Looking for a Javascript workbench

I'm looking for a proper javascript workbench.

There are a lot of workbenches that focus on html, but I can't find any that focus on Javascript as a language. In particular:

• It should dump expression values implicitly or at least make it easy to dump them. I don't want to code DOM manipulations just to see some results. If the result is anything more complex than a string or a number, it would be nice if I can explore the contents of the object interactively.
• It should be more than a simple REPL: I want to edit and re-execute a code snippet in a convenient way. Ideally I also want to save them somehow. If it's an offline tool, that would be the file system. If it's online, it may just give me a url.

Examples for tools that violate the first point are JsFiddle, Codepen, JsBin and many others.

Examples for tools that violate the second point are Firebug and the various in-browser javascript consoles.

An example for what I want that isn't geared to Javascript is LinqPad: Despite the name it isn't only useful for linq-related jobs but rather is a full-fledged IDE for small C#/VB/F# snippets. It also has the following additional perks:

• Tab completion.
• Installation of packages and safe those dependencies along with the code snippet. (An analogous Javascript tool would probably use npm rather than NuGet.)
• Each snippet can be categorized as expression, statement or program. An expression is dumped without the need for any special method call, and is the default. I can write "1 + 2" and get "3" on hitting F5. Then I can save that snippet in case I forget.

Does anybody know about a tool that fits my description?