Bug 161464

Summary: const keyword should be allowed in strict mode
Product: WebKit Reporter: Jamie Pate <jamie.pate>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: ggaren, saam, ysuzuki
Priority: P2    
Version: Safari 9   
Hardware: Unspecified   
OS: Unspecified   

Description Jamie Pate 2016-08-31 16:30:01 PDT 
The 'const' keyword has 'basic support' from all major browsers according to http://kangax.github.io/compat-table/es6/

```
const foo = 123;
return (foo === 123);
```

Unfortunately, webkit throw an error if the `const` keyword is used in a strict context (via 'use strict'; ).

Steps to Reproduce:
<!DOCTYPE html>
<html>
<head></head>
<body style="white-space: pre-wrap">
<script> window.onerror = function(e) { alert(e);console.log.apply(console, arguments) }; </script>
<script>
/* jshint globalstrict: true */
/* jshint esnext: true */
'use strict';

function x() {
    const a = 1;
    return a === 1;
}
var result = 'failure';

try {
    result = x() ? 'success' : 'failure';
} catch (ex) { }
console.log(result);
alert(result);
</script>
</body>
</html>

Actual Results: "SyntaxError: Unexpected keyword 'const', Const declarations are not supported in strict mode."

Expected Results: "success" (script executed normally)

Platforms: OSX Safari 9.1.2, iOS webkit 602.1, Phantomjs 2.1.1
Comment 1 Saam Barati 2016-08-31 19:26:13 PDT 
Have you tried a webkit nightly? This has been fixed for a while.