Add tests for the dirconfig cache

The mtime-keyed cache around projectile-parse-dirconfig-file had no
direct coverage. Cover the four invariants that matter: a cache hit
on repeat calls, a re-parse when mtime advances, no caching of a nil
result for a missing file, and entry removal via
projectile-invalidate-cache (the path that previously crashed in #1854).

1 files changed, 59 insertions, 0 deletions

diff --git a/test/projectile-test.el b/test/projectile-test.el
index 4a20e92..f874a83 100644
--- a/test/projectile-test.el
+++ b/test/projectile-test.el
@@ -574,6 +574,65 @@ Just delegates OPERATION and ARGS for all operations except for`shell-command`'.
       (expect (projectile-parse-dirconfig-file)
               :to-equal '(nil ("keep-this") nil)))))
 
+(describe "dirconfig cache"
+  (before-each
+    (clrhash projectile--dirconfig-cache))
+  (it "memoizes the parsed result while the file is unchanged"
+    (projectile-test-with-sandbox
+     (projectile-test-with-files
+      ("project/.projectile")
+      (let ((root (file-truename (expand-file-name "project/"))))
+        (with-temp-file (expand-file-name ".projectile" root)
+          (insert "-foo\n"))
+        (spy-on 'projectile-project-root :and-return-value root)
+        (spy-on 'projectile--parse-dirconfig-file-uncached
+                :and-call-through)
+        (projectile-parse-dirconfig-file)
+        (projectile-parse-dirconfig-file)
+        (projectile-parse-dirconfig-file)
+        (expect 'projectile--parse-dirconfig-file-uncached
+                :to-have-been-called-times 1)))))
+  (it "re-parses when the dirconfig file's mtime changes"
+    (projectile-test-with-sandbox
+     (projectile-test-with-files
+      ("project/.projectile")
+      (let* ((root (file-truename (expand-file-name "project/")))
+             (dirconfig (expand-file-name ".projectile" root)))
+        (with-temp-file dirconfig (insert "-foo\n"))
+        (spy-on 'projectile-project-root :and-return-value root)
+        (expect (cadr (projectile-parse-dirconfig-file))
+                :to-equal '("foo"))
+        ;; Force a distinct mtime — file-attribute-modification-time has
+        ;; second-level resolution on some filesystems.
+        (set-file-times dirconfig (time-add (current-time) 5))
+        (with-temp-file dirconfig (insert "-bar\n"))
+        (set-file-times dirconfig (time-add (current-time) 5))
+        (expect (cadr (projectile-parse-dirconfig-file))
+                :to-equal '("bar"))))))
+  (it "returns nil and does not cache when the dirconfig file is absent"
+    (projectile-test-with-sandbox
+     (projectile-test-with-files
+      ("project/")
+      (let ((root (file-truename (expand-file-name "project/"))))
+        (spy-on 'projectile-project-root :and-return-value root)
+        (expect (projectile-parse-dirconfig-file) :to-be nil)
+        (expect (gethash root projectile--dirconfig-cache) :to-be nil)))))
+  (it "is cleared for the project by projectile-invalidate-cache"
+    (projectile-test-with-sandbox
+     (projectile-test-with-files
+      ("project/.projectile")
+      (let ((root (file-truename (expand-file-name "project/"))))
+        (with-temp-file (expand-file-name ".projectile" root)
+          (insert "-foo\n"))
+        (spy-on 'projectile-project-root :and-return-value root)
+        ;; Avoid touching the on-disk cache file or recentf during the test.
+        (spy-on 'projectile-persistent-cache-p :and-return-value nil)
+        (spy-on 'recentf-cleanup)
+        (projectile-parse-dirconfig-file)
+        (expect (gethash root projectile--dirconfig-cache) :not :to-be nil)
+        (projectile-invalidate-cache nil)
+        (expect (gethash root projectile--dirconfig-cache) :to-be nil))))))
+
 (describe "projectile-get-project-directories"
   (it "gets the list of project directories"
     (spy-on 'projectile-project-root :and-return-value "/my/root/")