1 files changed, 11 insertions, 5 deletions
diff --git a/deps/v8/src/torque/utils.cc b/deps/v8/src/torque/utils.cc
index 38862b31b0..4e757ac9e8 100644
--- a/deps/v8/src/torque/utils.cc
+++ b/deps/v8/src/torque/utils.cc
@@ -212,19 +212,25 @@ bool IsValidTypeName(const std::string& s) {
 }
 
 std::string CapifyStringWithUnderscores(const std::string& camellified_string) {
+  // Special case: JSAbc yields JS_ABC, not JSABC, for any Abc.
+  size_t js_position = camellified_string.find("JS");
+
   std::string result;
-  bool previousWasLower = false;
-  for (auto current : camellified_string) {
-    if (previousWasLower && isupper(current)) {
+  bool previousWasLowerOrDigit = false;
+  for (size_t index = 0; index < camellified_string.size(); ++index) {
+    char current = camellified_string[index];
+    if ((previousWasLowerOrDigit && isupper(current)) ||
+        (js_position != std::string::npos &&
+         index == js_position + strlen("JS"))) {
       result += "_";
     }
     if (current == '.' || current == '-') {
       result += "_";
-      previousWasLower = false;
+      previousWasLowerOrDigit = false;
       continue;
     }
     result += toupper(current);
-    previousWasLower = (islower(current));
+    previousWasLowerOrDigit = islower(current) || isdigit(current);
   }
   return result;
 }