Refactor error handling in package management API

I am hoping this will improve the ambiguous errors that originate from
package.el or quelpa.el.

core/autoload/packages.el

@@ -16,18 +16,14 @@
 
 (defmacro doom--condition-case! (&rest body)
   `(condition-case-unless-debug ex
-       (condition-case ex2
        (progn ,@body)
+     ('user-error
+      (print! (bold (red "  NOTICE: %s" ex))))
      ('file-error
       (print! (bold (red "  FILE ERROR: %s" (error-message-string ex2))))
       (print! "  Trying again...")
       (quiet! (doom-refresh-packages-maybe t))
-          ,@body))
-     ('user-error
-      (print! (bold (red "  ERROR: %s" ex))))
-     ('error
-      (doom--refresh-pkg-cache)
-      (print! (bold (red "  FATAL ERROR: %s" ex))))))
+      ,@body)))
 
 (defun doom--refresh-pkg-cache ()
   "Clear the cache for `doom-refresh-packages-maybe'."
@@ -60,7 +56,7 @@
 (defun doom-package-backend (name &optional noerror)
   "Get which backend the package NAME was installed with. Can either be elpa or
 quelpa. Throws an error if NOERROR is nil and the package isn't installed."
-  (cl-assert (symbolp name) t)
+  (cl-check-type name symbol)
   (cond ((assq name quelpa-cache)
          'quelpa)
         ((assq name package-alist)
@@ -75,7 +71,7 @@ quelpa. Throws an error if NOERROR is nil and the package isn't installed."
   "Determine whether NAME (a symbol) is outdated or not. If outdated, returns a
 list, whose car is NAME, and cdr the current version list and latest version
 list of the package."
-  (cl-assert (symbolp name) t)
+  (cl-check-type name symbol)
   (when-let* ((desc (cadr (assq name package-alist))))
     (let* ((old-version (package-desc-version desc))
            (new-version
@@ -100,15 +96,16 @@ list of the package."
 ;;;###autoload
 (defun doom-package-prop (name prop)
   "Return PROPerty in NAME's plist."
-  (cl-assert (symbolp name) t)
-  (cl-assert (keywordp prop) t)
+  (cl-check-type name symbol)
+  (cl-check-type prop keyword)
   (plist-get (cdr (assq name doom-packages)) prop))
 
 ;;;###autoload
 (defun doom-package-different-backend-p (name)
   "Return t if a package named NAME (a symbol) has a new backend than what it
 was installed with. Returns nil otherwise, or if package isn't installed."
-  (cl-assert (symbolp name) t)
+  (cl-check-type name symbol)
+  (doom-initialize-packages)
   (and (package-installed-p name)
        (let* ((plist (cdr (assq name doom-packages)))
               (old-backend (doom-package-backend name 'noerror))
@@ -119,7 +116,7 @@ was installed with. Returns nil otherwise, or if package isn't installed."
 (defun doom-package-different-recipe-p (name)
   "Return t if a package named NAME (a symbol) has a different recipe than it
 was installed with."
-  (cl-assert (symbolp name) t)
+  (cl-check-type name symbol)
   (when (package-installed-p name)
     (let ((quelpa-recipe (assq name quelpa-cache))
           (doom-recipe (assq name doom-packages)))
@@ -153,14 +150,17 @@ If INSTALLED-ONLY-P, only return packages that are installed."
 ;;;###autoload
 (defun doom-get-depending-on (name)
   "Return a list of packages that depend on the package named NAME."
+  (cl-check-type name symbol)
   (when (package-built-in-p name)
     (error "Can't get the dependency tree for built-in packages"))
-  (when-let* ((desc (cadr (assq name package-alist))))
-    (mapcar #'package-desc-name (package--used-elsewhere-p desc nil t))))
+  (if-let* ((desc (cadr (assq name package-alist))))
+      (mapcar #'package-desc-name (package--used-elsewhere-p desc nil t))
+    (error "Couldn't find %s, is it installed?" name)))
 
 ;;;###autoload
 (defun doom-get-dependencies-for (name &optional only)
   "Return a list of dependencies for a package."
+  (cl-check-type name symbol)
   (when (package-built-in-p name)
     (error "Can't get the dependency tree for built-in packages"))
   (package--get-deps name only))
@@ -262,6 +262,7 @@ Used by `doom//packages-install'."
 (defun doom-install-package (name &optional plist)
   "Installs package NAME with optional quelpa RECIPE (see `quelpa-recipe' for an
 example; the package name can be omitted)."
+  (cl-check-type name symbol)
   (doom-initialize-packages)
   (when (and (package-installed-p name)
              (not (package-built-in-p name)))
@@ -286,6 +287,8 @@ example; the package name can be omitted)."
 (defun doom-update-package (name &optional force-p)
   "Updates package NAME (a symbol) if it is out of date, using quelpa or
 package.el as appropriate."
+  (cl-check-type name symbol)
+  (doom-initialize-packages)
   (unless (package-installed-p name)
     (user-error "%s isn't installed" name))
   (when (doom-package-different-backend-p name)
@@ -294,10 +297,10 @@ package.el as appropriate."
     (let ((inhibit-message (not doom-debug-mode))
           (desc (cadr (assq name package-alist))))
       (pcase (doom-package-backend name)
-        ('quelpa
+        (`quelpa
          (let ((quelpa-upgrade-p t))
            (quelpa (assq name quelpa-cache))))
-        ('elpa
+        (`elpa
          (let* ((archive (cadr (assq name package-archive-contents)))
                 (packages
                  (if (package-desc-p archive)
@@ -313,6 +316,8 @@ package.el as appropriate."
 ;;;###autoload
 (defun doom-delete-package (name &optional force-p)
   "Uninstalls package NAME if it exists, and clears it from `quelpa-cache'."
+  (cl-check-type name symbol)
+  (doom-initialize-packages)
   (unless (package-installed-p name)
     (user-error "%s isn't installed" name))
   (let ((inhibit-message (not doom-debug-mode))
@@ -322,7 +327,8 @@ package.el as appropriate."
       (quelpa-save-cache)
       (setq quelpa-p t))
     (package-delete (cadr (assq name package-alist)) force-p)
-    (unless (package-installed-p name)
+    (when (or (not (package-installed-p name))
+              (package-built-in-p name))
       (let ((pkg-build-dir (expand-file-name (symbol-name name) quelpa-build-dir)))
         (when (and quelpa-p (file-directory-p pkg-build-dir))
           (delete-directory pkg-build-dir t)))