ui: Do not clip strings for unattended output

String clipping is only useful if we're rendering the UI. If output is
unattended or user has requested UI disabled, no need to clip output.

Author: danobi

src/ui.rs

@@ -105,10 +105,22 @@ impl Stage {
             // If output is attended, we do custom window with our own styling.
             // Therefore, we need to strip away any existing formatting.
             let stripped = strip_ansi_codes(trimmed_line);
+
+            // Clip output to fit in terminal.
+            //
+            // Note this _does_not_ handle characters that expand to multiple columns,
+            // like tabs or other fancy unicode. This is known to corrupt UI visuals. There
+            // is no real solution to this without doing a mini terminal emulator AFAIK.
+            // The workaround is to set VMTEST_NO_UI.
+            let width = self.term.size_checked().map(|(_, w)| w).unwrap_or(u16::MAX);
+            let clipped = truncate_str(&stripped, width as usize, "...");
+
+            // Apply styling
             let styled = match &custom {
-                Some(s) => s.apply_to(stripped),
-                None => style(stripped).dim(),
+                Some(s) => s.apply_to(clipped),
+                None => style(clipped).dim(),
             };
+
             styled.to_string()
         } else {
             // If output is not attended, we do pass through
@@ -118,16 +130,9 @@ impl Stage {
         // Unwrap should never fail b/c we're sizing with `min()`
         let window = self.lines.windows(self.window_size()).last().unwrap();
 
-        // Get terminal width, if any
-        let width = match self.term.size_checked() {
-            Some((_, w)) => w,
-            _ => u16::MAX,
-        };
-
         // Print visible lines
         for line in window {
-            let clipped = truncate_str(line, width as usize - 3, "...");
-            self.term.write_line(&format!("{}", clipped)).unwrap();
+            self.term.write_line(line).unwrap();
         }
     }