LibJS: Add side-effect-free version of Value::to_string()

There are now two API's on Value:

- Value::to_string(Interpreter&) -- may throw.
- Value::to_string_without_side_effects() -- will never throw.

These are some pretty big sweeping changes, so it's possible that I did
some part the wrong way. We'll work it out as we go. :^)

Fixes #2123.

1 files changed, 10 insertions, 4 deletions

diff --git a/Libraries/LibWeb/Bindings/WindowObject.cpp b/Libraries/LibWeb/Bindings/WindowObject.cpp
index bab0a17316..1c1dcedce4 100644
--- a/Libraries/LibWeb/Bindings/WindowObject.cpp
+++ b/Libraries/LibWeb/Bindings/WindowObject.cpp
@@ -98,8 +98,11 @@ JS::Value WindowObject::alert(JS::Interpreter& interpreter)
     if (!impl)
         return {};
     String message = "";
-    if (interpreter.argument_count())
-        message = interpreter.argument(0).to_string();
+    if (interpreter.argument_count()) {
+        message = interpreter.argument(0).to_string(interpreter);
+        if (interpreter.exception())
+            return {};
+    }
     impl->alert(message);
     return JS::js_undefined();
 }
@@ -110,8 +113,11 @@ JS::Value WindowObject::confirm(JS::Interpreter& interpreter)
     if (!impl)
         return {};
     String message = "";
-    if (interpreter.argument_count())
-        message = interpreter.argument(0).to_string();
+    if (interpreter.argument_count()) {
+        message = interpreter.argument(0).to_string(interpreter);
+        if (interpreter.exception())
+            return {};
+    }
     return JS::Value(impl->confirm(message));
 }