Link within a javascript_tag block produces a parser error

The following template:
```
<% javascript_tag do %>
  // <http://example.com>
<% end %>
```

Produces this error on line 2:
```
Unexpected Token. Expected: `TOKEN_IDENTIFIER, TOKEN_AT, TOKEN_ERB_START,TOKEN_WHITESPACE, or TOKEN_NEWLINE`, found: `TOKEN_SLASH`. (Herb Parser  UNEXPECTED_ERROR)
```

The trigger seems to be the bracket?