 .bus
                 .os_input
                 .as_ref()
-                .with_context(err_context)
+                .with_context(|| err_context(terminal_id))
                 .fatal()
                 .clone();
             let debug_to_file = self.debug_to_file;
             async move {
                 TerminalBytes::new(pid_primary, senders, os_input, debug_to_file, terminal_id)
                     .listen()
-                    .await;
+                    .await
+                    .with_context(|| err_context(terminal_id))
+                    .fatal();
             }
         });
 
@@ -657,7 +660,9 @@ impl Pty {
                                 terminal_id,
                             )
                             .listen()
-                            .await;
+                            .await
+                            .context("failed to spawn terminals for layout")
+                            .fatal();
                         }
                     });
                     self.task_handles.insert(terminal_id, terminal_bytes);
@@ -758,20 +763,23 @@ impl Pty {
                     .ok_or_else(|| SpawnTerminalError::GenericSpawnError("os input is none"))?
                     .re_run_command_in_terminal(id, run_command, quit_cb)?;
                 let terminal_bytes = task::spawn({
-                    let err_context = || format!("failed to run async task for pane {pane_id:?}");
+                    let err_context =
+                        |pane_id| format!("failed to run async task for pane {pane_id:?}");
                     let senders = self.bus.senders.clone();
                     let os_input = self
                         .bus
                         .os_input
                         .as_ref()
-                        .with_context(err_context)
+                        .with_context(|| err_context(pane_id))
                         .fatal()
                         .clone();
                     let debug_to_file = self.debug_to_file;
                     async move {
                         TerminalBytes::new(pid_primary, senders, os_input, debug_to_file, id)
                             .listen()
-                            .await;
+                            .await
+                            .with_context(|| err_context(pane_id))
+                            .fatal();
                     }
                 });
 
diff --git a/zellij-server/src/terminal_bytes.rs b/zellij-server/src/terminal_bytes.rs
index 4fa1e4568..d313ec5d1 100644
--- a/zellij-server/src/terminal_bytes.rs
+++ b/zellij-server/src/terminal_bytes.rs
@@ -10,7 +10,7 @@ use std::{
 };
 use zellij_utils::{
     async_std,
-    errors::{get_current_ctx, ContextType},
+    errors::{get_current_ctx, prelude::*, ContextType},
     logging::debug_to_file,
 };
 
@@ -63,7 +63,7 @@ impl TerminalBytes {
             last_render: Instant::now(),
         }
     }
-    pub async fn listen(&mut self) {
+    pub async fn listen(&mut self) -> Result<()> {
         // This function reads bytes from the pty and then sends them as
         // ScreenInstruction::PtyBytes to screen to be parsed there
         // We also send a separate instruction to Screen to render as ScreenInstruction::Render
@@ -75,6 +75,8 @@ impl TerminalBytes {
         // only send a render instruction sparingly, giving screen time to process bytes and render
         // while still allowing the user to see an indication that things are happening (the
         // sparing render instructions)
+        let err_context = || "failed to listen for bytes from PTY".to_string();
+
         let mut err_ctx = get_current_ctx();
         err_ctx.add_call(ContextType::AsyncTask);
         let mut buf = [0u8; 65536];
@@ -82,8 +84,10 @@ impl TerminalBytes {
             match self.deadline_read(&mut buf).await {
                 ReadResult::Ok(0) | ReadResult::Err(_) => break, // EOF or error
                 ReadResult::Timeout => {
-                    let time_to_send_render =
-                        self.async_send_to_screen(ScreenInstruction::Render).await;
+                    let time_to_send_render = self
+                        .async_send_to_screen(ScreenInstruction::Render)
+                        .await
+                        .with_context(err_context)?;
                     self.update_render_send_time(time_to_send_render);
                     // next read does not need a deadline as we just rendered everything
                     self.render_deadline = None;
@@ -98,11 +102,14 @@ impl TerminalBytes {
                         self.terminal_id,
                         bytes.to_vec(),
                     ))
-                    .await;
+                    .await
+                    .with_context(err_context)?;
                     if !self.backed_up {
                         // we're not backed up, let's send an immediate render instruction
-                        let time_to_send_render =
-                            self.async_send_to_screen(ScreenInstruction::Render).await;
+                        let time_to_send_render = self
+                            .async_send_to_screen(ScreenInstruction::Render)
+                            .await
+                            .with_context(err_context)?;
                         self.update_render_send_time(time_to_send_render);
                         self.last_render = Instant::now();
                     }
@@ -113,16 +120,22 @@ impl TerminalBytes {
                 },
             }
         }
-        self.async_send_to_screen(ScreenInstruction::Render).await;
+        self.async_send_to_screen(ScreenInstruction::Render)
+            .await
+            .with_context(err_context)?;
+        Ok(())
     }
-    async fn async_send_to_screen(&self, screen_instruction: ScreenInstruction) -> Duration {
+    async fn async_send_to_screen(
+        &self,
+        screen_instruction: ScreenInstruction,
+    ) -> Result<Duration> {
         // returns the time it blocked the thread for
         let sent_at = Instant::now();
         let senders = self.senders.clone();
         task::spawn_blocking(move || senders.send_to_screen(screen_instruction))
             .await
-            .unwrap();
-        sent_at.elapsed()
+            .context("failed to async-send to screen")?;
+        Ok(sent_at.elapsed())
     }
     fn update_render_send_time(&mut self, time_to_send_render: Duration) {
         match self.minimum_render_send_time.as_mut() {