[Fix #451] Make the function determining the project directory customizable (#452)

Author: mbuczko

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [#443](https://github.com/clojure-emacs/clojure-mode/issues/443): Fix behavior of `clojure-forward-logical-sexp` and `clojure-backward-logical-sexp` with conditional macros.
 * [#429](https://github.com/clojure-emacs/clojure-mode/issues/429): Fix a bug causing last occurrence of expression sometimes is not replaced when using `move-to-let`.
 * [#423](https://github.com/clojure-emacs/clojure-mode/issues/423): Make `clojure-match-next-def` more robust against zero-arity def-like forms.
+* [#451](https://github.com/clojure-emacs/clojure-mode/issues/451): Make project root directory calculation customized by `clojure-project-root-function`
 
 ### New features
 

clojure-mode.el

@@ -192,6 +192,12 @@ Out-of-the box `clojure-mode' understands lein, boot and gradle."
           (and (listp value)
                (cl-every 'stringp value))))
 
+(defcustom clojure-project-root-function #'clojure-project-root-path
+  "Function to locate clojure project root directory."
+  :type 'function
+  :risky t
+  :package-version '(clojure-mode . "5.7.0"))
+
 (defcustom clojure-refactor-map-prefix (kbd "C-c C-r")
   "Clojure refactor keymap prefix."
   :type 'string
@@ -1604,6 +1610,13 @@ nil."
 (defun clojure-project-dir (&optional dir-name)
   "Return the absolute path to the project's root directory.
 
+Call is delegated down to `clojure-project-root-function' with
+optional DIR-NAME as argument."
+  (funcall clojure-project-root-function dir-name))
+
+(defun clojure-project-root-path (&optional dir-name)
+  "Return the absolute path to the project's root directory.
+
 Use `default-directory' if DIR-NAME is nil.
 Return nil if not inside a project."
   (let* ((dir-name (or dir-name default-directory))