Check JavaScript for Unexpected Assignments

I have some JavaScript that I want to check to make sure I have no occurrences of using the assignment operator (=) as opposed to the equality operator (==). I've looked at JShint, JSLint, and the Google Closure Compiler. Unfortunately, no matter how I set the previous two tools, I get mounds of junk "errors" about all kinds of nit-picky little things, and the Google Closure Compiler does not detect this very common error.

Are there any tools I may use as an alternative to the three above? Really, I just want to check for this one error. I don't care about anything else.