From 91f836884410285fb3adf151ba60057df9e8aeb8 Mon Sep 17 00:00:00 2001
From: Chris Olszewski <chris.olszewski@vercel.com>
Date: Tue, 13 Aug 2024 13:55:52 -0400
Subject: [PATCH] fix(tui): build new virtual terminal on resize

---
 crates/turborepo-ui/src/tui/app.rs         |  2 +-
 crates/turborepo-ui/src/tui/term_output.rs | 20 +++++++++++++++++---
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/crates/turborepo-ui/src/tui/app.rs b/crates/turborepo-ui/src/tui/app.rs
index ef72122773c5b..0c63d7f644db6 100644
--- a/crates/turborepo-ui/src/tui/app.rs
+++ b/crates/turborepo-ui/src/tui/app.rs
@@ -400,7 +400,7 @@ impl<W: Write> App<W> {
     #[tracing::instrument(skip(self, output))]
     pub fn process_output(&mut self, task: &str, output: &[u8]) -> Result<(), Error> {
         let task_output = self.tasks.get_mut(task).unwrap();
-        task_output.parser.process(output);
+        task_output.process(output);
         Ok(())
     }
 }
diff --git a/crates/turborepo-ui/src/tui/term_output.rs b/crates/turborepo-ui/src/tui/term_output.rs
index 0ad2b1ee1d0fe..2eb2e52cf7da3 100644
--- a/crates/turborepo-ui/src/tui/term_output.rs
+++ b/crates/turborepo-ui/src/tui/term_output.rs
@@ -1,4 +1,4 @@
-use std::io::Write;
+use std::{io::Write, mem};
 
 use turborepo_vt100 as vt100;
 
@@ -8,7 +8,10 @@ use super::{
     Error,
 };
 
+const SCROLLBACK_LEN: usize = 1024;
+
 pub struct TerminalOutput<W> {
+    output: Vec<u8>,
     pub parser: vt100::Parser,
     pub stdin: Option<W>,
     pub status: Option<String>,
@@ -27,7 +30,8 @@ enum LogBehavior {
 impl<W> TerminalOutput<W> {
     pub fn new(rows: u16, cols: u16, stdin: Option<W>) -> Self {
         Self {
-            parser: vt100::Parser::new(rows, cols, 1024),
+            output: Vec::new(),
+            parser: vt100::Parser::new(rows, cols, SCROLLBACK_LEN),
             stdin,
             status: None,
             output_logs: None,
@@ -47,9 +51,19 @@ impl<W> TerminalOutput<W> {
         self.parser.screen().size()
     }
 
+    pub fn process(&mut self, bytes: &[u8]) {
+        self.parser.process(bytes);
+        self.output.extend_from_slice(bytes);
+    }
+
     pub fn resize(&mut self, rows: u16, cols: u16) {
         if self.parser.screen().size() != (rows, cols) {
-            self.parser.screen_mut().set_size(rows, cols);
+            let scrollback = self.parser.screen().scrollback();
+            let mut new_parser = vt100::Parser::new(rows, cols, SCROLLBACK_LEN);
+            new_parser.process(&self.output);
+            new_parser.screen_mut().set_scrollback(scrollback);
+            // Completely swap out the old vterm with a new correctly sized one
+            mem::swap(&mut self.parser, &mut new_parser);
         }
     }