figwheel emacs cider stuff

figwheel-emacs-cider.txt

## Using Emacs CIDER as the Figwheel REPL tool

project.clj should have this line:

```
  :figwheel { :nrepl-port 7888 }
```
At the defproject-level.

It enables external tools to connect to the Figwheel REPL. To connect
Emacs CIDER mode to the Figwheel REPL, do the following steps.

### 1. Install CIDER and Clojure mode.

Clojure-mode should be pretty much from the same time period than
CIDER. For example these versions from Emacs package manager (source:
melpa) did the trick:

* cider 20150531.252
* clojure-mode 20150517.6

### 2. Set up leiningen plugins

Let's install plugins locally to:

```
~.lein/profiles.clj
```

The contents should look like this:

```
{:user {:plugins [[cider/cider-nrepl "0.9.0-SNAPSHOT"]]
        :dependencies [[org.clojure/tools.nrepl "0.2.7"]]}}
```

### 3. The startup sequence

 1. Start figwheel like in the previous section, e.g. `rlwrap lein figwheel [build id if you use such things]`
 2. Start your main app which connects to lein figwheel via websocket 
 3. Run M-x `cider-connect` in Emacs. It asks for host (localhost) and port (7888)
 4. In the prompt you get after the jack-in, run these commands:
 `(use 'figwheel-sidecar.repl-api)`
 `(cljs-repl)`

After those steps you should have the same REPL available inside Emacs
than you did in shell in the previous section. But you'll have all the
CIDER Clojure goodness available instead of just dumb command-line.

To make things easier, you can also add these to your .emacs or
emacs.d/init.el:

```
(add-hook 'cider-connected-hook '(lambda ()
                                   (cider-interactive-eval
                                    "(use 'figwheel-sidecar.repl-api)\n(cljs-repl)\n")))

(defun figwheel-connect ()
  (interactive)
  (cider-connect "localhost" "7888"))
```

After that, all you have to do in emacs is M-x figwheel-connect and press
<enter>. Figwheel has to be running already of course.

[Some more documentation on Figwheel + NREPL](https://github.com/bhauman/lein-figwheel/wiki/Using-the-Figwheel-REPL-within-NRepl) in case you are having trouble.

[The CIDER site](https://github.com/clojure-emacs/cider).

[CIDER nREPL site](https://github.com/clojure-emacs/cider-nrepl).

it seems not working with the latest figwheel

I still get:
user-error: cider-eval-last-sexp' needs a ClojureScript REPL. If you don't know what that means, you probably need to jack-in (C-c M-J').