util: limit inspection output size to 128 MB

lib/util.js

@@ -634,7 +634,7 @@ function formatValue(ctx, value, recurseTimes) {
     return ctx.stylize('null', 'null');
   }
 
-  if (ctx.stop) {
+  if (ctx.stop !== undefined) {
     const name = getConstructorName(value) || value[Symbol.toStringTag];
     return ctx.stylize(`[${name || 'Object'}]`, 'special');
   }
@@ -897,6 +897,13 @@ function formatRaw(ctx, value, recurseTimes) {
   const budget = ctx.budget[ctx.indentationLvl] || 0;
   const newLength = budget + res.length;
   ctx.budget[ctx.indentationLvl] = newLength;
+  // If any indentationLvl exceeds this limit, limit further inspecting to the
+  // minimum. Otherwise the recursive algorithm might continue inspecting the
+  // object even tough the maximum string size (~2 ** 28 on 32 bit systems and
+  // ~2 ** 64) exceeded. The actual output is not limited at exactly 2 ** 27 but
+  // a bit higher. This depends on the object shape.
+  // This limit also makes sure that huge objects don't block the event loop
+  // significantly.
   if (newLength > 2 ** 27) {
     ctx.stop = true;
   }