repl: use object writer for thrown errors

This makes us use the defaults that were set for the REPL, i.e.
aligns with the printing of expression completion values, and in
particular enables color support.

PR-URL: #26361
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Anto Aravinth <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: addaleax

lib/repl.js

@@ -416,7 +416,7 @@ function REPLServer(prompt,
                                       (_, pre, line) => pre + (line - 1));
           }
         }
-        errStack = util.inspect(e);
+        errStack = self.writer(e);
 
         // Remove one line error braces to keep the old style in place.
         if (errStack[errStack.length - 1] === ']') {
@@ -426,7 +426,7 @@ function REPLServer(prompt,
     }
 
     if (errStack === '') {
-      errStack = `Thrown: ${util.inspect(e)}\n`;
+      errStack = `Thrown: ${self.writer(e)}\n`;
     } else {
       const ln = errStack.endsWith('\n') ? '' : '\n';
       errStack = `Thrown:\n${errStack}${ln}`;

test/parallel/test-repl-pretty-stack.js

@@ -6,7 +6,7 @@ const assert = require('assert');
 const repl = require('repl');
 
 
-function run({ command, expected }) {
+function run({ command, expected, ...extraREPLOptions }) {
   let accum = '';
 
   const inputStream = new ArrayStream();
@@ -19,7 +19,8 @@ function run({ command, expected }) {
     input: inputStream,
     output: outputStream,
     terminal: false,
-    useColors: false
+    useColors: false,
+    ...extraREPLOptions
   });
 
   r.write(`${command}\n`);
@@ -44,6 +45,18 @@ const tests = [
     command: 'throw new Error(\'Whoops!\')',
     expected: 'Thrown:\nError: Whoops!\n'
   },
+  {
+    command: '(() => { const err = Error(\'Whoops!\'); ' +
+             'err.foo = \'bar\'; throw err; })()',
+    expected: 'Thrown:\n{ Error: Whoops!\n    at repl:1:22 foo: \'bar\' }\n',
+  },
+  {
+    command: '(() => { const err = Error(\'Whoops!\'); ' +
+             'err.foo = \'bar\'; throw err; })()',
+    expected: 'Thrown:\n{ Error: Whoops!\n    at repl:1:22 foo: ' +
+              "\u001b[32m'bar'\u001b[39m }\n",
+    useColors: true
+  },
   {
     command: 'foo = bar;',
     expected: 'Thrown:\nReferenceError: bar is not defined\n'