How do you do examine a Google Chrome extension before installing it?

Question

I found what appears to be a very cool extension for Google Chrome - a Dropbox addin that lets you compare versions of files in your Dropbox by using a diff tool.

Like most Chrome extensions, this one has some warnings about permissions:

This extension can access:

• Your data on dropbox.com and www.dropbox.com
• All data on your computer and the websites you visit

My default instinct is to download the source of the extension and look through it, but the only button I see is "Add to Chrome"

Since Google Chrome is supposed to be "open source," and there is a nice community repository for downloading extensions, I would have expected to see something like "download the source code."

My questions are:

• How do you download the source for an extension prior to installing it?
• What other ways can you "do your homework" and make sure an extension is safe besides looking at reviews and/or looking through the source code?

Answer 1

There is Extension Gallery and Web Store Inspector extension that would show you source code and tell which features and API methods are used.