test(dirvish): cover cj/get-project-root with stubbed APIs

`cj/get-project-root' was already in the right shape (pure dispatch over `projectile-project-root' and `project-current'), but had no tests.  Add four covering the four meaningful states: projectile finds a root, projectile returns nil and project.el finds one, projectile errors and the wrapper falls through to project.el, and neither finds anything.  The tests stub all three external symbols (`projectile-project-root', `project-current', `project-root') so they exercise the function without a project on disk.

1 files changed, 71 insertions, 0 deletions

diff --git a/tests/test-dirvish-config-get-project-root.el b/tests/test-dirvish-config-get-project-root.el
new file mode 100644
index 00000000..91d322f9
--- /dev/null
+++ b/tests/test-dirvish-config-get-project-root.el
@@ -0,0 +1,71 @@
+;;; test-dirvish-config-get-project-root.el --- Tests for cj/get-project-root -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; `cj/get-project-root' picks projectile when available, falls back to
+;; project.el, and returns nil when neither finds a project.  These tests
+;; stub the two underlying APIs (`projectile-project-root',
+;; `project-current', `project-root') so the function can be exercised
+;; without an actual project on disk.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'package)
+
+(setq package-user-dir (expand-file-name "elpa" user-emacs-directory))
+(package-initialize)
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(add-to-list 'load-path (expand-file-name "elpa/dirvish-2.3.0/extensions"
+                                          user-emacs-directory))
+(require 'user-constants)
+(require 'keybindings)
+(require 'dirvish-config)
+
+;; Make sure both APIs are at least fbound so the `fboundp' guards in
+;; `cj/get-project-root' fire correctly under cl-letf.
+(unless (fboundp 'projectile-project-root)
+  (defalias 'projectile-project-root #'ignore))
+(unless (fboundp 'project-current)
+  (defalias 'project-current #'ignore))
+(unless (fboundp 'project-root)
+  (defalias 'project-root #'ignore))
+
+(ert-deftest test-cj-get-project-root-projectile-wins ()
+  "Normal: when projectile returns a root, that root is returned."
+  (cl-letf (((symbol-function 'projectile-project-root)
+             (lambda (&rest _) "/home/me/code/proj/"))
+            ((symbol-function 'project-current)
+             (lambda (&rest _) (error "project-current should not be reached"))))
+    (should (equal (cj/get-project-root) "/home/me/code/proj/"))))
+
+(ert-deftest test-cj-get-project-root-falls-back-to-project-el ()
+  "Normal: when projectile returns nil, project.el's root wins."
+  (cl-letf (((symbol-function 'projectile-project-root)
+             (lambda (&rest _) nil))
+            ((symbol-function 'project-current)
+             (lambda (&rest _) '(vc Git "/home/me/repo/")))
+            ((symbol-function 'project-root)
+             (lambda (_) "/home/me/repo/")))
+    (should (equal (cj/get-project-root) "/home/me/repo/"))))
+
+(ert-deftest test-cj-get-project-root-projectile-errors-then-fallback ()
+  "Boundary: projectile signaling an error is suppressed; fallback runs."
+  (cl-letf (((symbol-function 'projectile-project-root)
+             (lambda (&rest _) (error "projectile not initialized")))
+            ((symbol-function 'project-current)
+             (lambda (&rest _) '(vc Git "/home/me/repo/")))
+            ((symbol-function 'project-root)
+             (lambda (_) "/home/me/repo/")))
+    (should (equal (cj/get-project-root) "/home/me/repo/"))))
+
+(ert-deftest test-cj-get-project-root-no-project-returns-nil ()
+  "Boundary: neither projectile nor project.el find anything."
+  (cl-letf (((symbol-function 'projectile-project-root)
+             (lambda (&rest _) nil))
+            ((symbol-function 'project-current)
+             (lambda (&rest _) nil)))
+    (should-not (cj/get-project-root))))
+
+(provide 'test-dirvish-config-get-project-root)
+;;; test-dirvish-config-get-project-root.el ends here