util: do not reduce to a single line if not appropriate using inspect

This makes sure entries are not lined up on a single line if the
content contains any new line. That would otherwise cause confusing
output.
Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>
PR-URL: #41083
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: BridgeAR

lib/internal/util/inspect.js

@@ -1931,8 +1931,11 @@ function reduceToSingleString(
 conststart=output.length+ctx.indentationLvl+
 braces[0].length+base.length+10;
 if(isBelowBreakLength(ctx,output,start,base)){
-return`${base ? `${base} ` : ''}${braces[0]}${join(output,', ')}`+
-` ${braces[1]}`;
+constjoinedOutput=join(output,', ');
+if(!joinedOutput.includes('\n')){
+return`${base ? `${base} ` : ''}${braces[0]}${joinedOutput}`+
+` ${braces[1]}`;
+}
 }
 }
 }

test/parallel/test-util-inspect.js

@@ -2631,6 +2631,24 @@ assert.strictEqual(
 
 assert.strictEqual(out,expected);
 
+// Array grouping should prevent lining up outer elements on a single line.
+obj=[[[1,2,3,4,5,6,7,8,9]]];
+
+out=util.inspect(obj,{compact: 3});
+
+expected=[
+'[',
+' [',
+' [',
+' 1, 2, 3, 4, 5,',
+' 6, 7, 8, 9',
+' ]',
+' ]',
+']',
+].join('\n');
+
+assert.strictEqual(out,expected);
+
 // Verify that array grouping and line consolidation does not happen together.
 obj={
 a: {