Deno.stderr.writeSync() may not wright full error message buffer in one go for very long message

Error in Jupyter Notebook can have very long backtrace which where truncated in console logger, but not in file logger.

Context #12238

Author: cderv

news/changelog-1.7.md

@@ -146,6 +146,7 @@ All changes included in 1.7:
 - ([#11803](https://github.com/quarto-dev/quarto-cli/pull/11803)): Added a new CLI command `quarto call`. First users of this interface are the new `quarto call engine julia ...` subcommands.
 - ([#12338](https://github.com/quarto-dev/quarto-cli/issues/12338)): Add an additional workaround for the SCSS parser used in color variable extraction.
 - ([#12369](https://github.com/quarto-dev/quarto-cli/pull/12369)): `quarto preview` correctly throws a YAML validation error when a `format` key does not conform.
+- ([#12238](https://gijit.com/quarto-dev/quarto-cli/issues/12238)): Very long error (e.g. in Jupyter Notenook with backtrace) are now no more truncated in the console.
 
 ## Languages
 

src/core/log.ts

@@ -156,9 +156,23 @@ export class StdErrOutputHandler extends BaseHandler {
     return msg;
   }
   log(msg: string): void {
-    Deno.stderr.writeSync(
-      new TextEncoder().encode(msg),
-    );
+    const encoder = new TextEncoder();
+    const data = encoder.encode(msg);
+
+    let bytesWritten = 0;
+    while (bytesWritten < data.length) {
+      // Write the remaining portion of the buffer
+      const remaining = data.subarray(bytesWritten);
+      const written = Deno.stderr.writeSync(remaining);
+
+      // If we wrote 0 bytes, something is wrong - avoid infinite loop
+      if (written === 0) {
+        // Could add fallback handling here if needed
+        break;
+      }
+
+      bytesWritten += written;
+    }
   }
 }