Load the known projects before listing them

CHANGELOG.md

@@ -26,6 +26,7 @@
 
 ### Bugs fixed
 
+- [#2171](https://github.com/bbatsov/projectile/pull/2171): The commands that list the known projects now load the persisted list first. They read the `projectile-known-projects` variable, which stays nil until the same-named accessor loads it from disk and which nothing loads at startup - so whichever of them you reached for first in a session offered nothing. `projectile-find-file-in-known-projects` completed over an empty list; `projectile-vc`, `projectile-remove-known-project` and the "Switch to project" prompt of `projectile-require-project-root` were affected too.
 - [#2170](https://github.com/bbatsov/projectile/pull/2170): Navigating a search results buffer while the scan is still running is no longer undone by the next chunk. Each redraw ended by going to the top of the buffer, so point jumped back on every batch of matches; it now stays where you left it.
 - [#2167](https://github.com/bbatsov/projectile/pull/2167): The Emacs Lisp search scanner no longer decompresses or decrypts the files it reads. It went through `file-name-handler-alist`, so every archive in the candidate set was run through gzip and every `.gpg` handed to EPA - work discarded a moment later as binary, and on an encrypted file a passphrase prompt in the middle of a project search.
   - Matches inside compressed files are no longer reported by that scanner, which is what the ripgrep path already did.

projectile.el

@@ -3138,7 +3138,7 @@ See also `projectile-acquire-root'."
       dir
     (cond
      ((eq projectile-require-project-root 'prompt) (projectile-completing-read
-                                                    "Switch to project: " projectile-known-projects
+                                                    "Switch to project: " (projectile-known-projects)
                                                     :category 'projectile-project
                                                     :caller 'projectile-read-project))
      (projectile-require-project-root (user-error "Projectile cannot find a project definition in %s" default-directory))
@@ -11561,7 +11561,7 @@ directory to open."
                     (list
                      (projectile-completing-read
                       "Open project VC in: "
-                      projectile-known-projects
+                      (projectile-known-projects)
                       :category 'projectile-project
                       :caller 'projectile-read-project))))
   (unless project-root
@@ -13885,15 +13885,15 @@ This command will first prompt for the directory the file is in."
 
 (defun projectile-all-project-files ()
   "Get a list of all files in all projects."
-  (projectile-project-group-files projectile-known-projects))
+  (projectile-project-group-files (projectile-known-projects)))
 
 ;;;###autoload
 (defun projectile-find-file-in-known-projects ()
   "Jump to a file in any of the known projects.
 This is `projectile-find-file-in-projects' over every project you have
 ever visited."
   (interactive)
-  (projectile-find-file-in-projects projectile-known-projects
+  (projectile-find-file-in-projects (projectile-known-projects)
                                     "Find file in projects: "))
 
 (defun projectile-keep-project-p (project)
@@ -13996,7 +13996,7 @@ projects removed."
 (defun projectile-remove-known-project (&optional project)
   "Remove PROJECT from the list of known projects."
   (interactive (list (projectile-completing-read
-                      "Remove from known projects: " projectile-known-projects
+                      "Remove from known projects: " (projectile-known-projects)
                       :action 'projectile-remove-known-project
                       :category 'projectile-project
                       :caller 'projectile-read-project)))

test/projectile-known-projects-test.el

@@ -472,4 +472,21 @@
           (projectile-ignored-project-function nil))
       (expect (projectile-ignored-project-p "/anything/") :to-be nil))))
 
+(describe "commands that list the known projects"
+  ;; `projectile-known-projects' the variable is nil until the same-named
+  ;; accessor loads it from disk, and nothing loads it at startup.  Reading
+  ;; the variable therefore handed an empty list to whichever command asked
+  ;; first in a session - `s-p F' completed over nothing at all.
+  (it "loads the persisted list rather than reading the empty variable"
+    (let ((projectile-known-projects nil)
+          (loaded nil))
+      (spy-on 'projectile-load-known-projects :and-call-fake
+              (lambda () (setq loaded t
+                               projectile-known-projects '("/a/" "/b/"))))
+      (spy-on 'projectile-project-group-files :and-return-value '("/a/x"))
+      (projectile-all-project-files)
+      (expect loaded :to-be-truthy)
+      (expect 'projectile-project-group-files
+              :to-have-been-called-with '("/a/" "/b/")))))
+
 ;;; projectile-known-projects-test.el ends here