[Fix #920] Implement boot support for cider-jack-in

CHANGELOG.md

@@ -8,6 +8,7 @@
 * [#903](https://github.com/clojure-emacs/cider/pull/903): Isolate
   `nrepl-client` connection logic from CIDER. New hooks `cider-connected-hook`
   and `cider-disconnected-hook`.
+* [#920](https://github.com/clojure-emacs/cider/issues/920): Support `cider-jack-in` for boot-based projects.
 
 ### Changes
 

README.md

@@ -531,22 +531,24 @@ enable `paredit` in the REPL buffer as well:
 ## Basic Usage
 
 The only requirement to use CIDER is to have a nREPL server to
-which it may connect. Many Clojurians favour the use of the Leiningen tool
-to start a nREPL server, but the use of Leiningen is not a prerequisite to use
-CIDER (but it's required if you want to use the `cider-jack-in` command).
+which it may connect. Many Clojurians favour the use of the Leiningen or Boot tools
+to start an nREPL server, but the use of Leiningen or Boot is not a prerequisite to use
+CIDER (but it *is* required if you want to use the `cider-jack-in` command).
 
-### Setting up a Leiningen project (optional)
+### Setting up a Leiningen or Boot project (optional)
 
-[Leiningen](http://leiningen.org/) is the de facto standard
-build/project management tool for Clojure.  It has a similar scope to
-the Maven build tool favoured by Java developers (Leiningen actually
-reuses many things from the Maven ecosystem).
+[Leiningen](http://leiningen.org/) is the de facto standard build/project
+management tool for Clojure. [Boot](http://boot-clj.com/) is a newer build tool
+offering abstractions and libraries to construct more complex build
+scenarios. Both have a similar scope to the Maven build tool favoured by Java
+developers (and they actually reuse many things from the Maven ecosystem).
 
 CIDER features a command called `cider-jack-in` that will start an nREPL server
-for a particular Leiningen project and connect to it automatically.  This
-functionality depends on Leiningen 2.x (preferably 2.5+). Older versions are not
-supported. Follow the installation instructions on Leiningen's web site to get
-it up and running and afterwards create a project like this:
+for a particular Leiningen or Boot project and connect to it automatically.
+This functionality depends on Leiningen 2.x (preferably 2.5+) or Boot
+2.0.0+. Older versions are not supported. For Leiningen, follow the installation
+instructions on its web site to get it up and running and afterwards create a
+project like this:
 
 ```
 $ lein new demo
@@ -556,12 +558,12 @@ The two main ways to obtain an nREPL connection are discussed in the following s
 
 ### Launch a nREPL server and client from Emacs
 
-Simply open in Emacs a file belonging to your `lein` project (like
+Simply open in Emacs a file belonging to your `lein` or `boot` project (like
 `foo.clj`) and type <kbd>M-x cider-jack-in</kbd>. This will start a nREPL with
 all the deps loaded in, plus an `CIDER` client connected to it.
 
 Alternative you can use <kbd>C-u M-x cider-jack-in</kbd> to specify the name of
-a lein project, without having to visit any file in it.
+a `lein` or `boot` project, without having to visit any file in it.
 
 ### Connect to a running nREPL server
 
@@ -572,6 +574,12 @@ You can go to your project's dir in a terminal and type there
 $ lein repl
 ```
 
+Or with Boot:
+
+```
+$ boot repl wait
+```
+
 Alternatively you can start nREPL either manually or by the facilities provided by your
 project build tool (Maven, etc).
 

cider.el

@@ -84,6 +84,20 @@ version from the CIDER package or library.")
   :type 'string
   :group 'cider)
 
+(defcustom cider-boot-command
+  "boot"
+  "The command used to execute Boot."
+  :type 'string
+  :group 'cider
+  :package-version '(cider . "0.9.0"))
+
+(defcustom cider-boot-parameters
+  "repl -s wait"
+  "Params passed to boot to start an nREPL server via `cider-jack-in'."
+  :type 'string
+  :group 'cider
+  :package-version '(cider . "0.9.0"))
+
 (defcustom cider-known-endpoints nil
   "Specify a list of custom endpoints where each endpoint is a list.
 For example: '((\"label\" \"host\" \"port\")).
@@ -122,29 +136,45 @@ Sub-match 1 must be the project path.")
   (interactive)
   (message "CIDER %s" (cider--version)))
 
+(defun cider-command-present-p (project-type)
+  (pcase project-type
+    ("lein" 'cider--lein-present-p)
+    ("boot" 'cider--boot-present-p)))
+
+(defun cider-jack-in-command (project-type)
+  (pcase project-type
+    ("lein" cider-lein-command)
+    ("boot" cider-boot-command)))
+
+(defun cider-jack-in-params (project-type)
+  (pcase project-type
+    ("lein" cider-lein-parameters)
+    ("boot" cider-boot-parameters)))
+
 ;;;###autoload
 (defun cider-jack-in (&optional prompt-project)
   "Start a nREPL server for the current project and connect to it.
 If PROMPT-PROJECT is t, then prompt for the project for which to
 start the server."
   (interactive "P")
   (setq cider-current-clojure-buffer (current-buffer))
-  (if (cider--lein-present-p)
-      (let* ((nrepl-create-client-buffer-function  #'cider-repl-create)
-             (project (when prompt-project
-                        (read-directory-name "Project: ")))
-             (project-dir (nrepl-project-directory-for
-                           (or project (nrepl-current-dir))))
-             (lein-params (if prompt-project
-                              (read-string (format "nREPL server command: %s "
-                                                   cider-lein-command)
-                                           cider-lein-parameters)
-                            cider-lein-parameters))
-             (cmd (format "%s %s" cider-lein-command lein-params)))
-        (when (nrepl-check-for-repl-buffer nil project-dir)
-          (nrepl-start-server-process project-dir cmd)))
-    (message "The %s executable (specified by `cider-lein-command') isn't on your exec-path"
-             cider-lein-command)))
+  (let ((project-type (cider-project-type)))
+    (if (funcall (cider-command-present-p project-type))
+        (let* ((nrepl-create-client-buffer-function  #'cider-repl-create)
+               (project (when prompt-project
+                          (read-directory-name "Project: ")))
+               (project-dir (nrepl-project-directory-for
+                             (or project (nrepl-current-dir))))
+               (params (if prompt-project
+                           (read-string (format "nREPL server command: %s "
+                                                (cider-jack-in-params project-type))
+                                        (cider-jack-in-params project-type))
+                         (cider-jack-in-params project-type)))
+               (cmd (format "%s %s" (cider-jack-in-command project-type) params)))
+          (when (nrepl-check-for-repl-buffer nil project-dir)
+            (nrepl-start-server-process project-dir cmd)))
+      (message "The %s executable (specified by `cider-lein-command' or `cider-boot-command') isn't on your exec-path"
+               (cider-jack-in-command project-type)))))
 
 ;;;###autoload
 (defun cider-connect (host port)
@@ -239,6 +269,18 @@ use `cider-ps-running-nrepls-command' and `cider-ps-running-nrepl-path-regexp-li
           (setq paths (cons (match-string 1) paths)))))
     (-distinct paths)))
 
+(defun cider-project-type ()
+  "Determine the type, either leiningen or boot, of the current project.
+If both project file types are present, prompt the user to choose."
+  (let* ((default-directory (nrepl-project-directory-for (nrepl-current-dir)))
+         (lein-project-exists (file-exists-p "project.clj"))
+         (boot-project-exists (file-exists-p "build.boot")))
+    (cond ((and lein-project-exists boot-project-exists)
+           (completing-read "Which command should be used? " '("lein" "boot") nil
+                            t "lein"))
+          (lein-project-exists "lein")
+          (boot-project-exists "boot"))))
+
 ;; TODO: Implement a check for `cider-lein-command' over tramp
 (defun cider--lein-present-p ()
   "Check if `cider-lein-command' is on the `exec-path'.
@@ -248,6 +290,14 @@ In case `default-directory' is non-local we assume the command is available."
       (executable-find cider-lein-command)
       (executable-find (concat cider-lein-command ".bat"))))
 
+(defun cider--boot-present-p ()
+  "Check if `cider-boot-command' is on the `exec-path'.
+
+In case `default-directory' is non-local we assume the command is available."
+  (or (file-remote-p default-directory)
+      (executable-find cider-boot-command)
+      (executable-find (concat cider-boot-command ".exe"))))
+
 (defun cider--connected-handler ()
   "Handle cider initialization after nREPL connection has been established.
 This function is appended to `nrepl-connected-hook' in the client process

nrepl-client.el

@@ -264,7 +264,8 @@ Bind the value of the provided KEYS and execute BODY."
 (defun nrepl-project-directory-for (dir-name)
   "Return the project directory for the specified DIR-NAME."
   (when dir-name
-    (locate-dominating-file dir-name "project.clj")))
+    (or (locate-dominating-file dir-name "project.clj")
+        (locate-dominating-file dir-name "build.boot"))))
 
 (defun nrepl-check-for-repl-buffer (endpoint project-directory)
   "Check whether a matching connection buffer already exists.